network is in place to correct any such conditions. The vehicle
manufacturer also bears responsibility in the event that an emission-
related recall is necessary.
(a) Certification Process
    In order to obtain a certificate of conformity for the tractor, the
tractor manufacturer will complete a compliance demonstration, showing
that their product meets emission standards as well as other regulatory
requirements. For purposes of this demonstration, vehicles with similar
emission characteristics throughout their useful life are grouped
together in vehicle families, which are defined primarily by the
regulatory subclass of the vehicle. Manufacturers may further classify
vehicles together into sub-families within a given vehicle family for a
given regulatory subcategory. Examples of characteristics that would
define a vehicle sub-family for heavy-duty vehicles are wheel and tire
package, aerodynamic profile, tire rolling resistance, and vehicle
speed limiting system. Compliance with the emission standards (or FEL)
will be determined at the sub-family level.
    Under this system, the worst-case vehicle configuration would be
selected based on having the highest fuel consumption, and all other
configurations within the family or sub-family are assumed to have
emissions and fuel consumption at or below the parent model and
therefore in compliance with CO2 emission and fuel
consumption standards. Any vehicle within the family can be subject to
selective enforcement auditing in addition to confirmatory or other
administrator testing.
    Vehicle families for Class 7 and 8 combination tractors will
utilize the standardized 12-digit naming convention, as described along
with the engine certification process in Section V.C.1.a, above. As
with engines, each certifying vehicle manufacturer will have a unique
three digit code assigned to them. Currently, there is no 5th digit
(industry sector) code for this class of vehicles, for which we
proposed to use the next available character, ``2.'' The agencies
originally proposed that engine displacement be included in the vehicle

family name, however the wide range of engines available across most
regulatory subcategories makes this requirement irrelevant and
unnecessary at the time of this rulemaking. Therefore, we are reserving
the remaining characters for California ARB and/or manufacturer use,
such that the result is a unique vehicle family name.
    Class 7 and 8 tractors share several common traits, such as the
trailer attachment provisions, number of wheels, and general
construction. However, further inspection reveals key differences
related to GHG emissions. Payloads hauled by Class 7 tractors are
significantly less than Class 8 tractors. In addition, Class 8 vehicles
may have provisions for hoteling (``sleeper cabs''), which results in
an increase in size as well as the addition of comfort features like
power and climate control for use while the truck is parked. Both
segments may have various degrees of roof fairing to provide better
aerodynamic matching to the trailer being pulled. This is a feature
which can help reduce CO2 emissions significantly when
properly matched to the trailer, but can also increase CO2
emissions if improperly matched. Based on these differences, it is
reasonable to expect differences in CO2 emissions, and
therefore these properties form the basis for the final combination
tractor regulatory subcategories.
    The various combinations of payload, cab size, and roof profile
result in nine final regulatory subcategories for Class 7 and 8
tractors. Class 7 tractors are divided into three regulatory
subcategories: one for low, one for mid roof height profiles, and one
for high roof profiles. The Class 7 tractors are subject to a 10 year,
185,000 regulatory useful life. Class 8 tractors are split into six
regulatory subcategories reflecting two cab sizes (day and sleeper) and
three roof height profiles (low, mid, and high). All Class 8 tractors
are subject to a 10 year, 435,000 mile regulatory useful life.
(b) Demonstrating Compliance With the Final Standards
(i) CO2 and Fuel Consumption Standards
    As discussed at proposal, although whole-vehicle certification may
be ultimately desirable for these vehicles, it is essentially
infeasible to require it now. See 75 FR at 74270-71. Most commenters
agreed, as did the NAS Report. Accordingly, again consistent with the
NAS Report, the agencies have developed a predictive model for
demonstrating compliance with these initial standards for combination
tractors. The agencies will continue to work toward improved methods
for whole vehicle performance characterization, as suggested by some
commenters.
Model
    Vehicle modeling will be conducted using the agencies' simulation
model, the GEM, which is described in detail in Chapter 4 of the RIA
with responses to comments in the Summary and Analysis of Comments
Document Section 7. Basically, this model functions by defining a
vehicle configuration and then exercises the model over various drive
cycles. Several initialization files are needed to define a vehicle,
which include mechanical attributes, control algorithms, and driver
inputs. The majority of these inputs will be predetermined by EPA and
NHTSA for the purposes of vehicle certification. The net results from
the GEM are weighted CO2 emissions and fuel consumption
values over the drive cycles. The CO2 emission result will
be used for demonstrating compliance with vehicle CO2
standards while the fuel consumption result will be used for
demonstrating compliance with the fuel consumption standards.
    The vehicle manufacturer will be responsible for entering up to
seven inputs relating to the GHG performance of a vehicle configuration
although, depending on the regulatory category, fewer inputs may be
required. These inputs include the regulatory category, coefficient of
drag, steer tire rolling resistance, drive tire rolling resistance,
vehicle speed limit, vehicle weight reduction, and idle reduction
credit. For the GEM inputs relating to aerodynamics, the agencies have
finalized lookup tables for frontal area and coefficient of drag based
on typical performance levels across the industry. Manufacturers are
responsible for assessing the aerodynamic performance of their vehicles
through testing or a combination of testing and modeling. This test
data is then used to select the most appropriate agency-defined bin for
entry into the GEM.
    Tire rolling resistance is simply the measured rolling resistance
of the tire in kg per metric ton as described in ISO 28580:2009. This
measured value is expected to be the result of three repeat
measurements of three different tires of a given design, giving a total
of nine data points. It is the average of these nine results that will
be entered into the GEM. Tire rolling resistance may be determined by
either the vehicle or tire manufacturer. In the latter case, a signed
statement from the tire manufacturer confirming testing was conducted
in accordance with this part is required.
    As previously described, limiting vehicle speed can have a
significant effect on fuel consumption and we believe that
manufacturers should be recognized for including technology that
facilitates these limits. Also as described, these vehicle speed
limiters are not likely to be a simple device with a fixed top speed.
``Soft top'' limits based on driver behavior and limit expiration dates
(or mileage) are two of the most common scenarios. To properly assess
the GHG and fuel consumption benefits in light of these features, we
are defining the proper methodology for entering the vehicle speed
limit into the GEM. This is based on an equation including terms for
VSL expiration (expiration factor) and VSL soft-top (soft-top factor
and soft-top VSL). The result will be an effective vehicle speed limit
reflecting the expected mileage and time that the limit will be used
for. Additional details regarding this equation and its derivation can
be found in RIA Chapter 2.
    For vehicle weight reduction, the agencies are primarily addressing
the reduction of weight and perhaps number of wheels. This reduction is
assessed relative to a standard combination tractor configuration with
dual-wide rear tires with conventional steel wheels. Manufacturers may
elect to use single-wide tires/wheels and/or aluminum (or light-weight
aluminum) wheels or other components to reduce the weight of their
vehicles. The agencies have defined standard weight reduction levels
associated with each weight reduction technology for entry into the
GEM. These reductions are listed in pounds per component, so
manufacturers will need to multiply this reduction by the number of
affected components for their total weight reduction entry into the
GEM.
    Manufacturers of sleeper cabs electing to limit idle time to 300
seconds or less can claim a GHG benefit of 5 g/ton-mile and should be
entered into the GEM as such. This benefit cannot be scaled to reflect
shorter or longer allowed idle times, but can be scaled based upon
expiration date.
    The agencies will utilize the appropriate engine map reflecting use
of a certified engine in the truck (and will enter the same value even
if an engine family is certified to the temporary percent reduction
alternative standard, in order to evaluate vehicle performance
independently of engine performance.) We believe this approach reduces
the testing burden placed upon manufacturers, yet adequately assesses

