Multi-Purpose
                                   Regional
                                 Transmission
 100% Deep Transmission Integration for 7% Urban, 6% Multipurpose, 5% Regional
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                    10s AMT
                                 CI Engine[a]
                           2024 MY 7L, 200 hp Engine
                           2024 MY 7L, 270 hp Engine
                          2024 MY 11L, 345 hp Engine
                           2024 MY 15L 455hp Engine
                      100% Idle Reduction = Neutral Idle
                     100% improved axle lubrication: 0.5%
                  100% Steer Tires with CRR 6.7 kg/metric ton
                  100% Drive Tires with CRR 7.1 kg/metric ton
                            Weight Reduction 200 lb
Note:
[a] SI engines were not simulated in GEM
Table V-15: GEM Inputs for Benchmarked MY 2027 Vocational Vehicles
                                  Class 2b-5
                                   Class 6-7
                                    Class 8
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                 Transmission
 100% Deep Transmission Integration for 7% Urban, 6% Multipurpose, 5% Regional
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                     5s AT
                                    10s AMT
                                 CI Engine[a]
                           2027 MY 7L, 200 hp Engine
                           2027 MY 7L, 270 hp Engine
                          2027 MY 11L, 345 hp Engine
                           2027 MY 15L 455hp Engine
                       100% Idle Reduction = Stop-Start
                  100% Steer Tires with CRR 6.4 kg/metric ton
                  100% Drive Tires with CRR 7.0 kg/metric ton
                            Weight Reduction 200 lb
Note:
[a] SI engines were not simulated in GEM
Next we identified the best performing baseline vehicle in each weight class group (one for HHD, one for MHD and one for LHD) and normalized the baseline GEM results to the performance of that vehicle.  A complete description of this normalization process is found in the draft RIA Chapter 2.  We then applied our actual projected technology adoption rates, including hybrid powertrains and stop-start idle reduction, to normalized-benchmarked vehicles in each of the nine subcategories.  The proposed standards then were calculated by multiplying the normalized baseline vehicle GEM result by an average percent improvement for each weight class group.  For example, the GEM results from applying the projected technology mix for MY 2021 MHD CI vocational vehicles were a 5 percent improvement in the Regional MHD subcategory, 7 percent improvement in the MHD Multipurpose subcategory, and 8 percent improvement in the MHD Urban subcategory.  To achieve standards with equivalent stringency, we multiplied each normalized baseline vehicle's GEM performance by the numerical average of those simulated improvements, 6.6 percent.  Without comparable stringency across the subcategories, manufacturers could have an incentive to select a subcategory strategically to have a less stringent standard, rather than certify vehicles in the subcategory that best matches the vehicles' expected use patterns.  By setting the standards at the same percent reduction from each weight class group of normalized-benchmarked vehicles, we would expect to minimize any incentive for a manufacturer to certify a vocational vehicle in an inappropriate subcategory.
We request comment on using this approach to normalize the standards.  Commenters are encouraged to address both the approach in general and the specific technology assumed for the benchmark vehicles.
We are aware that in this approach, some of the projected technology packages would not provide a direct path to compliance for manufacturers, such as in the example above of the MHD Regional vehicle.  Using the technologies adopted at projected rates, it would fall short of the standard by 1.5 percent.  The agencies believe that the Phase 2 program has enough regulatory flexibility (averaging, banking, and trading provisions in particular) to enable such a vehicle to be certified.
In the package descriptions that follow, individual technology costs are not presented, rather these can be found in the draft RIA Chapter 2.9 and 2.12.  Section V. C. (2) (d) includes the costs estimated for packages of technologies the agencies project would enable vocational vehicles to meet the proposed Phase 2 standards.
Transmission Packages
The agencies project that 30 percent of vocational vehicles would have one or more of the transmission technologies identified above in this section applied by MY 2021, increasing to nearly 60 percent by MY 2024 and over 80 percent by MY 2027.  Most of this increase is due to a projected increase in adoption of technologies that represent deep driveline integration.  The agencies project an adoption rate of 15 percent in MY 2021 and 30 percent in MY 2024 for manufacturers using the powertrain test to be recognized for non-hardware upgrades such as gear efficiencies, shift strategies, and torque converter lockups, as well as other technologies that enable driveline optimization.  Due to the relatively high efficiency gains available from driveline optimization for relatively low costs, the agencies are projecting a 70 percent application rate of driveline optimization by MY 2027 across all subcategories.  We do not have information about the extent to which integration may be deterred by barriers to information-sharing between component suppliers.  Therefore we are projecting that major manufacturers would work to overcome these barriers, integrate and optimize their drivelines, and use the powertrain test on all eligible configurations, while smaller manufacturers may not adopt these technologies at all, or not to a degree that they would find value in this optional test procedure.
For the technology of adding two gears, we are predicating the proposed MY 2021 standard on a five percent adoption rate, except zero in the HHD Regional subcategory, which is modeled with a 10-speed transmission.  This adoption rate is projected to essentially remain at this level throughout the program, with an increase to ten percent only for two subcategories (Regional LHD and MHD) in MY 2027.  This is because the manufacturers most likely to develop 8-speed transmissions are those that are also developing transmissions for HD pickups and vans, and the GEM-certified vocational market share among those manufacturers is relatively small.
The HHD Regional subcategory is the only one where we assume a manual transmission in the baseline configuration.  For these vehicles, the agencies project upgrades to electronic transmissions such as either AMT, DCT, or automatic, at collective adoption rates of 51 percent in MY 2021, 68 percent in MY 2024, and five percent in MY 2027.  The decrease in MY 2027 reflects a projection that a greater number of deeply integrated HHD powertrains would be used by MY 2027 (one consequence being that fewer HHD powertrains would be directly simulated in GEM in that year).  The larger numbers in the phase-in years reflect powertrains that have been automated or electrified but not deeply integrated.  The agencies have been careful to account for the cost of both electrifying and deeply integrating the MY 2027 powertrains.  In draft RIA Chapter 11, the technology adoption rates for the HHD Regional subcategory presented in Table 11-42, Table 11-45, and Table 11-48 account for the assumption that a manual transmission cannot be deeply integrated, so there must also be an automation upgrade.  These tables are inputs to the agencies' cost analysis, thus the costs of both upgrading and integrating HHD powertrains are included.  The adoption rates of the upgraded but not integrated transmission architectures represent a projection of three percent of all vocational vehicles in MY 2021 and four percent in MY 2024.  This is based on an estimate that seven percent of the vocational vehicles would be in the HHD Regional subcategory.  For more information about the assumptions that were made about the populations of vehicles in different subcategories, see the agencies' inventory estimates in draft RIA Chapter 5.
In the eight subcategories in which automatic transmissions are the base technology, the agencies project that five percent would upgrade to a dual clutch transmission in MY 2021.  This projection increases to 15 percent in MY 2024 and decreases in MY 2027 to ten percent for two subcategories (Regional LHD and MHD) and five percent for the remaining 6 subcategories.  The low projected adoption rates of DCT reflect the fact that this is a relatively new technology for the heavy-duty sector, and it is likely that broader market acceptance would be achieved once fleets have gained experience with the technology.  Similar to the pattern described for the HHD Regional subcategory, the decrease in MY 2027 reflects a projection of greater use of deeply integrated powertrains.
In setting the proposed standard stringency, we have projected that hybrids on vehicles certified in the Multipurpose subcategories would achieve on average 22 percent improvement, and those in the Urban subcategories would see a 25 percent improvement.  We have also projected zero hybrid adoption rate by vehicles in the Regional subcategories, expecting that the benefit of hybrids for those vehicles would be too low to merit use of that type of technology.  However, there is no fixed hybrid value assigned in GEM and the actual improvement over the applicable test cycle would be determined by powertrain testing.  By the full implementation year of MY 2027, the agencies are projecting an overall vocational vehicle adoption rate of ten percent hybrids, which we estimate would be 18 percent of vehicles certified in the Multi-Purpose and Urban subcategories.  We are projecting a low adoption rate in the early years of the Phase 2 program, just four percent in these subcategories in MY 2021, and seven percent in MY 2024 for vehicles certified in the Multi-Purpose and Urban subcategories.  Based on our assumptions about the populations of vehicles in different subcategories, these hybrid adoption rates are about two percent overall in MY 2021 and four percent overall in MY 2024.
Considering the combination of the above technologies and adoption rates, we project the CO2 and fuel efficiency improvements for all transmission upgrades to be approximately seven percent on a fleet basis by MY 2027.  One subcategory in which we are projecting a very large advanced transmission adoption rate is the HHD Regional subcategory, in which we are projecting 75 percent of the transmissions would be either automated or automatic (upgraded from a manual) with 70 percent of those also being deeply integrated by MY 2027.  By comparison, the agencies are projecting that HHD day cab tractors would have 90 percent adoption of automated or automatic transmissions by MY 2027.  Although we are not prepared to predict what fraction of these would be upgraded in the absence of Phase 2, the draft RIA Chapter 2.9 explains why the agencies are confident that durable transmissions will be widely available in the Phase 2 time frame to support manufacture of HHD vocational vehicles.
If the above technologies do not reach the expected level of market adoption, the vocational vehicle Phase 2 program has several other technology options that manufacturers could choose to meet the proposed standards.
Axle Packages
The agencies project that 75 percent of vocational vehicles in all subcategories would adopt advanced axle lubricant formulations in all implementation years of the Phase 2 program.  Fuel efficient lubricant formulations are widespread across the heavy-duty market, though advanced synthetic formulations are currently less popular.  Axle lubricants with improved viscosity and efficiency-enhancing performance are projected to be widely adopted by manufacturers in the time frame of Phase 2.  Such formulations are commercially available and the agencies see no reason why they could not be feasible for most vehicles.  Nonetheless, we have refrained from projecting full adoption of this technology.  The agencies do not have specific information regarding reasons why axle manufacturers may specify a specific type of lubricant over another, and whether advanced lubricant formulations may not be recommended in all cases.  The agencies request comment on information regarding any vocational vehicle applications for which use of advanced lubricants would not be feasible.
The agencies estimate that 45 percent of HHD Regional vocational vehicles would adopt either full time or part time 6x2 axle technology in MY 2021.  This technology is most likely to be applied to Class 8 vocational vehicles (with 2 rear axles) that are designed for frequent highway trips.  The agencies project a slightly higher adoption rate of 60 percent combined for both full and part time 6x2 axle technologies in MY 2024 and MY 2027.  Based on our estimates of vehicle populations, this is about four percent of all vocational vehicles.
Tire Packages