improvements associated with select technologies. The model will be
publicly available and will be found on EPA's Web site.
    The agencies reserve the right to independently evaluate the inputs
to the model by way of Administrator testing to validate those model
inputs. The agencies also reserve the right to evaluate vehicle
performance using the inputs to the model provided by the manufacturer
to confirm the performance of the system using GEM. This could include
generating emissions results using the GEM and the inputs as provided
by the manufacturer based on the agency's own runs. This could also
include conducting comparable testing to verify the inputs provided by
the manufacturer. In the event of such testing or evaluation, the
Administrator's results become the official certification results, the
exception being that the manufacturer may continue to use their data as
initially submitted, provided it represents a worst-case condition over
the Administrator's results.
    To better facilitate the entry of only the appropriate parameters,
the agencies will provide a graphical user interface in the model for
entering data specific to each vehicle. In addition, EPA will provide a
template that facilitates batch processing of multiple vehicle
configurations within a given family. It is expected that this template
will be submitted to EPA as part of the certification process for each
certified vehicle family or subfamily.
    For certification, the model will exercise the vehicle over three
test cycles; one transient and two steady-state. For the transient
test, we are using the heavy heavy-duty diesel truck (HHDDT) transient
test cycle, which was developed by the California Air Resources Board
and West Virginia University to evaluate heavy-duty vehicles. The
transient mode simulates urban, start-stop driving, featuring 1.8 stops
per mile over the 2.9 mile duration. The two steady state test points
are reflective of the tendency for some of these vehicles to operate
for extended periods at highway speeds. Based on data from the EPA's
MOVES database, and common highway speed limits, we are finalizing
these two points to be 55 and 65 mph.
    The model will predict the total emissions results from each
configuration using the unique properties entered for each vehicle.
These results are then normalized to the payload and distance covered,
so as to yield a gram/ton-mile result, as well as a fuel consumption
(gal/1,000 ton-mile) result for each test cycle. As with engine and
vehicle testing, certification will be based on the worst-case
configuration within a vehicle family.
    The results from all three tests are then combined using weighting
factors, which reflect typical usage patterns. The typical usage
characteristics of Class 7 and 8 tractors with day cabs differ
significantly from Class 8 tractors with sleeper cabs. The trucks with
day cabs tend to operate in more urban areas, have a limited travel
range, and tend to return to a common depot at the end of each shift.
Class 8 sleeper cabs, however, are typically used for long distance
trips which consist of mostly highway driving in an effort to cover the
highest mileage in the shortest time. For these reasons, we proposed
that the cycles are weighted differently for these two groups of
vehicles. For Class 7 and 8 trucks with day cabs, we propose weights of
64%, 17%, and 19% (65 mph, 55 mph, and transient, resp.). For Class 8
with sleeper cabs, the high speed cruise tendency results in final
weights of 86%, 9%, and 5% (65 mph, 55 mph, and transient,
respectively). These final, weighted emission results are compared to
the emission standard to assess compliance. The agencies received
comments regarding the duty cycles and the weighting factors used for
assessing emissions compliance. In making final determination for the
cycle weighting factors, the agencies considered those comments, as
well as the agencies' own data in determining the final weighting
factors and duty cycles to be used for determining emissions
compliance. Demonstration of compliance is also available through the
use of credits generated as part of the Averaging, Banking, and Trading
Program (ABT) as described earlier in this Preamble. Additionally,
compliance may be demonstrated through the use of a Vehicle Speed
Limiter (VSL) and the application of the VSL is accounted for as
another input to the GEM for assessing GHG and fuel consumption
emissions performance.
Durability Testing
    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.
    The category of vehicle attributes generally refers to aerodynamic
features, such as fairings, side-skirts, air dams, air foils, etc.,
which are installed by the manufacturer to reduce aerodynamic drag on
the vehicle. These features have a significant impact on GHG emissions
and their emission reduction properties are assessed early in the
useful life (at the time of certification). These features are expected
to last the full life of the vehicle without becoming detached,
cracked/broken, misaligned, or otherwise not in a state which provides
the original GHG emissions reduction. In the absence of the
aforementioned failure modes, the performance of these features is not
expected to degrade over time and the benefit to reducing GHG emissions
is expected to last for the life of the vehicle with no special
maintenance requirements. To assess useful life compliance, we are
following a design-based approach which will ensure that the
manufacturer has robustly designed these features so they can
reasonably be expected to last the useful life of the vehicle.
    The category of maintenance items 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. 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.
    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. This is based on the
assumption that as components such as tires wear, the rolling
resistance due to friction is likely to stay the same or decrease. With
all other components remaining equal (tires, aerodynamics, etc), the
overall drag force would stay the same or decrease, thus not
significantly changing GHG emissions at the end of useful life. It is
important to remember however, that this vehicle assessment does not
take into account any engine-related wear affects, which may in fact
increase GHG emissions over time. The agencies received comments from
engine and tractor manufacturers requesting an assigned deterioration
factor of zero for GHG

emissions. As discussed previously, the agencies will allow the use of
an assigned deterioration factor of zero where appropriate in Phase 1,
however this does not negate the responsibility of the manufacturer to
ensure compliance with the emissions standards throughout the useful
life.
    For the reasons explained above, we believe that for the first
phase of this program, it is most important to ensure that the vehicle
remain in its certified configuration throughout the useful life. This
can most effectively be accomplished through engineering analysis and
specific maintenance instructions provided by the vehicle manufacturer.
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 will show that components are constructed of sufficiently
robust materials and design practices so as not to become dysfunctional
under normal operating conditions. For instance, we expect aerodynamic
fairings to be constructed of materials similar to that of the main
body of the vehicle (fiberglass, steel, aluminum, etc) and have
sufficient support and attachment mechanisms so as not to become
detached or broken under normal, on-highway driving.
(ii) EPA's Air Conditioning Leakage Standards
    Heavy-duty vehicle air conditioning systems contribute to GHG
emissions in two ways. First, operation of the air conditioning unit
places an accessory load on the engine, which increases fuel
consumption. Second, most modern refrigerants are HFC-based, which have
significant global warming potential (GWP=1430). For heavy-duty
vehicles, the load added by the air conditioning system is
comparatively small compared to other power requirements of the
vehicle. Therefore, we are not targeting any GHG reduction due to
decreased air conditioning usage or higher efficiency A/C units for
this final action. However, refrigerant leakage, even in very small
quantities, can have significant adverse effects on GHG emissions.
    Refrigerant leakage is a concern for heavy-duty vehicles, similar
to light-duty vehicles. To address this, EPA is finalizing a design-
based standard for reducing refrigerant leakage from heavy-duty pickups
and vans and combination tractors. This standard is based off using the
best practices for material selection and interface sealing, as
outlined in SAE publication J2727. Based on design criteria in this
publication, a leakage ``score'' can be assessed and an estimated
annual leak rate can be made for the A/C system based on the
refrigerant capacity. (There is no requirement for vocational vehicle
AC leakage for reasons explained at 75 FR 74211.)
    At the time of certification, manufacturers will be required to
outline the design of their system, including the specification of
materials and construction methods. They will also need to supply the
leakage score developed using SAE J2727 and the refrigerant volume of
their system to determine the leakage rate per year. If the certifying
manufacturer does not complete installation of the air conditioning
unit, detailed instructions must be provided to the final installer who
ensures that the A/C system is assembled to meet the low-leakage
standards. These instructions will also need to be provided at the time
of certification, and manufacturers must retain all records relating to
auditing of the final assembler.
(c) In-Use Standards
    As previously addressed, the drive-cycle dependence of
CO2 emissions makes NTE-based in-use testing impractical. In
addition, we believe the reporting of CO2 data from the
criteria pollutant in-use testing program will be helpful in future
rulemaking efforts. For these reasons, we are not finalizing an NTE-
based in-use testing program for Class 7 and 8 combination tractors for
this program.
    In the absence of NTE-based in-use testing, provisions are
necessary for verifying that production vehicles are in the certified
configuration, and remain so throughout the useful life. Perhaps the
easiest method for doing this is to verify the presence of installed
emission-related components. This would basically consist of a vehicle
audit against what is claimed in the certification application. This
includes verifying the presence of aerodynamic components, such as
fairings, side-skirts, and gap-reducers. In addition, the presence of
idle-reduction and speed limiting devices would be verified. The
presence of LRR tires could be verified at the point of initial sale;
however verification at other points throughout the useful life would
be non-enforceable for the reasons mentioned previously.
    The category of wear items primarily relates to tires. It is
expected that vehicle manufacturers will equip their trucks with LRR
tires, as they may provide a reduction in GHG emissions. The tire
replacement intervals for this class of vehicle is normally in the
range of 50,000 to 100,000 miles, which means the owner/operator will
be replacing the tires at several points within the useful life of the
vehicle. We believe that as LRR tires become more common on new
equipment, the aftermarket prices of these tires will also decrease.
The primary barrier to the introduction of more fuel efficient tire
designs into the truck market is the upfront costs of tire development
and upfront capital costs for new production machinery (e.g., new tire
molds). Once manufacturers have sunk these costs into new tire designs
and production facilities in order to meet our vehicle standards, there
is little barrier for bringing these better products into the
replacement tire market as well. Our regulations will effectively force
OEMs to make these investments in tire designs and, having done so,
should lead to better tires not only for new vehicles but in the
replacement tire market as well. Along with decreasing tire prices, the
fuel savings realized through use of LRR tires will ideally provide
enough incentive for owner/operators to continue purchasing these
tires. Thus, the inventory modeling in this final action reflects the
continued use of LRR tires through the life of the vehicle.
(2) Enforcement Provisions
    As identified above, a significant amount of vehicle-level GHG
reduction is anticipated to come from the use of components
specifically designed to reduce GHG emissions. Examples of such
components include LRR tires, aerodynamic fairings, idle reduction
systems, and vehicle speed limiters. At the time of certification,
vehicle manufacturers will specify which components will be on their
vehicle when introduced into commerce. Based on this list of installed
components, GHG emissions performance of the vehicle will be assessed
using the GEM, and compliance with the family (or subfamily) emissions
limit will need to be shown. Given the ability of manufacturers to
demonstrate compliance through the use of flexibility provisions, as
previously described, that will be taken into account when assessing
the performance for purposes of enforcement. Additionally, should
enforcement action be necessary against systems certified using the
flexibility provisions, credit balances generated through the use of
the provisions may be reduced as a consequence of enforcement activity.
As described in the in-use testing section, it is important to have the
ability to determine if the vehicle is in the certified configuration
at the time of sale.

    Perhaps the most practical and basic method of verifying that a
vehicle is in its certified configuration is through a vehicle
emissions control information label, similar to that used for engines
and light-duty vehicles. We proposed that this label list identifying
features of the vehicle, including model year, vehicle model, certified
engine family, vehicle manufacturer, test group, and GHG emissions
category. In addition, this label would list emission-related
components that an inspector could reference in the event of a field
inspection. Possible examples may include LRR (for LRR tires), ARF
(aerodynamic roof fairing), and ARM (aerodynamic rearview mirrors).
With this information, inspectors could verify the presence and
condition of attributes listed as part of the certified configuration.
    Several comments were received voicing concern that the large
number of vehicle permutations within a given vehicle family (and
perhaps vehicle subfamily) would lead to a large number of unique
labels, at significant cost and labor burden to the manufacturer. In
addition, including generic emission control system (EC) identifiers
for vehicles would add a significant burden while providing little
usable information for inspectors. A common example given in the
comments was that simply identifying ``ARF'' for a roof fairing would
not be sufficiently detailed for an inspector to know whether the
correct roof fairing is present. As a result of these concerns,
commenters suggested that vehicle labels only include a minimal amount
of information such as a compliance statement, vehicle family name, and
date of manufacture.
    The agencies generally agree with the concerns raised by the
commenters and do not wish to add burdensome and arbitrary labeling
requirements. Concurrently, we also remain committed to giving agency
inspectors adequate tools to ensure a vehicle is in its certification
at least at the time of sale. Therefore, we are finalizing a vehicle
label requirement that includes:

--Compliance statement.
--Vehicle manufacturer.
--Vehicle family (and subfamily).
--Date of manufacture.
--Regulatory subcategory.
--Emission control system identifiers.

    To address the concerns from vehicle manufacturers identified
above, particularly related to emission control (EC) identifiers, we
believe a combination of selectable information on the label as well as
a set of EPA-defined EC identifiers will provide a useful, but not
overly burdensome labeling scheme. Since the intent of these
identifiers is to provide inspectors with a means for simply verifying
the presence of a component, we do not believe overly detailed
identifiers are necessary, particularly for tires and aerodynamic
components. For instance, current engine regulations require that
three-way catalysts be identified on engine labels as ``TWC.'' However,
unique details such as catalyst size, loading, location, and even the
number of catalysts are not on the label. In similar fashion, we
believe that identifying tires and aerodynamic components in a general
sense will prove similarly effective in determining if a vehicle has
been built as intended or if it has been modified prior to being
offered for sale.
    EPA is requiring that components for which vehicle certification is
dependent upon be identified on the label. This includes limited
aerodynamic components (roof fairings, side skirts, & gap reducers),
vehicle speed limiters, LRR tires, and idle reduction components. If
vehicle certification also depends on the use of innovative or advanced
technologies, this too must be included on the label. The following
identifiers must be used for the emission control label:
Vehicle Speed Limiters
--VSL--Vehicle speed limiter.
--VSLS--``Soft-top'' vehicle speed limiter.
--VSLE--Expiring vehicle speed limiter.
--VSLD--Vehicle speed limiter with both ``soft-top'' and expiration.
Idle Reduction Technology
--IRT5--Engine shutoff after 5 minutes or less of idling.
--IRTE--Expiring engine shutoff.
Tires
--LRRD--Low rolling resistance tires--Drive (CRR of 8.2 kg/metric ton
or less).
--LRRS--Low rolling resistance tires--Steer (CRR of 7.8 kg/metric ton
or less).
--LRRA--Low rolling resistance tires--All (meeting appropriate criteria
for steer & drive).
Aerodynamic Components
--ATS--Aerodynamic side skirt and/or fuel tank fairing.
--ARF--Aerodynamic roof fairing.
--ARFR--Adjustable height aerodynamic roof fairing.
--TGR--Gap reducing fairing (tractor to trailer gap).
Other Components
--ADV--Vehicle includes advanced technology components.
--ADVH--Vehicle includes hybrid powertrain.
--INV--Vehicle includes innovative technology components.

    On the vehicle label, several (if not all), available EC
identifiers available in a given subfamily can be listed and the
appropriate selections can be made at the time of assembly based on
each unique vehicle configuration. This practice is common on engine
ECI labels (normally for month/year of manufacture) and selections are
made using a punch, stamp, check mark or other permanent method. This
provides inspectors with the information they need while still
affording flexibility to manufacturers with several unique vehicle
configurations.
    At the time of certification, manufacturers will be required to
submit an example of their vehicle emission control label such that EPA
can verify that all critical elements mentioned above are present. In
addition to the label, manufacturers will also need to describe where
the unique vehicle identification number and date of production can be
found on the vehicle (if the date is not present on the label).
    The agencies received several comments requesting the inclusion of
consumer-focused labels for heavy-duty vehicles. These requests mainly
involved labels similar to those found on passenger vehicles, allowing
consumers to easily determine and compare fuel efficiency between
vehicles. While we agree that such labels proven to be valuable to
consumers in the light-duty market when shopping and comparing
vehicles, the vast array of in-use drive cycles for heavy-duty vehicles
and significant impact on GHG emissions reduce the intrinsic value of
such fuel efficiency data to consumers. Additionally, many heavy-duty
vehicles are unique and purpose-built which prevents direct comparison
to other vehicles. The agencies may revisit this topic for future
rulemaking activities, however there is no consumer label requirement
in this final action.
(3) Other Certification Provisions
(a) Warranty
    Section 207 of the CAA requires manufacturers to warrant their
products to be free from defects that would otherwise cause non-
compliance with emission standards. For purposes of this regulation,
vehicle manufacturers must warrant all components which form the

basis of the certification to the GHG emission standards. The emission-
related warranty covers vehicle speed limiters, idle shutdown systems,
fairings, hybrid system components, and other components to the extent
such components are included in the certified emission controls. The
emission-related warranty also covers tires and all components whose
failure would increase a vehicle's evaporative emissions (for vehicles
subject to evaporative emission standards, which could include
components which received innovative or advanced technology credits).
In addition, the manufacturer must ensure these components and systems
remain functional for the warranty period defined in 40 CFR part 86 for
the engine used in the vehicle, generally defined as half of the
regulatory useful life. As with heavy-duty engines, manufacturers may
offer a more generous warranty, however the emissions related warranty
may not be shorter than any other warranty offered without charge for
the vehicle. If aftermarket components are installed (unrelated to
emissions performance) which offer a longer warranty, this will not
impact emission related warranty obligations of the vehicle
manufacturer. NHTSA, for this phase of the program, is not finalizing
any warranty requirements relating to its fuel consumption rule.
    Several comments were received from vehicle manufacturers voicing
concern that tire warranties should be the responsibility of the tire
manufacturer, not the vehicle manufacturer. It has been, and remains,
EPA policy to hold the certifying entities responsible for warranty
obligations. In this case, tire manufacturers are not certificate
holders and therefore we do not believe it is appropriate for them to
independently warrant their products. The agencies see this as no
different than requiring turbocharger or fuel injector manufacturers to
provide warranties related to heavy-duty engines. However, we do
believe that vehicle manufacturers can and should hold tire
manufacturers responsible for warranty of their products as part of
their sourcing and purchasing agreements. As proposed, tires are only
required to be warranted for the first life of the tires (vehicle
manufacturers are not expected to cover replacement tires). For heavy-
duty pickups and vans and combination tractors, the vehicle
manufacturer is also required to warrant the A/C system against design
or manufacturing defects causing refrigerant leakage in excess of the
standard. The warranty period for the A/C system is identical to the
vehicle warranty period as described above.
    At the time of certification, manufacturers must supply a copy of
the warranty statement that will be supplied to the end customer. This
document should outline what is covered under the GHG emissions related
warranty as well as the length of coverage. Customers must also have
clear access to the terms of the warranty, the repair network, and the
process for obtaining warranty service.
(b) Maintenance
    Vehicle manufacturers are required to outline maintenance schedules
that ensure their product will remain in compliance with emission
standards throughout the useful life of the vehicle. For heavy-duty
vehicles, such maintenance may include fluid/lubricant service, fairing
adjustments, or service to the GHG emission control system. This
schedule is required to be submitted as part of the application for
certification. Maintenance that is deemed to be critical to ensuring
compliance with emission standards is classified as ``critical
emission-related maintenance.'' Generally, manufacturers are
discouraged from specifying that critical emission-related maintenance
is needed within the regulatory useful life of the engine. However, if
such maintenance is unavoidable, manufacturers must have a reasonable
basis for ensuring it is performed at the correct time. This may be
demonstrated through several methods including survey data indicating
that at least 80 percent of engines receive the required maintenance
in-use or manufacturers may provide the maintenance at no charge to the
user.
    Manufacturers will be required to submit the recommended emission-
related maintenance schedule (and other service related documentation)
at the time of certification. This documentation should provide
sufficient detail to allow the owner/operator of the vehicle to
maintain the emission control system in a way that will ensure
functionality as intended. This would include items such as periodic
inspection of aerodynamic components and maintenance unique to advanced
or innovative technologies. In addition, these instructions should
provide the owner/operator with adequate information to replace
consumable components (such as tires) with comparable replacements.
    Since low rolling resistance tires are key emission control
components under this program, and will likely require replacement at
multiple points within the life of a vehicle, it is logical to clarify
how this fits into the emission-related maintenance requirements. While
the agencies encourage the exclusive use of LRR tires throughout the
life of heavy-duty vehicles, we recognize that it is inappropriate at
this time to hold vehicle manufacturers responsible for ensuring that
this occurs. Additionally, we believe that owner/operators have a
legitimate financial motivation for ensuring their vehicles are as fuel
efficient as possible, which includes purchasing LRR replacement tires.
However owner/operators may not have a sound knowledge of which
replacement tires to purchase to retain the as-certified fuel
efficiency of their vehicle. To address this concern and in response to
comments from vehicle manufacturers, we are requiring that vehicle
manufacturers supply adequate information in the owner's manual to
allow the owner/operator of the vehicle to purchase tires meeting or
exceeding the rolling resistance performance of the original equipment
tires. We expect that these instructions will be submitted to EPA as
part of the application for certification.
(c) Certification Fees
    Similar to engine certification, the agency will assess
certification fees for heavy-duty vehicles. The proceeds from these
fees are used to fund the compliance and certification activities
related to GHG regulation for this regulatory category. In addition to
the certification process, other activities funded by certification
fees include EPA-administered in-use testing, selective enforcement
audits, and confirmatory testing. At this point, the exact costs
associated with the heavy-duty vehicle GHG compliance are not well
known. EPA will assess its compliance program cost associated with this
program and assess the appropriate level of fees. We anticipate that
fees will be applied based on vehicle families, following the light-
duty vehicle approach.
(d) Requirements for Conducting Aerodynamic Assessment Using the
Modified Coastdown Reference Method and Alternative Aerodynamic Methods
    The requirements for conducting aerodynamic assessment using the
modified coastdown reference method and alternative aerodynamic methods
includes two key components: adherence to a minimum set of standardized
criteria for each allowed method and submittal of aerodynamic values
and supporting information on an annual basis for the purposes of
certifying vehicles to a particular