The agencies estimate that the per-vehicle average level of rolling resistance from vocational vehicle tires could be reduced by 11 percent by full implementation of the Phase 2 program in MY 2027, based on the tire development achievements expected over the next decade.  This is estimated by weighting the projected improvements of steer tires and drive tires using an assumed axle load distribution of 30 percent on the steer tires and 70 percent on the drive tires, as explained in the draft RIA Chapter 2.9.  The projected adoption rates and expected improvements in CRR are presented in Table V-16.  By applying the assumed axle load distribution, the average vehicle CRR improvements projected for the proposed MY 2021 standards would be four percent, which we project would achieve up to one percent reduction in fuel use and CO2 emissions, depending on the vehicle subcategory.  Using that same method, the agencies estimate the average vehicle CRR in MY 2024 would be seven percent, yielding reductions in fuel use and CO2 emissions of between one and two percent, depending on the vehicle subcategory.
The agencies understand that the vocational vehicle segment has access to a large variety of tires, including some that are designed for tractors, some that are designed for HD pickups and vans, and some with multiple use designations.  In spite of the likely availability of LRR tires during the Phase 2 program, the projected adoption rates are intended to be conservative.  The agencies believe that these tire packages recognize the variety of tire purposes and performance levels in the vocational vehicle market, and maintain choices for manufacturers to use the most efficient tires (i.e. those with least rolling resistance) only where it makes sense given these vehicles' differing purposes and applications.
Table V-16 Projected LRR Tire Adoption Rates
Tire Position
Level of Rolling Resistance
MY 2021 Adoption Rate
MY 2024 Adoption Rate
MY 2027 Adoption Rate
Drive
Baseline CRR (7.7)
50
20
10
Steer
Baseline CRR (7.7)
20
10
0
Drive
5% Lower CRR (7.3)
50
50
25
Steer
10% Lower CRR (6.9)
80
30
20
Drive
10% Lower CRR (6.9)
0
30
50
Steer
15% Lower CRR (6.5)
0
60
30
Drive
15% Lower CRR (6.5)
0
0
15
Steer
20% Lower CRR (6.2)
0
0
50
Drive
Average Improvement in CRR
3%
6%
9%
Steer
Average Improvement in CRR
8%
12%
17%
For comparison purposes, the reader may note that these levels of tire CRR generally correspond with levels of tire CRR projected for tractors built for the Phase 1 standards.  For example, the baseline level CRR for vocational tires is very similar to the baseline tractor steer tire CRR.  Vocational vehicle tires with 10 percent better CRR have a similar CRR level as tractor tires of Drive Level 1. Vocational vehicle tires with 15 percent better CRR have a similar CRR level as tractor tires of Steer Level 1.  Vocational vehicle tires with 20 percent better CRR have a similar CRR level as tractor tires of Drive Level 2, as described in Section III.D.2.
Idle Reduction Packages
In this proposal, we are projecting a progression of idle reduction technology development that begins with 70 percent adoption rate of neutral idle for the MY 2021 standards, which by MY 2027 is replaced by a 70 percent adoption rate of stop-start idle reduction technology.  Although it is possible that a vehicle could have both neutral idle and stop-start, we are only considering emissions reductions for vehicles with one or the other of these technologies.  Also, as the program phases in, we do not see a reduction in the projected adoption rate of neutral idle to be a concern in terms of stranded investment, because it is a very low cost technology that could be an enabler for stop-start systems in some cases.
We are not projecting any adoption of neutral idle for the HHD Regional subcategory, because any vehicle with a manual transmission must shift to neutral when stopped to avoid stalling the engine, vehicles in the HHD Regional subcategory would already essentially be idling in neutral, and no additional technology would be needed to achieve this.  A similar case can be made for any vocational vehicle with an automated manual transmission, since these share inherently similar architectures with manuals.  The agencies are not projecting an adoption rate of 85 percent neutral idle until MY 2024, because it may take some additional development time to apply this technology to high-torque automatic transmissions designed for the largest vocational vehicles. Based on stakeholder input, the designs needed to avoid an uncomfortable re-engagement bump when returning to drive from neutral may require some engineering development time as well as some work to enable two-way communication between engines and transmissions.
We are projecting a five percent adoption rate of stop-start in the six MHD and LHD subcategories for MY 2021 and zero for the HHD vehicles, because this technology is still developing for vocational vehicles and is most likely to be feasible in the early years of Phase 2 for vehicles with lower power demands and lower engine inertia.  Stopping a heavy-duty engine is not challenging.  The real challenge is designing a robust system that can deliver multiple smooth restarts daily without loss of function while the engine is off.  Many current light-duty products offer this feature, and some heavy-duty manufacturers are exploring this.  The agencies are projecting an adoption rate of 15 percent stop-start across all subcategories in the intermediate year of MY 2024.  The agencies are projecting this technology to have a relatively high adoption rate (70 percent as stated above) by MY 2027 because we see it being technically feasible on the majority of vocational vehicles, and especially effective on those with the most time at idle in their workday operation.  Although we are not prepared to predict what fraction of vehicles would adopt stop-start in the absence of Phase 2, the draft RIA Chapter 2.9 explains why the agencies are confident that this technology, which is on the entry-level side of the hybrid and electrification spectrum, will be widely available in the Phase 2 time frame.
Based on these projected adoption rates and the effectiveness values described above in this section, we expect overall GHG and fuel consumption reductions from workday idle on vocational vehicles to be approximately three percent in MY 2027.
Weight Reduction Packages
As described in the draft RIA Chapter 2.12, weight reduction is a relatively costly technology, at approximately $3 to $4 per pound for a 200-lb package.  Even so, for vehicles in service classes where dense, heavy loads are frequently carried, weight reduction can translate directly to additional payload.  The agencies project weight reduction would most likely be used for vocational vehicles in the refuse and construction service classes, as well as some regional delivery vehicles.  The agencies are predicating the proposed standards on an adoption rate of five to eight percent, depending on the subcategory, in MY 2027, with slightly lower adoption rates in MY 2021 and MY 2024.
For this technology package, NHTSA and EPA project manufacturers would use material substitution in the amount of 200 pounds.  An example of how this weight could be reduced would be a complete set of aluminum wheels for a Class 8 vocational vehicle, or an aluminum transmission case plus high strength steel wheels, frame rails, and suspension brackets on a MHD or LHD vocational vehicle.  The agencies have limited information about how popular the use of aluminum components is in the vocational vehicle sector.  We request comments with information on whether any lightweight vocational vehicle components are in such widespread use that we should exclude them from the list of components for which a GEM improvement value would be available.
    GEM Inputs for Derivation of Proposed Vocational Vehicle Standards
To derive the stringency of the proposed vocational vehicle standards, the agencies developed a suite of fuel consumption maps for use with the GEM: one set of maps that represent engines meeting the proposed MY 2021 vocational diesel engine standards, a second set of maps representing engines meeting the proposed MY 2024 vocational diesel engine standards, and a third set of maps representing engines meeting the proposed MY 2027 vocational diesel engine standards.  By incorporating the engine technology packages projected to be adopted to meet the proposed Phase 2 vocational CI engine standards, the agencies employed GEM engine models in deriving the stringency of the proposed Phase 2 CI-powered vocational vehicle standards.  As noted above, because the agencies did not have enough information to develop a robust GEM-based gasoline engine fuel map, the stringency of the proposed SI-powered vocational vehicle standards is derived as an adjustment from the CI-powered vocational vehicle standards.  See the draft RIA Chapter 2.9 for more details about this adjustment process.
Depending on the particular technology, either the effectiveness was assigned by the agencies using an accepted average value, or the GEM tool was used to assess the proposed technology effectiveness, as discussed above. The agencies derived a scenario vehicle for each subcategory using the adoption rate and assigned or modeled improvement values of transmission, axle, and idle reduction technologies.  For example, the MY 2021 CRR values for each subcategory scenario case were derived as follows: for steer tires - 20 percent times 7.7 plus 80 percent times 6.9 yields an average CRR of 7.1 kg/metric ton; and for drive tires - 50 percent times 7.7 plus 50 percent times 7.3 yields an average CRR of 7.5 kg/metric ton.  Similar calculations were done for weight reduction, transmission improvements, and axle improvements.  The set of tire CRR, idle reduction, weight reduction, engine and transmission input parameters that was modeled in GEM in support of the proposed MY 2021 vocational vehicle standards is shown in Table V-17.  The agencies derived the level of the proposed MY 2024 standards by using the tire, weight reduction, engine and transmission GEM inputs shown in Table V-18, below.  The agencies derived the level of the proposed MY 2027 standards by using the tire, weight reduction, engine and transmission GEM inputs shown in Table V-19, below.  As post-processing, the respective adoption rates and assigned improvement values of transmission, axle, and idle reduction technologies were calculated for each subcategory.
The agencies have not directly transferred the GEM results from these inputs as the proposed standards.  Rather, the proposed standards are the result of the normalizing and benchmarking analysis described above. The proposed standards are presented in Table V-4 through Table V-9.  Additional detail is provided in the RIA Chapter 2.9.
Table V-17: GEM Inputs Used to Derive Proposed MY 2021 Vocational Vehicle Standards
                                  Class 2b-5
                                   Class 6-7
                                    Class 8
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                 CI Engine[a]
                           2021 MY 7L, 200 hp Engine
                           2021 MY 7L, 270 hp Engine
                          2021 MY 11L, 345 hp Engine
                           2021 MY 15L 455hp Engine
                       Transmission (improvement factor)
                                     0.023
                                     0.021
                                     0.008
                                     0.023
                                     0.021
                                     0.009
                                     0.023
                                     0.022
                                     0.022
                           Axle (improvement factor)
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.012
                          Stop-Start (adoption rate)
                                      5%
                                      5%
                                      5%
                                      5%
                                      5%
                                      5%
                                      0%
                                      0%
                                      0%
                         Neutral Idle (adoption rate)
                                      70%
                                      70%
                                      70%
                                      70%
                                      70%
                                      70%
                                      70%
                                      70%
                                      0%
                        Steer Tires (CRR kg/metric ton)
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                        Drive Tires (CRR kg/metric ton)
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                             Weight Reduction (lb)
                                       8
                                       8
                                      14
                                       8
                                       8
                                      12
                                       8
                                       8
                                      10
Note:
[a] SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results