aerodynamic bin as discussed in Section II.
    First, we are finalizing requirements for conducting the modified
coastdown reference method and each of the alternative aerodynamic
assessment methods. We will cite approved and published standards and
practices, where feasible, but will define criteria where none exists
or where more current research indicates otherwise. A description of
the requirements for each method is discussed later in this section.
The manufacturer will be required to provide performance data on its
vehicles and attest to the accuracy of the information provided.
    Second, to ensure continued compliance, manufacturers will be
required to provide a minimum set of information on an annual basis at
certification time 1) to support continued use of an aerodynamic
assessment method and 2) to assign an aerodynamic value based on the
applicable aerodynamic bins. The information supplied to the agencies
should be based on an approved aerodynamic assessment method and adhere
to the requirements for conducting aerodynamic assessment mentioned
above.
    The annual submission may be based on coastdown testing conducted
consistent with the modified protocol detailed in this rulemaking or
with an approved alternative method. The coastdown testing must be
conducted using the Modified Protocol which uses SAE J1263 as a basis
with some elements of SAE J2263 (e.g., post-processing and analysis
techniques), in addition to the modifications developed in response to
industry comments which raised concerns regarding test to test
variability.
    In addition to 8 valid coastdown runs in each direction,
manufacturers using in-house test methods should provide an adjustment
factor for relating their drag coefficient based on their in-house
method to the reference method, modified coastdown. The basis for the
adjustment factor is:

Adjustment Factor = Cd coastdown / Cd in-house

    For the test article used for certification that differs from the
test article used for reference method testing, determine Cd to use for
aerodynamics bin determination as described below.

Cd certification BIN = Adjustment Factor x
Cdin-house measured

    The specific requirements for the test article used in reference
method testing using the coastdown procedures should meet the
requirements listed in Table V-2 through Table V-5, below.

         Table V-2--Reference Method Test Vehicle Specifications
------------------------------------------------------------------------
                                             53' air ride dry vans
------------------------------------------------------------------------
Length...............................  53 feet (636 inches) +/- 1 inch.
Width................................  102 inches +/- 0.5 inches.
Height...............................  102 inches (162 inches or 13
                                        feet, 6 inches (+ 0.0 inch/ -1
                                        inch) from the ground).
Capacity.............................  3800 cubic feet.
Assumed trailer load/capacity........  45,000 lbs.
Suspension...........................  Any (see ``trailer ride height''
                                        below).
Corners..............................  Rounded with a radius of 5.5
                                        inches +/- 0.5 inches.
Bogie/Rear Axle Position.............  Tandem axle (std), 146 inches +/-
                                        3.0 inches from rear axle
                                        centerline to rear of trailer.
                                        Set to California position.
Skin.................................  Generally smooth with flush
                                        rivets.
Scuff band...........................  Generally smooth, flush with
                                        sides (protruding <= \1/8\
                                        inch).
Wheels...............................  22.5 inches. Duals. Std mudflaps.
Doors................................  Swing doors.
Undercarriage/Landing Gear...........  Std landing gear, no storage
                                        boxes, no tire storage, 105
                                        inches +/- 4.0 inches from
                                        centerline of king pin to
                                        centerline of landing gear.
Underride Guard......................  Equipped in accordance with 49
                                        CFR 393.86.
------------------------------------------------------------------------
Tires for the Standard Trailer and the Tractor:
    a. Size: 295/75R22.5 or 275/80R22.5.
    b. CRR <5.1 kg/metric ton (In addition, the CRR for trailer tires in
     GEM should be updated to 5.0 kg/metric ton.).
    c. Broken in per section 8.1 of SAE J1263.
    d. Pressure per section 8.5 of SAE J1263.
    e. No uneven wear.
    f. No re-treads.
    g. Should these tires or appropriate Smart Way tires not be
     available, the Administrator testing may include tires used by the
     manufacturer for certification.
------------------------------------------------------------------------
Test Conditions:
    1. Tractor-trailer gap: 45 inches +/- 2.0 inches.
    2. King pin setting: 36 inches +/- 0.5 inches from front of trailer
     to king pin center line.
    3. Trailer ride height: 115 inches +/- 1.0 inches from top of
     trailer to fifth wheel plate, measured at the front of the trailer,
     and set within trailer height boundary from ground as described
     above.
    4. Mudflaps: Positioned immediately following wheels of last axle.
------------------------------------------------------------------------

       Table V-3--Reference Method Coastdown Test Track Condition
                             Specifications
------------------------------------------------------------------------
               Parameter                              Range
------------------------------------------------------------------------
Coastdown speed range..................  70 mph to 15 mph.
Average wind speed at the test site      <10 mph.
 (for each run in each direction).
Maximum wind speed (for each run in      <12.3 mph.
 each direction).
Average cross wind speed (for each run   <5 mph.
 in each direction at the site).
All valid coastdown runs in one          Within 2 standard deviations of
 direction.                               the other valid coastdown runs
                                          in that same direction.

Grade of the test track................  <0.02% or account for the
                                          impact of gravity as described
                                          in SAE J2263 Equation 6.
------------------------------------------------------------------------

         Table V-4--Standard Tanker Trailer for Special Testing
------------------------------------------------------------------------
                                                     Tanker
------------------------------------------------------------------------
Length...............................  42 feet  1 foot,
                                        overall.
                                       40 feet  1 foot,
                                        tank.
Width................................  96 inches  2.
Height...............................  140 inches (overall, from
                                        ground).
Capacity.............................  7,000 gallons.
Suspension...........................  Any (see ``trailer ride height''
                                        below).
Tank.................................  Generally cylindrical with
                                        rounded ends.
Bogie................................  Tandem axle (std). Set to
                                        furthest rear position.
Skin.................................  Generally smooth.
Structures...........................  (1) Centered, manhole (20 inch
                                        opening), (1) ladder generally
                                        centered on side, (1) walkway
                                        (extends lengthwise).
Wheels...............................  24.5 inches. Duals.
Tanker Operation.....................  Empty.
------------------------------------------------------------------------

    Table V-5--Standard Flatbed Reference Trailer for Special Testing
------------------------------------------------------------------------
                                                    Flatbed
------------------------------------------------------------------------
Length...............................  53 feet.
Width................................  102 inches.
Flatbed Deck Heights.................  Front: 60 inches  \1/
                                        2\ inch.
                                       Rear: 55 inches  \1/
                                        2\ inch.
Wheels/Tires.........................  22.5 inch diameter tire with
                                        steel or aluminum wheels.
Bogie................................  Tandem axles, may be in
                                        ``spread'' configuration up to
                                        10 feet  2 inches.
                                       Air suspension.
------------------------------------------------------------------------
Load Profile: 25 inches from the centerline to either side of the load;
Mounted 4.5 inches above the deck.
Load height 31.5 inches above the load support.

    Regardless of the method, all testing using high-roof sleepers
should be performed with a tractor-trailer combination to mimic real
world usage. Accordingly, it is important to match the type of tractor
with the correct trailer. Although, as discussed elsewhere in this
rulemaking, the correct tractor-trailer combination is not always
present or tractor-only operation may occur, the majority of operation
in the real world involves correctly matched tractor-trailer
combinations and we will attempt to reflect that here. Therefore, when
performing an aerodynamic assessment for a Class 7 and 8 tractor with a
high roof, a standard box trailer must be used.
    The definitions of the standard trailer are further detailed in
Sec.  1037.501(g). This ensures consistency and continuity in the
aerodynamic assessments, and maintains the overlap with real world
operation. As mid-roof and low-roof coastdown testing will be conducted
without the trailer if the aerodynamic bin is not extrapolated from a
high-roof version, then testing using other methods should also be
conducted based on the tractor alone.
(e) Standardized Criteria for Aerodynamic Assessment Methods
(i) Coastdown Procedure Requirements
    For coastdown testing, the test runs should be conducted in a
manner consistent with SAE J1263 with additional modifications as
described in the 40 CFR part 1066, subpart C, and in Chapter 3 of the
RIA using the mixed model analysis method. Since the coastdown
procedure is the primary aerodynamic assessment method, the
manufacturer would be required to conduct the coastdown procedure
according to the requirements in this final action and supply the
following information to the agency for approval:
     Facility information: name and location, description and/
or background/history, equipment and capability, track and facility
elevation, track grade and track size/length;
     Test conditions for each test result including date and
time, wind speed and direction, ambient temperature and humidity,
vehicle speed, driving distance, manufacturer name, test vehicle/model
type, model year, applicable model engine family, tire type and rolling
resistance, test weight and driver name(s) and/or ID(s);
     Average Cd result as calculated in 40 CFR
1037.520(b) from valid tests including, at a minimum, ten valid test
results, with no maximum number, standard deviation, calculated error
and error bands, and total number of tests, including number of voided
or invalid tests.
(ii) Wind Tunnel Testing Requirements
    Wind tunnel testing would conform to the following procedures and
modifications, where applicable, including:
     SAE J1252, ``SAE WIND TUNNEL TEST PROCEDURE FOR TRUCKS AND
BUSES'' (July 1981) shall be followed with the following exceptions:
section 5.2 is modified to specify a minimum Reynold's number
(Remin) of 1.0x10\6\ and your model frontal area at zero yaw
angle may exceed the recommended 5 percent of the active test section
area, provided it does not exceed 25 percent;

section 6.0 is modified to add the requirement that, for reduced-scale
wind tunnel testing, a one-eighth (\1/8\th) or larger scale model of a
heavy-duty tractor and trailer must be used; for reduced-scale wind
tunnel testing, section 6.1 is modified to add the requirement that the
model be of sufficient design to simulate airflow through the radiator
inlet grill and across an engine geometry representative of those
commonly in your test vehicle.;
     J1594, ``VEHICLE AERODYNAMICS TERMINOLOGY'' (December
1994); and
     J2071, ``AERODYNAMIC TESTING OF ROAD VEHICLES--OPEN THROAT
WIND TUNNEL ADJUSTMENT'' (June 1994).
    In addition, the wind tunnel used for aerodynamic assessment would
be a recognized facility by the Subsonic Aerodynamic Testing
Association. If your wind tunnel is not capable of testing in
accordance with these EPA modified SAE procedures, you may request EPA
approval to use this wind tunnel and must demonstrate that your
alternate test procedures produce data sufficiently accurate for
compliance. This must be approved by EPA prior to method validation and
correlation factor development. We are finalizing the provisions that
manufacturers that perform wind tunnel testing do so based on the
requirements detailed in this action. The wind tunnel tests should be
conducted at a zero yaw angle and, if so equipped, utilizing the
moving/rolling floor (i.e., the moving/rolling floor should be on
during the test as opposed to static) for comparison to the coastdown
procedure, which corrects to a zero yaw angle for the oncoming wind.
However, manufacturers may be required to test at yaw angles other than
zero (e.g., positive and negative six) if they voluntarily seek to
improve their GHG emissions score for a given model using additional
yaw sweep.
    The manufacturer is required to supply the following:
     Facility information: Name and location, description and
background/history, layout, wind tunnel type, diagram of wind tunnel
layout, structural and material construction;
     Wind tunnel design details: Corner turning vane type and
material, air settling, mesh screen specification, air straightening
method, tunnel volume, surface area, average duct area, and circuit
length;
     Wind tunnel flow quality: Temperature control and
uniformity, airflow quality, minimum airflow velocity, flow uniformity,
angularity and stability, static pressure variation, turbulence
intensity, airflow acceleration and deceleration times, test duration
flow quality, and overall airflow quality achievement;
     Test/Working section information: Test section type (e.g.,
open, closed, adaptive wall) and shape (e.g., circular, square, oval),
length, contraction ratio, maximum air velocity, maximum dynamic
pressure, nozzle width and height, plenum dimensions and net volume,
maximum allowed model scale, maximum model height above road, strut
movement rate (if applicable), model support, primary boundary layer
slot, boundary layer elimination method and photos and diagrams of the
test section;
     Fan section description: Fan type, diameter, power,
maximum rotational speed, maximum top speed, support type, mechanical
drive, sectional total weight;
     Data acquisition and control (where applicable):
Acquisition type, motor control, tunnel control, model balance, model
pressure measurement, wheel drag balances, wing/body panel balances,
and model exhaust simulation;
     Moving ground plane or Rolling Road (if applicable):
Construction and material, yaw table and range, moving ground length
and width, belt type, maximum belt speed, belt suction mechanism,
platen instrumentation, temperature control, and steering; and
     Facility correction factors and purpose.
(iii) CFD Requirements
    Currently, there is no existing standard, protocol or methodology
governing the use of CFD. Therefore, we are establishing a minimum set
of criteria based on today's practices and coupling the use of CFD with
empirical measurements from coastdown and, for gaining innovative
technology credits, wind tunnel procedures. Since there are primarily
two-types of CFD software code, Navier-Stokes based and Lattice-
Boltzman based, we are outlining two sets of criteria to address both
types. Therefore, the agencies are requiring that manufacturers use
commercially-available CFD software code with a turbulence model
included or available. Further details and criteria for each type of
commercially-available CFD software code follows immediately and
general criteria for all CFD analysis are subsequently described.
    For Navier-Stokes based CFD code, manufacturers must perform an
unstructured, time-accurate analysis using a mesh grid size with total
volume element count of at least fifty million cells of hexahedral and/
or polyhedral mesh cell shape, surface elements representing the
geometry consisting of no less than six million elements and a near
wall cell size corresponding to a y+ value of less than three hundred
with the smallest cell sizes applied to local regions of the tractor
and trailer in areas of high flow gradients and smaller geometry
features. Navier-Stokes-based analysis should be performed with a
turbulence model (e.g., k-epsilon (k-[egr]), shear stress transport k-
omega (SST k-[ohgr]) or other commercially-accepted method) and mesh
deformation (if applicable) enabled with boundary layer resolution of
+/- 95 percent. Finally, Navier-Stokes based CFD analysis for the
purposes of determining the Cd should be performed once result
convergence is achieved. Manufacturers should demonstrate convergence
by supplying multiple, successive convergence values.
    For Lattice-Boltzman based CFD code, manufacturers must perform an
unstructured, time-accurate analysis using a mesh grid size with total
number of volume elements of at least fifty million with a near wall
cell size of no greater than six millimeters on local regions of the
tractor and trailer in areas of high flow gradients and smaller
geometry features, with cell sizes in other areas of the mesh grid
starting at twelve millimeters and increasing in size from this value
as the distance from the tractor-trailer model increases.
    In general for CFD, all analysis should be conducted using the
following conditions: A tractor-trailer combination using the
manufacturer's tractor and the trailer according to the trailer
specifications in this regulation, an environment with a blockage ratio
of less than or equal to 0.2 percent to simulate open road conditions,
a zero degree yaw angle between the oncoming wind and the tractor-
trailer combination, ambient conditions consistent with the modified
coastdown test procedures outlined in this regulation, open grill with
representative back pressures based on data from the tractor model,
turbulence model and mesh deformation enabled (if applicable), and
tires and ground plane in motion consistent with and simulating a
vehicle moving in the forward direction of travel. For any CFD
analysis, the smallest cell size should be applied to local regions on
the tractor and trailer in areas of high flow gradients and smaller
geometry features (e.g., the a-pillar, mirror, visor, grille and
accessories, trailer leading and trailing edges, rear bogey, tires,
tractor-trailer gap).
    Finally, with administrator approval, a manufacturer may request
and