Table V-18: GEM Inputs Used to Derive Proposed MY 2024 Vocational Vehicle Standards
                                  Class 2b-5
                                   Class 6-7
                                    Class 8
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                 CI Engine[a]
                           2024 MY 7L, 200 hp Engine
                           2024 MY 7L, 270 hp Engine
                          2024 MY 11L, 345 hp Engine
                           2024 MY 15L 455hp Engine
                       Transmission (improvement factor)
                                     0.045
                                     0.04
                                     0.017
                                     0.045
                                     0.041
                                     0.018
                                     0.045
                                     0.042
                                     0.035
                           Axle (improvement factor)
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.014
                          Stop-Start (adoption rate)
                                      15%
                                      15%
                                      15%
                                      15%
                                      15%
                                      15%
                                      15%
                                      15%
                                      15%
                         Neutral Idle (adoption rate)
                                      85%
                                      85%
                                      85%
                                      85%
                                      85%
                                      85%
                                      85%
                                      85%
                                      0%
                        Steer Tires (CRR kg/metric ton)
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                                      6.8
                        Drive Tires (CRR kg/metric ton)
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                                      7.3
                             Weight Reduction (lb)
                                       8
                                       8
                                      14
                                       8
                                       8
                                      12
                                       8
                                       8
                                      10
Note:
[a] SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results

Table V-19: GEM Inputs Used to Derive Proposed MY 2027 Vocational Vehicle Standards
                                  Class 2b-5
                                   Class 6-7
                                    Class 8
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                 CI Engine[a]
                           2027 MY 7L, 200 hp Engine
                           2027 MY 7L, 270 hp Engine
                          2027 MY 11L, 345 hp Engine
                           2027 MY 15L 455hp Engine
                       Transmission (improvement factor)
                                     0.096
                                     0.085
                                     0.034
                                     0.096
                                     0.088
                                     0.037
                                     0.097
                                     0.089
                                     0.036
                           Axle (improvement factor)
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.014
                          Stop-Start (adoption rate)
                                      75%
                                      70%
                                      70%
                                      75%
                                      70%
                                      70%
                                      70%
                                      70%
                                      70%
                         Neutral Idle (adoption rate)
                                      25%
                                      30%
                                      30%
                                      25%
                                      30%
                                      30%
                                      30%
                                      30%
                                      0%
                        Steer Tires (CRR kg/metric ton)
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                                      6.4
                        Drive Tires (CRR kg/metric ton)
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                                      7.0
                             Weight Reduction (lb)
                                      10
                                      10
                                      16
                                      10
                                      10
                                      14
                                      10
                                      10
                                      12
Note:
[a] SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results
    Technology Package Costs
The agencies have estimated the costs of the technologies that could be used to comply with the proposed standards.  The estimated costs are shown in Table V-20 for MY2021, in Table V-21 for MY2024, and Table V-22 for MY 2027.  Fleet average costs are shown for light, medium and heavy HD vocational vehicles in each duty-cycle-based subcategory  -  Urban, Multi-Purpose, and Regional.  As shown in Table V-20, in MY 2021 these range from approximately $600 for MHD and LHD Regional vehicles, up to $3,400 for HHD Regional vehicles.  Those two lower-cost packages reflect zero hybrids, and the higher-cost package reflects significant adoption of automated transmissions.   In the draft RIA Chapter 2.13.2, the agencies present vocational vehicle technology package costs differentiated by MOVES vehicle type.  For example, intercity buses are estimated to have an average package cost of $2,900 and gasoline motor homes are estimated to have an average package cost of $450 in MY 2021.  These costs do not indicate the per-vehicle cost that may be incurred for any individual technology.  For more specific information about the agencies' estimates of per-vehicle costs, please see the draft RIA Chapter 2.12.  For example, Chapter 2.12.7 describes why a complex technology such as hybridization is estimated to range between $15,000 and $40,000 per vehicle for vocational vehicles in MY 2021.  The engine costs listed represent the cost of an average package of diesel engine technologies.  Individual technology adoption rates for engine packages are described in Section II.D.  The details behind all these costs are presented in draft RIA Chapter 2.12, including the markups and learning effects applied and how the costs shown here are weighted to generate an overall cost for the vocational segment.
Table V-20:  Vocational Vehicle Technology Incremental Costs for the Proposal in the 2021 Model Year[a,b] (2012$)

Light HD
Medium HD
Heavy HD

Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Engine[c]
                                                                           $293
                                                                           $293
                                                                           $293
                                                                           $270
                                                                           $270
                                                                           $270
                                                                           $270
                                                                           $270
                                                                           $270
Tires
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
Transmission
                                                                            $81
                                                                            $81
                                                                            $81
                                                                            $81
                                                                            $81
                                                                            $81
                                                                            $81
                                                                            $81
                                                                         $2,852
Axle related
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                           $148
                                                                           $148
                                                                           $219
Weight Reduction
                                                                            $27
                                                                            $27
                                                                            $48
                                                                            $27
                                                                            $27
                                                                            $41
                                                                            $27
                                                                            $27
                                                                            $34
Idle reduction
                                                                            $49
                                                                            $49
                                                                            $49
                                                                            $51
                                                                            $51
                                                                            $51
                                                                             $6
                                                                             $6
                                                                             $0
Electrification & hybridization
                                                                           $547
                                                                           $547
                                                                             $0
                                                                           $861
                                                                           $861
                                                                             $0
                                                                         $1,437
                                                                         $1,437
                                                                             $0
Air Conditioning[d]
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
Total
                                                                         $1,125
                                                                         $1,125
                                                                           $598
                                                                         $1,418
                                                                         $1,418
                                                                           $571
                                                                         $1,998
                                                                         $1,998
                                                                         $3,404
Notes:
[a] Costs shown are for the 2021 model year and are incremental to the costs of a vehicle meeting the Phase 1 standards. These costs include indirect costs via markups along with learning impacts.  For a description of the markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).
[b] Note that values in this table include adoption rates.  Therefore, the technology costs shown reflect the average cost expected for each of the indicated vehicle classes.  To see the actual estimated technology costs exclusive of adoption rates, refer to Chapter 2 of the draft RIA (see RIA 2.9 in particular).
[c] Engine costs are for a light HD, medium HD or heavy HD diesel engine. We are projecting no additional costs beyond Phase 1 for gasoline vocational engines.
[d] EPA's air conditioning standards are presented in Section V.C above.