perform CFD analysis using parameters and criteria other than stated
above if the manufacturer can demonstrate that the conditions above are
not feasible (e.g., insufficient computing power to conduct such
analysis, inordinate length of time to conduct analysis, equivalent
flow characteristics with more feasible criteria/parameters) or
improved criteria may yield better results (e.g., different mesh cell
shape and size). A manufacturer must provide data and information that
demonstrates that their parameters/criteria will provide a sufficient
level of detail to yield an accurate analysis including comparison of
key characteristics between the manufacturer's criteria/parameters and
those stated above (e.g., pressure profiles, drag build-up, and/or
turbulent/laminar flow at key points on the front of the tractor and/or
over the length of the tractor-trailer combination).
Alternative Aerodynamic Method Comparison to the Coastdown Test
Procedure Reference Method
    If a manufacturer uses any alternative aerodynamic method, or any
method other than the coastdown reference method, the manufacturer
would have to provide a comparison to the coastdown test procedure
reference method. The manufacturer would be required to perform the
alternative aerodynamic method and the coastdown test procedure
reference method on the same model and compare the Cd results. The
alternative aerodynamic method, or any other method using good
engineering judgment, and the coastdown test procedure reference method
must be conducted under similar test conditions and adhere to the
criteria discussed above for each aerodynamic assessment method.
    This demonstration would be performed in the initial year of rule
implementation and would require agency review and approval prior to
use of the alternative aerodynamic method in future years and for other
models.
    The comparison would occur on one model of the manufacturer's
highest sales volume, Class 8, high roof, sleeper cab family with a
full aerodynamics package, either equipped at the factory or sold
through a dealer specifically for that model as an OEM part. If the
manufacturer does not have such a model, the manufacturer may select a
comparable model in that family or a model from another highest sales
volume family in the manufacturer's fleet.
    For the comparison, the manufacturer would be required to provide
information on the test conditions for each test result including but
not limited to: test date and time, wind speed (if applicable),
temperature, humidity, manufacturer and model, model year, applicable
model engine family, tire type and rolling resistance for actual model,
model test weight, equivalent vehicle test weight, actual and simulated
or equivalent vehicle speed, Reynolds number (if applicable), yaw angle
(if applicable), blockage ratio, either calculated or measured (if
applicable), model mounting (if applicable), model geometry, body axis
force and moments (if applicable), total test duration, test vehicle
and type and operator name(s) and/or ID(s). In addition, the
manufacturer must provide the Cd results from valid tests.
    Once the comparison is performed in the initial year, the
manufacturer is required to perform this comparison every three years
on the highest sales volume, Class 8, high roof, sleeper cab family
equipped with a full aerodynamics package unless any or all of the
following occurs: the Class 8, high roof, sleeper cab family/model used
for the original comparison is no longer commercially available, and/or
significantly redesigned, with the meaning of ``significantly'' based
on good engineering judgment, a fundamental change is made to the
current alternative aerodynamic method (e.g., change from facility A to
facility B as a source), and/or the alternative aerodynamic method is
changed to something other than the coastdown test procedure reference
method (e.g., switch to wind tunnel testing from coastdown, change wind
tunnel testing facilities or CFD software code). However, the agency
reserves the right and has the authority under the Clean Air Act (CAA)
to request and have the manufacturer perform a comparison in any year
and on any model that the manufacturer has certified.
    Finally, the data generated for the purpose of this comparison can
be used in annual certification for that model, also called the base
model, and for determining Cd for other models and/or sub-families in
the base model family, or other families in the manufacturer's fleet.
Annual Certification Data Submittal for Aerodynamic Assessment
    For each model in the manufacturer's fleet, the manufacturer is
required to supply aerodynamic information on an annual basis to the
agencies in their certification application. Once the manufacturer has
performed the coastdown test procedure or the comparison for an
alternative aerodynamic method, the aerodynamic assessment method can
be used to generate Cd values for all models the
manufacturer plans to certify and introduce into commerce. For each
model, the manufacturer would determine a predicted aerodynamic drag
(Cd times the frontal area, A). This reduces burden on the
manufacturer to perform aerodynamic assessment but provides data for
all the models in a manufacturer's fleet. If a manufacturer has
previously performed aerodynamic assessment on the other models, the
manufacturer may submit an experimental Cd in lieu of a
predicted Cd.
    The aerodynamic assessment data will be used in one of two ways:
the manufacturer will use the Cd (times A) values to
determine the correct GEM input according to agency-defined tables, or
the agencies will use the manufacturer's input data into the model and
assign a GHG value/score.
    Since the agencies may input the data into the model, manufacturers
are required to provide the information from the coastdown test
procedure, alternative aerodynamic method or the method comparison
described above for annual certification. In addition, the manufacturer
would supply manufacturer fleet information to the agency for annual
certification purposes along with the acceptance demonstration
parameters: manufacturer name, model year, model line (if different
than manufacturer name), model name, engine family, engine
displacement, transmission name and type, number of axles, axle ratio,
vehicle dimensions, including frontal area, predicted or measured
coefficient of drag, assumptions used in developing the predicted or
measured Cd, justification for carry-across of aerodynamic
assessment data, photos of the model line-up, if available, and model
applications and usage options.
    Finally, the agencies reserve the right to request that a
manufacturer generate or provide additional data, prior to
certification, to support and receive annual certification approval.
(f) Aerodynamic Validation and Compliance Audit
    The agencies reserve the right to perform aerodynamic validation
and compliance audit of the manufacturer's aerodynamic results. The
agencies may conduct a vehicle confirmatory evaluation using a vehicle
recruited from the in-use fleet and performing the reference method,
coastdown test procedures, either at the manufacturer's facility or an
independent facility using the agencies equipment and tools. If there
is a discrepancy between the

manufacturer's data submitted for certification and the agencies'
validation results, the agency may perform a full audit of the
manufacturer's source data and aerodynamic assessment methods and tools
used by the manufacturer to produce the data. The manufacturer would be
required to make all equipment and tools available to the agencies to
conduct the full audit.
    Based on this audit, the agencies may require the manufacturer to
make changes to their aerodynamic assessment methods ranging from minor
adjustments to method criteria to switching allowed aerodynamic
assessment methods. For the purposes of aerodynamic validation and
compliance audit, manufacturers will be allowed an additional
compliance margin of one bin from the certified bin for the model
evaluated (e.g., if a manufacturer certifies a model to Bin IV, the
results of the aerodynamic valid/compliance audit must fall within the
next highest bin, in this case Bin III). In addition, the agencies may
select any model from the manufacturer's fleet/vehicle family to
perform the aerodynamic validation and compliance.
(g) Aerodynamic Bin Category Adjustment Using Yaw Sweep Information
    As discussed in Section II.B.2, the agencies are finalizing
aerodynamic drag values which represent zero degree yaw (i.e.,
representing wind from directly in front of the vehicle, not from the
side). We recognize that wind conditions, most notably wind direction,
have a greater impact on real world CO2 emissions and fuel
consumption of heavy-duty trucks than of light-duty vehicles. To
provide additional incentive for manufacturers using aerodynamic
techniques (i.e., techniques that use assessment at yaw angles more or
less than zero degrees to capture the influence of side winds and
calculate wind average drag coefficient), the agencies are defining an
approach to allow manufacturers to account for improved aerodynamic
performance in crosswind conditions similar to those experienced by
vehicles in use. If a manufacturer can benefit from having a model that
performs in regimes or conditions other than the scope of the test
parameters in this rulemaking, this creates an incentive for the entire
industry. As a result, we are allowing manufacturers to use the
coefficient of drag values at positive six, negative six, and zero
degrees yaw to improve their GHG score.
    The Yaw Sweep Adjustment would be determined using the following
steps and equations:
     Step 1: Determine your aero method adjustment factor as
described above in paragraph (d) of this section and using the
equation;
[GRAPHIC] [TIFF OMITTED] TR15SE11.005

     Step 2: Apply the aerodynamic method adjustment factor to
the positive six, negative six and zero degrees yaw Cd values for that
model using the equation;

Cd Adjusted = Adjustment Factor x
Cd(+6 degrees/-6 degrees/0 degrees, model)

     Step 3: Calculate your Adjusted zero yaw Cd*A

Adjusted Zero Yaw Cd*A(model) = adjusted +/- Six Yaw
Cd(average,model) *A(model) x Zero Yaw Cd*A(industry
average) +/-Six Yaw Cd(average)*A(industry average)