The estimated fleet average vocational vehicle package costs are shown in Table V-21 for MY2024.  As shown, these range from approximately $800 for MHD and LHD Regional vehicles, up to $4,800 for HHD Regional vehicles.  The increased costs above the MY 2021 values reflect increased adoption rates of individual technologies, while the individual technology costs are generally expected to remain the same or decrease, as explained in the draft RIA Chapter 2.12.  For example, Chapter 2.12.7 presents MY 2024 hybridization costs that range from $13,000 to $33,000 per vehicle for vocational vehicles.  The engine costs listed represent the average costs associated with the proposed MY 2024 vocational diesel engine standard described in Section II.D.

Table V-21:  Vocational Vehicle Technology Incremental Costs for the Proposal in the 2024 Model Year[a][,b] (2012$)

Light HD
Medium HD
Heavy HD

Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Engine[c]
                                                                           $437
                                                                           $437
                                                                           $437
                                                                           $405
                                                                           $405
                                                                           $405
                                                                           $405
                                                                           $405
                                                                           $405
Tires
                                                                            $17
                                                                            $17
                                                                            $17
                                                                            $17
                                                                            $17
                                                                            $17
                                                                            $23
                                                                            $23
                                                                            $23
Transmission
                                                                           $123
                                                                           $123
                                                                           $123
                                                                           $123
                                                                           $123
                                                                           $123
                                                                           $123
                                                                           $123
                                                                         $3,915
Axle related
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                           $136
                                                                           $136
                                                                           $224
Weight Reduction
                                                                            $24
                                                                            $24
                                                                            $43
                                                                            $24
                                                                            $24
                                                                            $37
                                                                            $24
                                                                            $24
                                                                            $30
Idle reduction
                                                                           $119
                                                                           $119
                                                                           $119
                                                                           $125
                                                                           $125
                                                                           $125
                                                                           $224
                                                                           $224
                                                                           $217
Electrification & hybridization
                                                                           $906
                                                                           $906
                                                                             $0
                                                                         $1,423
                                                                         $1,423
                                                                             $0
                                                                         $2,377
                                                                         $2,377
                                                                             $0
Air Conditioning[d]
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
Total
                                                                         $1,737
                                                                         $1,737
                                                                           $849
                                                                         $2,228
                                                                         $2,228
                                                                           $817
                                                                         $3,332
                                                                         $3,332
                                                                         $4,834
Notes:
[a] Costs shown are for the 2024 model year and are incremental to the costs of a vehicle meeting the Phase 1 standards. These costs include indirect costs via markups along with learning impacts.  For a description of the markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).
[b] Note that values in this table include adoption rates.  Therefore, the technology costs shown reflect the average cost expected for each of the indicated vehicle classes.  To see the actual estimated technology costs exclusive of adoption rates, refer to Chapter 2 of the draft RIA (see RIA 2.9 in particular).
[c] Engine costs are for a light HD, medium HD or heavy HD diesel engine. We are projecting no additional costs beyond Phase 1 for gasoline vocational engines.
[d] EPA's air conditioning standards are presented in Section V.C above.

The estimated fleet average vocational vehicle package costs are shown in Table V-22 for MY2027.  As shown, these range from approximately $1,400 for MHD and LHD Regional vehicles, up to $7,400 for HHD Urban and Multipurpose vehicles.  These two subcategories are projected to have the higher-cost packages in MY 2027 due to an estimated 18 percent adoption of HHD hybrids, which are estimated to cost $31,000 per vehicle in MY 2027, as shown in Chapter 2.12.7 of the draft RIA.   These per-vehicle technology package costs were averaged using our projections of vehicle populations in the nine regulatory subcategories and do not correspond to the MOVES vehicle types.  The engine costs shown represent the average costs associated with the proposed MY 2027 vocational diesel engine standard described in Section II.D.  For gasoline vocational vehicles, the agencies are projecting adoption of Level 2 engine friction reduction with an estimated $68 added to the average SI vocational vehicle package cost in MY 2027, which represents about 56 percent of those vehicles upgrading beyond Level 1 engine friction reduction.  Further details on how these SI vocational vehicle costs were estimated are provided in the draft RIA Chapter 2.9.
Purchase prices of vocational vehicles can range from $60,000 for a stake-bed landscape truck to over $400,000 for some transit buses.  The costs of the vocational vehicle standards can be put into perspective by considering package costs estimated using MOVES vehicle types along with typical prices for those vehicles.  For example, a package cost of $4,000 on a $60,000 short haul straight truck would represent an incremental increase of about six percent of the vehicle purchase price.  Similarly, a package cost of $7,000 on a $200,000 refuse truck would represent an incremental increase of less than four percent of the vehicle purchase price.  The vocational vehicle industry characterization report in the docket includes additional examples of vehicle prices for a variety of vocational applications.
Table V-22:  Vocational Vehicle Technology Incremental Costs for the Proposal in the 2027 Model Year[a][,b] (2012$)

Light HD
Medium HD
Heavy HD

Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Engine[c]
                                                                           $471
                                                                           $471
                                                                           $471
                                                                           $437
                                                                           $437
                                                                           $437
                                                                           $437
                                                                           $437
                                                                           $437
Tires
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $29
                                                                            $29
                                                                            $29
Transmission
                                                                           $244
                                                                           $244
                                                                           $267
                                                                           $244
                                                                           $244
                                                                           $267
                                                                           $244
                                                                           $244
                                                                         $2,986
Axle related
                                                                            $86
                                                                            $86
                                                                            $86
                                                                            $86
                                                                            $86
                                                                            $86
                                                                           $129
                                                                           $129
                                                                           $215
Weight Reduction
                                                                            $29
                                                                            $29
                                                                            $46
                                                                            $29
                                                                            $29
                                                                            $40
                                                                            $29
                                                                            $29
                                                                            $35
Idle reduction
                                                                           $498
                                                                           $499
                                                                           $499
                                                                           $526
                                                                           $526
                                                                           $526
                                                                           $964
                                                                           $964
                                                                           $962
Electrification & hybridization
                                                                         $2,122
                                                                         $2,122
                                                                             $0
                                                                         $3,336
                                                                         $3,336
                                                                             $0
                                                                         $5,571
                                                                         $5,571
                                                                             $0
Air Conditioning[d]
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
                                                                            $19
Total
                                                                         $3,489
                                                                         $3,490
                                                                         $1,407
                                                                         $4,696
                                                                         $4,696
                                                                         $1,395
                                                                         $7,422
                                                                         $7,422
                                                                         $4,682
Notes:
[a] Costs shown are for the 2027 model year and are incremental to the costs of a vehicle meeting the Phase 1 standards. These costs include indirect costs via markups along with learning impacts.  For a description of the markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).
[b] Note that values in this table include adoption rates.  Therefore, the technology costs shown reflect the average cost expected for each of the indicated vehicle classes.  To see the actual estimated technology costs exclusive of adoption rates, refer to Chapter 2 of the draft RIA (see RIA 2.9 in particular).
[c] Engine costs are shown for a light HD, medium HD or heavy HD diesel engine. For gasoline-powered vocational vehicles we are projecting $68 of additional engine-based costs beyond Phase 1.
[d] EPA's air conditioning standards are presented in Section V.C above.

Consistency of the Proposed Vocational Vehicle Standards with the Agencies' Legal Authority
NHTSA and EPA project the proposed standards to be achievable within known design cycles, and we believe these standards, although technology-forcing, would allow many different paths to compliance in addition to the example outlined in this section.  The proposed standards are predicated on manufacturers implementing technologies that we expect will be available in the time frame of these proposed rules, although in some instances these technologies are still under development or not widely deployed in the current vocational vehicle fleet.  Under the proposal, manufacturers would need to apply a range of technologies to their vocational chassis, which the agencies believe would consistent with the agencies' respective statutory authorities.  We are projecting that most vehicles could adopt certain of the technologies.  For example, we project a 70 to 75 percent application rate for stop-start idle reduction and advanced axle lubrication.  However, for other technologies, such as strong hybrids and weight reduction, we are projecting adoption rates of ten percent or less overall, with individual subcategories having adoption rates greater or less than this.  The proposed standards offer manufacturers the flexibility to apply the technologies that make sense for their business and customer needs.
As discussed above, average per-vehicle costs associated with the proposed 2027 MY standards are projected to be generally less than six percent of the overall price of a new vehicle.  The cost-effectiveness of these proposed vocational vehicle standards in dollars per ton is similar to the cost effectiveness estimated for light-duty trucks in the 2017-2025 light duty greenhouse gas standards, which the agencies have found to be highly cost effective.  In addition, the vocational vehicle standards are clearly effective from a net benefits perspective (see draft RIA Chapter 11.2).  Therefore, the agencies regard the cost of the proposed standards as reasonable.
The agencies note that while the projected costs are significantly greater than the costs projected for Phase 1, we still consider these costs to be reasonable, especially given that the first vehicle owner may see the technologies pay for themselves in many cases.  As discussed above, the usual period of ownership for a vocational vehicle reflects a lengthy trade cycle that may often exceed seven years.  For most vehicle types evaluated, the cost of these technologies, if passed on fully to customers, would be recovered within five years or less due to the associated fuel savings, as shown in the payback analysis included in Section IX and in the draft RIA Chapter 7.1.  Specifically, in Table 7-30 of the draft RIA Chapter 7.1.3, a summary is presented with estimated payback periods for each of the MOVES vocational vehicle types, using the annual vehicle miles traveled from the MOVES model for each vehicle type.  As shown, the vocational vehicle type with the shortest payback would be intercity buses (less than one year), while most other vehicles (with the exception of school buses and motor homes) are projected to see paybacks in the fifth year or sooner.
The agencies note further that although the proposal is technology-forcing (especially with respect to driveline improvements) and the estimated costs for each subcategory vary considerably (by a factor of five in some cases), these costs represent only one of many possible pathways to compliance for manufacturers.  Manufacturers retain leeway to develop alternative compliance paths, increasing the likelihood of the standards' successful implementation.  Based on available information, the agencies believe the proposed standards are technically feasible within the lead time provided, are cost effective while accounting for the fuel savings (see draft RIA Chapter 7.1.4), and have no apparent adverse collateral potential impacts (e.g., there are no projected negative impacts on safety or vehicle utility).
The proposed standards thus appear to represent a reasonable choice under Section 202(a) of the CAA and the maximum feasible under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).  The agencies believe that the proposed standards are consistent with their respective authorities.  Based on the information currently before the agencies, we believe that the preferred alternative would be maximum feasible and reasonable for the vocational segment with a progression of standards reaching full implementation in MY 2027.
Nevertheless, as discussed in Section V. D. (1) and in Section X (Alternatives), the agencies seek comment on the feasibility of Alternative 4 , which the agencies may determine is maximum feasible and reasonable depending on comments and information received during the comment period.  This alternative is discussed in detail below because it may be possible for manufacturers to accelerate product development cycles enough to reach the required levels by the 2024 model year.  Thus, the agencies may conclude in the final rules that Alternative 4, or some elements of this alternative, would be maximum feasible and appropriate under CAA section 202 (a)(1) and (2), depending on information and comments received.  The agencies seek comments to assist us in making that determination.
Alternative Vocational Vehicle Standards Considered
The agencies have analyzed vocational vehicle standards other than the proposed standards.  These alternatives, listed in Table III-22, are described in detail in Section X of this preamble and the draft RIA Chapter 11.  Below the agencies present a detailed analysis of the vocational vehicle alternative referred to as Alternative 4.
Table V-23: Summary of Alternatives Considered for the Proposed Rulemaking
Alternative 1
No action alternative
Alternative 2
Less stringent than the proposed alternative, applying off-the-shelf technologies
Alternative 3
(Proposed Alternative)
Proposed alternative fully phased-in by MY 2027
Alternative 4
Same stringency as proposed alternative, except phasing in faster, by MY 2024
Alternative 5
More stringent alternative, based on higher adoption rates of advanced technologies
         Feasibility of Alternative 4
NHTSA and EPA are considering an Alternative 4 that achieves the same level of stringency as the preferred alternative, except it would provide less lead time, reaching its most stringent level three years earlier than the preferred alternative, that is in MY 2024.  The agencies project that the same selection of technology options would be available to manufacturers regardless of what alternative is chosen.  The preferred alternative would allow greater lead time to manufacturers to select and develop technologies for their vehicles.
The agencies have outstanding questions regarding relative risks and benefits of Alternative 4 due to the time frame envisioned by that alternative.  If the agencies receive relevant information supporting the feasibility of Alternative 4, the agencies may consider establishing vocational vehicle standards that provide more overall reductions than what we are proposing if we deem them to be maximum feasible and reasonable for NHTSA and EPA, respectively.  See the draft RIA Chapter 11.2.2 for a summary of costs and benefits that compares the proposed Phase 2 vocational vehicle program with the costs and benefits of other vocational vehicle alternatives considered.
In the paragraphs that follow, the agencies present the derivation of the Alternative 4 vocational vehicle standards.  For currently developing technologies where we project an adoption rate that could present potential risks or challenges, we seek comment on the cost and effectiveness of such technology.  Further, the agencies seek comment on the potential for adoption of developing technologies into the vocational vehicle fleet, as well as the extent to which the more accelerated alternative vocational vehicle standards may depend on such technology.
    Adoption Rates for Derivation of Alternative 4 Vocational Vehicle Standards
In developing the Alternative 4 standards, the agencies are projecting a set of technology packages in MY 2024 that is identical to those projected for the final phase-in year of the preferred alternative.  Because these are the same for each subcategory, the GEM inputs modeled to derive the level of the MY 2024 Alternative 4 standards can be found in Table V-19, which presents the GEM inputs used to derive the level of the MY 2027 proposed standards.  In the package descriptions below, the agencies outline technology-specific adoption rates in MY 2021 for Alternative 4 and offer insights on what market conditions could enable reaching adoption rates that would achieve the full implementation levels of stringency with less lead time.
For transmissions including hybrids, the agencies project for Alternative 4 that 50 percent of vocational vehicles would have one or more of the transmission technologies identified above in this section applied by MY 2021.  This includes 25 percent deeply integrated conventional transmissions that would be recognized over the powertrain test, 10 percent DCT, 11 percent adding two gears (except zero for HHD Regional), and nine percent hybrids for vehicles certified in the Multi-Purpose and Urban subcategories, which we estimate would be five percent overall.  In this alternative, the agencies project 21 percent of the vocational vehicles with manual transmissions in the HHD Regional subcategory would upgrade to either an AMT, DCT, or automatic transmission.  The increased projection of driveline integration would mean that more manufacturers would need to overcome data-sharing barriers.  In this alternative, we project that manufacturers would need to conduct additional research and development to achieve overall application of five percent hybrids.  In the draft RIA Chapter 7.1, the agencies have estimated costs for this additional accelerated research. Comments are requested on the expected costs to accelerate hybrid development to meet the projected adoption rates of this alternative.
For advanced axle lubricants, the agencies are projecting the same 75 percent adoption rate in MY 2021 as in the proposed program.  For part time or full time 6x2 axles, the agencies project the HHD Regional vocational vehicles could apply this at the 60 percent adoption rate in MY 2021, where this level wouldn't be reached until MY 2024 in the proposed program. One action that could enable this to be achieved is if information on the reliability of these systems were to be disseminated to more fleet owners by trustworthy sources.
For lower rolling resistance tires in this alternative, the agencies project the same adoption rates of LRR tires as in the proposed program for MY 2021, because we don't expect tire suppliers would be able to make greater improvements for the models that are fitted on vocational vehicles in that time frame.  The tire research that is being conducted currently is focused on models for tractors and trailers, and we project further improved LRR tires would not be commercially available for vocational vehicles in the early implementation years of Phase 2.
For the adoption rate of LRR tires in MY 2024 to reach the level projected for MY 2027 in the proposed program, tire suppliers could promote their most efficient products to vocational vehicle manufacturers to achieve equivalent improvements with less lead time.  Depending on how tire manufacturers focus their research and product development, it is possible that more of the LRR tire advancements being applied for tractors and trailers could be applied to vocational vehicles. To see the specific projected adoption rates of different levels of LRR tires for Alternative 4, see columns three and five of Table V-16 above.
For workday idle technologies, the agencies project an adoption rate of 12 percent stop-start in the six MHD and LHD subcategories for MY 2021 and zero for the HHD vehicles, on the expectation that manufacturers would have fewer challenges in the short term in bringing this technology to market for vehicles with lower power demands and lower engine inertia.  In this alternative, the agencies project the overall workday idle adoption rate would approach 100 percent, such that any vehicle without stop-start (except HHD Regional) would apply neutral idle in MY 2021.  These adoption raters consider a more aggressive investment by manufacturers in developing these technologies.  Estimates of research and development costs for this alternative are presented in the draft RIA Chapter 7.1.
For weight reduction, in this alternative, the agencies project the same adoption rates of a 200-lb lightweighting package as in the proposal for each subcategory in MY 2021, which is four to seven percent.
Table V-24 shows the GEM inputs used to derive the level of the Alternative 4 MY 2021 standards.
Table V-24: GEM Inputs Used to Derive Alternative 4 MY 2021 Vocational Vehicle Standards
                                  Class 2b-5
                                   Class 6-7
                                    Class 8
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                                     Urban
                                 Multi-Purpose
                                   Regional
                          Alternative 4 CI Engine[a]
                           2021 MY 7L, 200 hp Engine
                           2021 MY 7L, 270 hp Engine
                          2021 MY 11L, 345 hp Engine
                           2021 MY 15L 455hp Engine
                       Transmission (improvement factor)
                                     0.045
                                     0.04
                                     0.014
                                     0.045
                                     0.041
                                     0.015
                                     0.045
                                     0.041
                                     0.018
                           Axle (improvement factor)
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.004
                                     0.015
                          Stop-Start (adoption rate)
                                      12%
                                      12%
                                      12%
                                      12%
                                      12%
                                      12%
                                      0%
                                      0%
                                      0%
                         Neutral Idle (adoption rate)
                                      88%
                                      88%
                                      88%
                                      88%
                                      88%
                                      88%
                                      90%
                                      90%
                                      0%
                        Steer Tires (CRR kg/metric ton)
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                                      7.1
                        Drive Tires (CRR kg/metric ton)
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                                      7.5
                             Weight Reduction (lb)
                                       8
                                       8
                                      14
                                       8
                                       8
                                      12
                                       8
                                       8
                                      10
Note:
[a] SI engines were not simulated in GEM, rather a gas/diesel adjustment factor was applied to the results.
    Possible Alternative 4 Standards
Because the MY 2024 Alternative 4 standards are the same as the proposed standards for MY 2027 for each subcategory, these numerical standards can be found in Table V-8 and Table V-9, which present EPA's and NHTSA's proposed MY 2027 standards, respectively.  Table V-25 and Table V-26 present the Alternative 4 vocational vehicle standards for the initial year of MY 2021.  These represent incremental improvements over the MY 2017 baseline of six to seven percent for SI-powered vocational vehicles and nine percent for CI-powered vocational vehicles.
Table V-25: Alternative 4 EPA CO2 Standards for MY2021 Class 2b-8 Vocational Vehicles
Alternative EPA Standard for Vehicle with CI Engine Effective MY2021 (gram CO2/ton-mile)
Duty Cycle
Light Heavy-Duty
Class 2b-5
Medium Heavy-Duty Class 6-7
Heavy Heavy-Duty
Class 8
Urban
288
183
193
Multi-Purpose
297
185
196
Regional
309
181
185
Alternative EPA Standard for Vehicle with SI Engine Effective MY2021 (gram CO2/ton-mile)
Duty Cycle
Light Heavy-Duty
Class 2b-5
Medium Heavy-Duty Class 6-7
Heavy Heavy-Duty
Class 8
Urban
313
199
210
Multi-Purpose
323
201
212
Regional
336
197
201