     Step 4: Use the adjusted zero yaw Cd*A for the model to
determine appropriate bin and the associated Cd input for the GEM to
determine your Yaw Sweep Adjusted GHG score.
    Essentially, this equation becomes y = x * C where y is the
adjusted zero yaw Cd, x is the corrected average of the +/- six degree
yaw Cds for the manufacturer's model, and C is a constant value based
on the ratio of the zero yaw Cd and WACd ratio for the industry. The
current default value for this industry baseline ratio for this is
rulemaking is 0.8065 based on the Cd values of current Class 8, high-
roof, aero sleeper cab models in the fleet. The agencies may
periodically review this industry baseline ratio and adjust it, if
necessary, with notification to the industry.
    The yaw sweep adjustment described above only applies to Class 7,
high-roof day cab and Class 8 high-roof day or sleeper cab tractors and
a manufacturer seeking yaw sweep adjustment must use an approved,
alternative aerodynamic method to generate the yaw sweep data.
Manufacturers may use a more yaw sweep angles (e.g., zero, +/- 1, 3, 6,
9) for their yaw sweep adjustment and, in this case, must calculate the
wind-average Cd (WACd) according to SAE J1252 and use this value in
lieu of the average of the +/- six degree yaw Cds in the equations
above.
    As stated elsewhere in this regulation, the Agencies reserve the
right to review a manufacturer's proposed adjustment and discuss the
proposed adjustment with the manufacturer. The Agencies will notify the
manufacturer of the need for a review and the manufacturer must provide
all information requested by the Agencies to support the review and
subsequent discussion(s). The agencies also reserve the right to deny
aerodynamic bin category adjustment independent or as a result of the
review/discussions with the manufacturer. In such case, the Agencies
will notify the manufacturer of denial prior to certification to ensure
the proper inputs to the GEM are used.
(4) Compliance Reports
(a) Early Model Year Data
    The regulatory text of the NPRM included specifications for
manufacturers to submit pre-certification compliance reports for each
of a manufacturer's fleet of heavy-duty tractors. Navistar and Volvo
commented that the requirements specified in the NHTSA pre-
certification reports are overbroad and should be eliminated. The pre-
certification reports included requirements for manufactures to submit
a wide variety of information on these vehicles. The variety of
information was believed to be necessary given that these vehicles had
no previous compliance information for meeting fuel efficiency and
emission standards and the agencies wanted to ensure that enough
information was obtain to ensure sufficient compliance with the
program. The agencies have since reviewed the level of detail required
in the precertification reports and are in agreement with commenters
that the required information may be overly broad for compliance
purposes and given that this is the first time these manufacturers have
been regulated, the level of information required may not be available
until subsequent model years. Therefore, as discussed previously for
pickup trucks and vans, the agencies have removed the requirement for

manufactures to submit pre-certification compliances reports for these
classes of vehicles.
    As an alternative to receiving early compliance model year
information in the precertification reports, the agencies have decided
to use manufacturer's application for certificates of conformity to
obtain early model estimates. Currently, the applications for
certificates are not required to include the fuel consumption
information required by NHTSA. Therefore, the agencies are adopting
provisions in the final rules for manufacturers to provide emission and
equivalent fuel consumption estimates in the manufacturer's
applications for certification. The agencies will treat information
submitted in the applications as a manufacturer's demonstration of
providing early compliance information, similar to the pre-model year
report submitted for heavy-duty pickup trucks and vans. The final rule
establishes a harmonized approach by which manufacturers will submit
applications through an EPA-administered database, such as the Verify
system, as the single point of entry for all information required for
this national program and both agencies will have access to the
information. If by model year 2012, the agencies are not prepared to
receive information through the EPA Verify database system,
manufacturers are expected to submit written applications to the
agencies. This approach should streamline this process and reduce
industry burden and provide sufficient information for the agencies to
carry out their early compliance activities.
(b) Final Reports
    The NPRM proposed for manufacturers participating in the ABT
program to provide EOY and final reports. The EOY reports for the ABT
program were required to be submitted by manufacturers no later than 90
days after the calendar year and final report no later than 270 days
after the calendar year.\318\ Manufacturers not participating in the
ABT program were required to provide an EOY report within 45 days after
the calendar year but no final reports were required. The final ABT
report due was established coinciding with EPA's existing criteria
pollutant report for heavy-duty engines. The EOY report was required in
order to receive preliminary final estimates and identifies
manufacturers that might have a credit deficit for the given model
year. Manufacturers with a credit surplus at the end of each model
could receive a waiver from providing EOY reports. As proposed, the
remaining manufacturers were required to submit reports to EPA and send
copies of those reports to NHTSA with equivalent fuel consumption
values.
---------------------------------------------------------------------------

    \318\ Corresponding to the compliance model year.
---------------------------------------------------------------------------

    In response to the NPRM, commenters recommended collecting
additional data. One commenter requested collecting information to
develop and refine test cycles that more accurately reflect actual
driving cycles for medium- and heavy-duty trucks. Several other
commenters (ACEE, Eaton, CALSTART, NRDC and UCS) recommended collecting
advanced data on in-service vehicles and that the collected data be
analyzed and characterized for each vocational application, especially
for hybrid vehicles, in a cooperative government and industry effort.
Commenters (ACEE, DTNA, NRGDC, UCS and Volvo) also requested that the
agency's data collection ensure to include information on actual
vehicle configurations sold in the fleet.
    Many commenters argued against the burden placed upon the industry
in meeting the agencies' proposed required reporting provisions. One
commenter argued against providing actual production information due to
the variability that exists in building heavy-duty vehicles and in the
influence of changing fleet interest each year indicating that only
estimated information should have to be provided. Commenters (Volvo and
Navistar) generally objected stating that the agency requirements in
its reports are both unnecessary and overly burdensome. Comments in
response to the NPRM requested that for manufacturers not using ABT
provisions, the EOY report due 45 days after the end of the calendar
year should be combined with the ABT report due 90 days after the same
model year. Commenters also requested that the exempted off-road
vehicle report be consolidated with the EOY report. Other concerns
raised by commenters were for the agencies to remove any differences in
reporting provisions and implement a single uniform reporting template
that manufacturers can submit to both agencies.
    One commenter (Volvo) requested that the agencies simplify the
reporting requirements for vehicle configurations in both the EOY and
final reports, commenting that the proposal as outlined was extremely
burdensome to vehicle manufacturers. The NPRM regulation stated that
the manufacturer must identify each distinguishable vehicle
configuration in the vehicle family or sub-family and identification of
FELs for each subfamily. The regulation calls for reporting of results
and modeling inputs for each subfamily. The commenter believed that the
burden of meeting these requirements for the vast number of families/
subfamilies is substantial and unjustified. For this commenter, there
is a potential for almost 45 million sub-families in the vocational and
tractor categories. This approach should reduce the number of vehicle
families to an amount that is suitable for reporting. The BlueGreen
Alliance and ACEEE also requested the agencies to implement a program
as part of the final rule to collect data, actual vehicle
configurations sold and their performance as estimated by simulation
modeling, which will provide information required to develop a full-
vehicle program in the future.
    For the final rules, the agencies are requiring EOY and final
reports, as proposed. However, the agencies will consolidate the
reporting as requested by comments and is requiring equivalent fuel
consumption information for all reports submitted to EPA. The final
rules establish a harmonized approach by which manufacturers will
submit reports through an EPA-administered database, such as the Verify
system, as the single point of entry for all information required for
this national program and both agencies will have access to the
information. If by model year 2012, the agencies are not prepared to
receive information through the EPA Verify database system,
manufacturers are expected to submit written reports to the agencies.
The agencies are also combining the EOY reports for manufacturers not
using ABT provisions with other EOY reports and are requiring a
submission date 90 days after the calendar year. The agencies view the
adopted requirements in the final rules for EOY and final reports will
provide sufficient data requests to satisfy these requests. The
agencies also agree with Volvo's concerns and have adopted a new
classification system for selecting vehicle families as described
elsewhere in this section. A summary of the required information in the
final rules for EOY and final reports is as follows:
     Vehicle family designation and averaging set.
     Vehicle emissions and fuel consumption standards including
any alternative standards used.
     Vehicle family FELs.
     Final production volumes.
     Certified test cycles.
     Useful life values for vehicle families.

     A credit plan identifying the manufacturers actual credit
balances, credit flexibilities, credit trades and a credit deficit plan
if needed demonstrating how it plans to resolve any credit deficits
that might occur for a model year within a period of up to three model
years after that deficit has occurred.
     A plan describing the vehicles that were exempted such as
for off-road or small business purposes.
     A plan describing any alternative fueled vehicles that
were produced for the model year identifying the approaches used to
determinate compliance and the production volumes.
(c) Additional Required Information
    Throughout the model year, manufacturers may be required to report
various submissions to the agencies to comply with various aspects of
the rules. These requests have differing criteria for submission and
approval. Table V-6 below provides a summary of the types of
submission, required submission dates and the EPA and NHTSA regulations
that apply. The agencies will review and grant requests considering the
timeliness of the submissions and the completeness of the requests.