Table V-26: Alternative 4 NHTSA Fuel Consumption Standards for MY2021 Class 2b-8 Vocational Vehicles
Alternative NHTSA Standard for Vehicle with CI Engine Effective MY 2021 (Fuel Consumption gallon per 1,000 ton-mile)
Duty Cycle
Light Heavy-Duty
Class 2b-5
Medium Heavy-Duty Class 6-7
Heavy Heavy-Duty
Class 8
Urban
28.3890
17.9764
18.8605
Multi-Purpose
29.0766
18.0747
18.9587
Regional
30.1572
17.6817
17.9764
Alternative NHTSA Standard for Vehicle with SI Engine Effective MY 2021 (Fuel Consumption gallon per 1,000 ton-mile)
Duty Cycle
Light Heavy-Duty
Class 2b-5
Medium Heavy-Duty Class 6-7
Heavy Heavy-Duty
Class 8
Urban
35.2200
22.3923
23.6300
Multi-Purpose
36.3452
22.6173
23.8551
Regional
37.8080
22.1672
22.6173
    Costs Associated with Alternative 4 Standards
The agencies have estimated the costs of the technologies expected to be used to comply with the Alternative 4 standards, as shown in Table V-27 for MY2021.  Fleet average costs are shown for light, medium and heavy HD vocational vehicles in each duty-cycle-based subcategory  -  Urban, Multi-Purpose, and Regional.  As shown in Table V-27, in MY 2021 these range from approximately $800 for MHD and LHD Regional vehicles, to $4,300 for HHD Urban and Multipurpose vehicles.  Those two subcategories are projected to have the higher-cost packages in MY 2021 due to an estimated 9 percent adoption of HHD hybrids, which are estimated to cost $40,000 per vehicle in MY 2021, as shown in Chapter 2.12.7 of the draft RIA. For more specific information about the agencies' estimates of per-vehicle costs, please see the draft RIA Chapter 2.12.  The engine costs listed represent the cost of an average package of diesel engine technologies with Alternative 4 adoption rates described in Section II.D.2(e).  The details behind all these costs are presented in draft RIA Chapter 2.12, including the markups and learning effects applied and how the costs shown here are weighted to generate an overall cost for the vocational segment.
Table V-27 Vocational Vehicle Technology Incremental Costs for Alternative 4 Standards in the 2021 Model Year[a,b] (2012$)

Light HD
Medium HD
Heavy HD

Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Engine[c]
                                                                           $372
                                                                           $372
                                                                           $372
                                                                           $345
                                                                           $345
                                                                           $345
                                                                           $345
                                                                           $345
                                                                           $345
Tires
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
                                                                             $7
Transmission
                                                                           $148
                                                                           $148
                                                                           $148
                                                                           $148
                                                                           $148
                                                                           $148
                                                                           $148
                                                                           $148
                                                                         $2,042
Axle related
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                            $99
                                                                           $148
                                                                           $148
                                                                           $243
Weight Reduction
                                                                            $27
                                                                            $27
                                                                            $48
                                                                            $27
                                                                            $27
                                                                            $41
                                                                            $27
                                                                            $27
                                                                            $34
Idle reduction
                                                                           $110
                                                                           $110
                                                                           $110
                                                                           $116
                                                                           $116
                                                                           $116
                                                                             $8
                                                                             $8
                                                                             $0
Electrification & hybridization
                                                                         $1,384
                                                                         $1,384
                                                                             $0
                                                                         $2,175
                                                                         $2,175
                                                                             $0
                                                                         $3,633
                                                                         $3,633
                                                                             $0
Air Conditioning[d]
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
                                                                            $22
Total
                                                                         $2,169
                                                                         $2,169
                                                                           $805
                                                                         $2,938
                                                                         $2,938
                                                                           $777
                                                                         $4,337
                                                                         $4,337
                                                                         $2,693
Notes:
[a] Costs shown are for the 2021 model year and are incremental to the costs of a vehicle meeting the Phase 1 standards. These costs include indirect costs via markups along with learning impacts.  For a description of the markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).
[b] Note that values in this table include adoption rates.  Therefore, the technology costs shown reflect the average cost expected for each of the indicated vehicle classes.  To see the actual estimated technology costs exclusive of adoption rates, refer to Chapter 2 of the draft RIA (see RIA 2.9 in particular).
[c] Engine costs are for a light HD, medium HD or heavy HD diesel engine. We are projecting no additional costs beyond Phase 1 for gasoline vocational engines.
[d] EPA's air conditioning standards are presented in Section V.C above.
The estimated costs of the technologies expected to be used to comply with the Alternative 4 standards for MY2024 are shown in Table V-28.  As shown, these range from approximately $1,500 for MHD and LHD Regional vehicles to $7,900 for HHD Urban and Multipurpose vehicles.  These two subcategories are projected to have the higher-cost packages in MY 2024 due to an estimated 18 percent adoption of HHD hybrids, which are estimated to cost $33,000 per vehicle in MY 2024, as shown in Chapter 2.12.7 of the draft RIA.  The engine costs listed represent the cost of an average package of diesel engine technologies with Alternative 4 adoption rates described in Section II.D.2(e).  For gasoline vocational vehicles, the agencies are projecting adoption of Level 2 engine friction reduction with an estimated $74 added to the average SI vocational vehicle package cost in MY 2024, which represents about 56 percent of those vehicles upgrading beyond Level 1 engine friction reduction.  Further details on how these SI vocational vehicle costs were estimated are provided in the draft RIA Chapter 2.9.
Table V-28:  Vocational Vehicle Technology Incremental Costs for Alternative 4 Standards in the 2024 Model Year[a] (2012$)

Light HD
Medium HD
Heavy HD

Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Urban
Multi-
purpose
Regional
Engine[c]
                                                                           $493
                                                                           $493
                                                                           $493
                                                                           $457
                                                                           $457
                                                                           $457
                                                                           $457
                                                                           $457
                                                                           $457
Tires
                                                                            $26
                                                                            $26
                                                                            $26
                                                                            $26
                                                                            $26
                                                                            $26
                                                                            $40
                                                                            $40
                                                                            $40
Transmission
                                                                           $256
                                                                           $256
                                                                           $280
                                                                           $256
                                                                           $256
                                                                           $280
                                                                           $256
                                                                           $256
                                                                         $3,123
Axle related
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                            $90
                                                                           $136
                                                                           $136
                                                                           $224
Weight Reduction
                                                                            $30
                                                                            $30
                                                                            $49
                                                                            $30
                                                                            $30
                                                                            $43
                                                                            $30
                                                                            $30
                                                                            $37
Idle reduction
                                                                           $561
                                                                           $524
                                                                           $524
                                                                           $592
                                                                           $553
                                                                           $553
                                                                         $1,014
                                                                         $1,014
                                                                         $1,011
Electrification & hybridization
                                                                         $2,264
                                                                         $2,264
                                                                             $0
                                                                         $3,559
                                                                         $3,559
                                                                             $0
                                                                         $5,943
                                                                         $5,943
                                                                             $0
Air Conditioning[d]
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
                                                                            $20
Total
                                                                         $3,741
                                                                         $3,704
                                                                         $1,482
                                                                         $5,030
                                                                         $4,992
                                                                         $1,469
                                                                         $7,895
                                                                         $7,895
                                                                         $4,912
Notes:
[a] Costs shown are for the 2024 model year and are incremental to the costs of a vehicle meeting the Phase 1 standards. These costs include indirect costs via markups along with learning impacts. For a description of the markups and learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the draft RIA (see draft RIA 2.12).
[b] Note that values in this table include adoption rates. Therefore, the technology costs shown reflect the average cost expected for each of the indicated vehicle classes. To see the actual estimated technology costs exclusive of adoption rates, refer to Chapter 2 of the draft RIA (see RIA 2.9 in particular).
[c] Engine costs shown are for a light HD, medium HD or heavy HD diesel engine. For gasoline-powered vocational vehicles we are projecting $74 of additional engine-based costs beyond Phase 1.
[d] EPA's air conditioning standards are presented in Section V.C above.
Compliance Provisions for Vocational Vehicles
We welcome comment on all aspects of the compliance program, including those where we would adopt a provision without change in Phase 2.
Application and Certification Process
The agencies propose to continue to use GEM to determine compliance with the proposed vehicle fuel efficiency and CO2 standards.  Because the agencies are proposing to modify GEM to recognize inputs in addition to those recognized under Phase 1, there is a consequent proposed requirement that manufacturers or component suppliers conduct component testing to generate those input values. See Section II for details of engine testing and GEM inputs for engines.
As described above in Section I, the agencies propose to continue the Phase 1 compliance process in terms of the manufacturer requirements prior to the effective model year, during the model year, and after the model year.  The information that would be required to be submitted by manufacturers is set forth in 40 CFR 1037.205 and 49 CFR 537.6-537.7.  EPA would continue to issue certificates upon approval based on information submitted through the VERIFY database (see 40 CFR 1037.255).  End of year reports would continue to include the GEM results for all of the configurations built, along with credit/deficit balances, if applicable (see 40 CFR 1037.250 and 1037.730).
    GEM Inputs
In Phase 1, there were two inputs to GEM for vocational vehicles.
         * Steer tire coefficient of rolling resistance, and
         * Drive tire coefficient of rolling resistance
As discussed above in Section II and III.D, there are several additional inputs that are proposed for Phase 2.  In addition to the steer and drive tire CRR, the proposed inputs include the following:
         * Engine fuel map,
         * Engine full-load torque curve,
         * Engine motoring curve,
         * Transmission type,
         * Transmission gear ratios,
         * Drive axle ratio,
         * Loaded tire radius for drive and steer tires,
         * Idle Reduction,
         * Weight Reduction, and
         * Other pre-defined off-cycle technologies.
Driveline Inputs
As with tractors, for each engine family, an engine fuel map, full load torque curve, and motoring curve would be generated by engine manufacturers as inputs to GEM.  The test procedures for the torque and motoring curves are found in proposed 40 CFR part 1065. Section II.D.1.b describes these proposed procedures as well as the proposed new procedure for generating the engine fuel map.  Also similar to tractors, transmission specifications would be input to GEM. Any number of gears could be entered with a numerical ratio for each, and transmission type would be selectable as either a Manual, Automated Manual, Automatic, or Dual Clutch transmission.
As part of the driveline information needed to run GEM, drive axle ratio would be a user input.  If a configuration has a two-speed axle, the agencies propose that a manufacturer may enter the ratio that is expected to be engaged most often. We request comment on whether the agencies should allow this choice.  Two-speed axles are typically specified for heavy-haul vocational vehicles, where the higher numerical ratio axle would be engaged during transient driving conditions and to deliver performance needed on work sites, while the lower numerical ratio axle would be engaged during highway driving.  The agencies request comment on whether we should require GEM to be run twice, once with each axle ratio, where the output over the highway cycles would be used from the run with the lower axle ratio, and the output over the transient cycle would be used from the run with the higher axle ratio.
Tire size would be a new input to GEM that is necessary for the model to simulate the performance of the vehicle. The draft RIA Chapter 3 includes a description of how to measure tire size. For each model and nominal size of a tire, there are numerous possible sizes that could be measured, depending on whether the tire is new or "grown," meaning whether it has been broken in for at least 200 miles. Size could also vary based on load and inflation levels, air temperature, and tread depth.  The agencies request comment on aspects of measuring and reporting tire size that could be specified by rule, to avoid any unnecessary compliance burden of the Phase 2 program.
 Idle Reduction Inputs
Based on user inputs derived from engine testing described in Section II and draft RIA Chapter 3, GEM would calculate CO2 emissions and fuel consumption at both zero torque (neutral idle) and with torque set to Curb-Idle Transmission Torque for automatic transmissions in "drive" (as defined in 40 CFR 1065.510(f)(4) for variable speed engines) for use in the CO2 emission calculation in 40 CFR 1037.510(b).  The proposed regulations at 40 CFR part 1065 specify that that there must be two consecutive reference zero load idle points to establish  periods of zero load idle for purposes of calculating total work over an engine test cycle. These two idle points from the engine test would be used in GEM for purposes of calculating emissions during vehicle idling over the vocational vehicle test cycles.
The agencies welcome comments on the inclusion of these technologies into GEM in Phase 2.
Weight Reduction Inputs
In Phase 1, the agencies adopted tractor regulations that provided manufacturers with the ability to utilize high strength steel and aluminum components for weight reduction without the burden of entering the curb weight of every tractor produced.  In Phase 2, the agencies propose to apply relevant weights from the tractor lookup table to vocational vehicles.  As noted above, the agencies are proposing to recognize weight reduction by allocating one half of the weight reduction to payload in the denominator, while one half of the weight reduction would be subtracted from the overall weight of the vehicle in GEM.
To adapt the tractor table for vocational vehicles, the agencies propose to add lookup values for vehicles in lower weight classes.  We believe it is appropriate to also recognize the weight reduction associated with 6x2 axles.  We welcome comments on all aspects of weight reduction.  Components available for vocational vehicle manufacturers to select for weight reduction are shown below in Table V-29, below.
Table V-29 Proposed Phase 2 Weight Reduction Technologies for Vocational Vehicles
Component
Material
Unit Weight Reduced (lb) HHD Class 8
Unit Weight Reduced (lb) LHD or MHD Class 2b-7
Number per HHD Chassis
Number per LHD/MHD Chassis
Axle Hubs - Drive
Aluminum
                                                                             20
                                                                             20
                                                                              4
                                                                              2
Axle Hubs - Drive
High Strength Steel
                                                                              5
                                                                              5
                                                                              4
                                                                              2
Axle Hubs - Non-Drive
Aluminum
                                                                             20
                                                                             20
                                                                              2
                                                                              2
Axle Hubs - Non-Drive
High Strength Steel
                                                                            2.5
                                                                            2.5
                                                                              2
                                                                              2
Axle - Non-Drive
Aluminum
                                                                             60
                                                                             60
                                                                              1
                                                                              1
Axle - Non-Drive
High Strength Steel
                                                                             15
                                                                             15
                                                                              1
                                                                              1
Axle - 6x2 Configuration
Multi
                                                                            300
                                                                            N/A
                                                                              1
                                                                            N/A
Brake Drums - Drive
Aluminum
                                                                             35
                                                                             35
                                                                              4
                                                                              2
Brake Drums - Drive
High Strength Steel
                                                                            2.8
                                                                            2.8
                                                                              4
                                                                              2
Brake Drums - Non-Drive
Aluminum
                                                                             30
                                                                             30
                                                                              2
                                                                              2
Brake Drums - Non-Drive
High Strength Steel
                                                                              4
                                                                              4
                                                                              2
                                                                              2
Crossmember - Cab
Aluminum
                                                                             15
                                                                             15
                                                                              1
                                                                              1
Crossmember - Cab
High Strength Steel
                                                                              5
                                                                              5
                                                                              1
                                                                              1
Crossmember - Non-Suspension
Aluminum
                                                                              5
                                                                              5
                                                                              3
                                                                              3
Crossmember - Non-Suspension
High Strength Steel
                                                                            1.7
                                                                            1.7
                                                                              3
                                                                              3
Crossmember - Suspension
Aluminum
                                                                             25
                                                                             25
                                                                              1
                                                                              1
Crossmember - Suspension
High Strength Steel
                                                                              6
                                                                              6
                                                                              1
                                                                              1
Driveshaft
Aluminum
                                                                             20
                                                                             20
                                                                              1
                                                                              1
Driveshaft
High Strength Steel
                                                                              5
                                                                              5
                                                                              1
                                                                              1
Frame Rails
Aluminum
                                                                            220
                                                                            220
                                                                              2
                                                                              2
Frame Rails
High Strength Steel
                                                                             43
                                                                             43
                                                                              2
                                                                              2
Shackles
Aluminum
                                                                            1.7
                                                                            1.7
                                                                              6
                                                                              4
Shackles
High Strength Steel
                                                                            0.5
                                                                            0.5
                                                                              6
                                                                              4
Suspension Brackets, Hangers
Aluminum
                                                                           16.7
                                                                           16.7
                                                                              6
                                                                              4
Suspension Brackets, Hangers
High Strength Steel
                                                                              5
                                                                              5
                                                                              6
                                                                              4
Transmission Case
Aluminum
                                                                             50
                                                                             45
                                                                              1
                                                                              1
Transmission Case
High Strength Steel
                                                                             12
                                                                             12
                                                                              1
                                                                              1
Transmission Clutch Housing
Aluminum
                                                                             47
                                                                             34
                                                                              1
                                                                              1
Transmission Clutch Housing
High Strength Steel
                                                                             10
                                                                             10
                                                                              1
                                                                              1
Transmission Clutch Levers
Aluminum
                                                                             20
                                                                             20
                                                                              1
                                                                              1
Transmission Clutch Levers
High Strength Steel
                                                                              4
                                                                              4
                                                                              1
                                                                              1
Wheels - Dual
Aluminum
                                                                             21
                                                                             21
                                                                             10
                                                                              6
Wheels - Dual
High Strength Steel
                                                                              8
                                                                              8
                                                                             10
                                                                              6
Wheels - Dual
Lightweight Aluminum
                                                                             30
                                                                             30
                                                                             10
                                                                              6
Wheels - Wide Base Single
Aluminum
                                                                            139
                                                                            139
                                                                             10
                                                                              6
Wheels - Wide Base Single
High Strength Steel
                                                                             84
                                                                             84
                                                                             10
                                                                              6
Wheels - Wide Base Single
Lightweight Aluminum
                                                                            147
                                                                            147
                                                                             10
                                                                              6
    Test Procedures
Powertrain families are defined in Section II.C.3.b, and powertrain test procedures are discussed in the draft RIA Chapter 3. The agencies propose that the results from testing a powertrain configuration using the matrix of tests described in draft RIA Chapter 3.6 could be applied broadly across all vocational vehicles in which that powertrain would be installed.
As in Phase 1, the rolling resistance of each tire would be measured using the ISO 28850 test method for drive tires and steer tires planned for fitment to the vehicle being certified. Once the test CRR values are obtained, a manufacturer would input the CRR values for the drive and steer tires separately into the GEM.  For vocational vehicles in Phase 2, the agencies propose that the vehicle load would be distributed with 30 percent of the load over the steer tires and 70 percent of the load over the drive tires. With these data entered, the amount of GHG reduction attributed to tire rolling resistance would be incorporated into the overall vehicle compliance value.
    Useful Life and In-Use Standards
Section 202(a)(1) of the CAA specifies that emissions standards are to be applicable for the useful life of the vehicle.  The standards that EPA is proposing would apply to individual vehicles and engines at production and in use.  NHTSA is not proposing in-use standards for vehicles and engines.
Manufacturers may be required to submit, as part of the application for certification, an engineering analysis showing that emission control performance will not deteriorate during the useful life, with proper maintenance.  If maintenance will be required to prevent or minimize deterioration, a demonstration may be required that this maintenance will be performed in use. (See 40 CFR 1037.241).
EPA is proposing to continue the Phase 1 approach to adjustment factors and deterioration factors.  The technologies on which the Phase 1 vocational vehicle standards were predicated were not expected to have any deterioration of GHG effectiveness in use.  However, the regulations provided a process for manufacturers to develop deterioration factors (DF) if they needed. We anticipate that some hybrid powertrain systems may experience some deterioration of effectiveness with age of the energy storage device.  We believe the regulations in place currently provide adequate instructions to manufacturers for developing DF where needed. We request comment on whether any changes to the DF process are needed.
As with engine certification, a manufacturer must provide evidence of compliance through the regulatory useful life of the vehicle. Factors influencing vehicle-level GHG performance over the life of the vehicle fall into two basic categories: vehicle attributes and maintenance items.  Each category merits different treatment from the perspective of assessing useful life compliance, as each has varying degrees of manufacturer versus owner/operator responsibility.
For vocational vehicles, attributes generally refers to components that are installed by the manufacturer to meet the standard, whose reduction properties are assessed at the time of certification, and which are expected to last the full life of the vehicle with effectiveness maintained as new for the life of the vehicle with no special maintenance requirements.  To assess useful life compliance, we are proposing to follow a design-based approach that would ensure that the manufacturer has robustly designed these features so they can reasonably be expected to last the useful life of the vehicle.
For vocational vehicles, maintenance items generally refers to items that are replaced, renewed, cleaned, inspected, or otherwise addressed in the preventative maintenance schedule specified by the vehicle manufacturer. Replacement items that have a direct influence on GHG emissions are primarily tires and lubricants, but may also include hybrid system batteries. Synthetic engine oil may be used by vehicle manufacturers to reduce the GHG emissions of their vehicles. Manufacturers may specify that these fluids be changed throughout the useful life of the vehicle. If this is the case, the manufacturer should have a reasonable basis that the owner/operator will use fluids having the same properties. This may be accomplished by requiring (in service documentation, labeling, etc.) that only these fluids can be used as replacements.  In this proposal, the only maintenance costs we have quantified are those for tire replacement, as described in Section IX.C.3 and the draft RIA Chapter 7.1.  The agencies invite comments with information related to maintenance costs that the agencies should quantify for the final rules.
For current non-hybrid technologies, if the vehicle remains in its original certified condition throughout its useful life, it is not believed that GHG emissions would increase as a result of service accumulation. As in Phase 1, the agencies propose allowing the use of an assigned deterioration factor of zero where appropriate in Phase 2; however this does not negate the responsibility of the manufacturer to ensure compliance with the emissions standards throughout the useful life.  The vehicle manufacturer would be primarily responsible for providing engineering analysis demonstrating that vehicle attributes will last for the full useful life of the vehicle. We anticipate this demonstration would show that components are constructed of sufficiently robust materials and design practices so as not to become dysfunctional under normal operating conditions.