                            Table V-6--Summary of Required Information for Compliance
----------------------------------------------------------------------------------------------------------------
                                                                                NHTSA
            Submission                    Applies to        Required submissions  EPA regulation    regulation
                                                                    date             reference       reference
----------------------------------------------------------------------------------------------------------------
Small business exemptions.........  Vehicle manufacturers  Before introducing               Sec.    Sec.   535.8
                                     meeting the Small      any excluded vehicle        1037.150
                                     Business               into U.S. commerce.
                                     Administration (SBA)
                                     size criteria of a
                                     small business as
                                     described in 13 CFR
                                     121.201.
Incentives for early introduction.  The provisions apply   EPA must be notified             Sec.    Sec.   535.8
                                     with respect to        before the                  1037.150
                                     tractors and           manufacturer submits
                                     vocational vehicles    its applications for
                                     produced in model      certificates of
                                     years before 2014.     conformity.
Voluntary compliance for NHTSA      Vehicle manufacturers  NHSAT must be                      NA    Sec.   535.8
 standards.                          seeking early          notified before the
                                     compliance in model    manufacturer submits
                                     years 2014 to 2016.    its applications for
                                                            certificates of
                                                            conformity.
Approval of alternate methods to    Tractors meeting Sec.  EPA must be notified             Sec.    Sec.   535.8
 determine drag coefficients.          1037.106.            before the                  1037.150
                                                            manufacturer submits
                                                            its applications for
                                                            certificates of
                                                            conformity.
Off-road exemption................  Manufacturers wanting  EPA must be notified             Sec.    Sec.   535.8
                                     to exclude tractors    before the                  1037.150
                                     from vehicle           manufacturer submits
                                     standards.             its applications for
                                                            certificates of
                                                            conformity.
Vocational Tractor................  Manufacturers wanting  EPA must be notified             Sec.    Sec.   535.8
                                     to reclassify          before the                  1037.150
                                     tractor as             manufacturer submits
                                     vocational tractors    it applications for
                                     making them            certificates of
                                     applicable to          conformity.
                                     vocational vehicle
                                     standards.
Exemption from EOY reports........  Manufactures with      90-days after the                Sec.    Sec.   535.8
                                     surplus credits at     calendar year ends.         1037.730
                                     the end of the model
                                     year.
----------------------------------------------------------------------------------------------------------------

E. Class 2b-8 Vocational Vehicles

(1) Final Compliance Approach
    Like Class 7 and 8 combination tractors, heavy-duty vocational
vehicles will be required to have both engine and chassis certificates
of conformity. As discussed in the engine certification section,
engines that will be used in vocational vehicles would need to be
certified using the heavy-duty FTP cycle for GHG pollutants and show
compliance through the useful life of the engine. This certification is
in addition to the current requirements for obtaining a certificate of
conformity for criteria pollutant emissions.
    For this final action, the majority of the GHG reduction for
vocational vehicles is expected to come from the use of LRR tires as
well as increased utilization of hybrid powertrain systems. Other
technologies such as aerodynamic improvements and vehicle speed
limiting systems are not as relevant for this class of vehicles, since
the typical duty cycle is much more urban, consisting of lower speeds
and frequent stopping. Idle reduction strategies are expected to be
encompassed by hybrid technology, which we anticipate will ultimately
handle PTO operation as well. Therefore, for this final action,
certification of heavy-duty vocational vehicles with conventional
powertrains will focus on quantifying GHG benefits due to the use of
LRR tires through the GEM.
(a) Certification Process
    Vehicles will be divided into vehicle families for purposes of
certification. As with Class 7 and 8 combination tractors, these are
groups of vehicles within a given regulatory subcategory that are
expected to share common emission characteristics. Vocational vehicle
regulatory subcategories share the same structure as those used for
heavy-duty engine criteria pollutant certification and are based on
GVWR. This includes light-heavy (LHD) with a GVWR at or below 19,500
pounds, medium-heavy (MHD) with a GVWR above 19,500 pounds and at or
below 33,000 pounds, and heavy-heavy (HHD) with a GVWR above 33,000
pounds. We anticipate manufacturers will have one vehicle family per
regulatory subcategory, however hybrid vehicles will need to be
separated into additional unique vehicle families. Manufacturers may
also subdivide families into sub-families if GHG emissions performance
is expected to change significantly within the vehicle family. As with
Class 7 and 8 combination tractors, we anticipate using the
standardized 12-digit naming convention to identify vocational vehicle
families. As with engines and Class 7 and 8 combination tractors, each
certifying vehicle manufacturer would have a unique three digit code
assigned to them. Currently, there is no 5th digit (industry sector)
code for this class of vehicles and EPA will issue an update to the
current guidance explaining which character(s) should be used for
vocational vehicles. The agencies originally proposed that engine
displacement be included in the vehicle family name, however the wide
range of engines available across most regulatory

subcategories makes this requirement irrelevant and unnecessary at the
time of this rulemaking. Therefore, we are reserving the remaining
characters for California ARB and/or manufacturer use, such that the
result is a unique vehicle family name.
    Each vehicle family must demonstrate compliance with emission
standards using the GEM. GEM inputs for conventional (i.e. non-hybrid)
vocational vehicles primarily involves entering tire rolling resistance
information. Additional provisions are available for certification of
hybrid vehicles or vehicles using other advanced or innovative
technologies, as detailed in Section IV. If the vehicle family consists
of multiple configurations, only results from the worst-case
configuration are necessary for certification in addition to an
engineering evaluation demonstrating that the modeled configuration
indeed reflects the worst-case configuration. If the vehicle family is
divided into subfamilies, unique GEM results are required for at least
one configuration per subfamily.
    The agencies have received comments from engine manufacturers,
truck manufacturers, and hybrid system manufacturers raising concerns
regarding the duty cycles and the weighting factors proposed for
evaluating transient applications. The agencies proposed three methods
for evaluating hybrid system performance in an effort to generate
credits. The proposed duty cycles considered for the proposal will
continue to be used with this final action. The Agencies proposed a
transient duty cycle, a 55 mile-per-hour steady state cruise and a 65
mile per hour steady state cruise. The transient duty cycle, is
essentially the same transient cycle proposed in the NPRM with the
exception that it minimizes inappropriate shift events. Additionally,
the steady state cycles proposed by the Agencies remain essentially
unchanged. In response to concerns raised by engine manufacturers and
hybrid system manufacturers regarding the operation of vehicles most
likely to be hybridized in the near term, we are modifying the
weighting factors for each cycle to address the distribution of the
emissions impact associated with each duty cycle. The weighting factors
will be changed such that a greater emphasis on the type of transient
activity seen as more characteristic of hybrid applications will be
evident. The new weighting factors between duty cycles for hybrid
certification will be 75 percent for the transient, 9 percent for the
55 mph cruise cycle, and 16 percent for the 65 mph cruise cycle. The
basis for this change may be seen in the memorandum to Docket EPA-HQ-
OAR-2010-0162, which describes the data set used to describe real world
vehicle performance. In addition to this modification, the Power-Take-
Off (PTO) operation will be characterized for vehicles utilizing a PTO
system for which there is a benefit for use of the hybrid technology.
The testing provisions for the comparison in the A to B testing for
complete vehicle or post-transmission powerpack testing may be seen in
40 CFR 1037.525. The testing provisions for work-specific pre-
transmission evaluation using an engine based approach may be seen in
40 CFR 1036.525.
(b) Demonstrating Compliance With the Final Standards
(i) CO2 and Fuel Consumption Standards
Model
    As stated above, the technology basis for the final standards for
vocational vehicles is use of LRR tires. Similar to Class 7 and 8
combination tractors, compliance with the standards will be
demonstrated using the GEM predictive model. However, the input
parameters entered by the vehicle manufacturer would be limited to the
properties of the tires. The GEM will use the tire data, along with
inputs reflecting a baseline truck and engine, to generate a complete
vehicle model. The test weight used in the model will be based on the
vehicle class, as identified above. Light-heavy-duty vehicles will have
a test weight of 16,000 pounds; 25,150 pounds for medium heavy-duty
vehicles; and heavy heavy-duty vocational vehicles will use a test
weight of 67,000 pounds. The model would then be exercised over the
HHDDT transient cycle as well as 55 and 65 mph steady-state cruise
conditions. The results of each of the three tests would be weighted at
16%, 9%, and 75% for 65 mph, 55 mph, and transient tests, respectively.
Innovative technology credits may be used to demonstrate compliance,
however because the technology would not be an input into GEM,
alternative procedures would be needed to determine the value of the
credit as described in Preamble Section IV.
    It may seem more expedient and just as accurate to require
manufacturers use tires meeting certain industry standards for
qualifying tires as having LRR. In addition, CO2 and fuel
consumption benefits could be quantified for different ranges of
coefficients of rolling resistance to provide a means for comparison to
the standard. However, we believe that as technology advances, other
aspects of vocational vehicles may warrant inclusion in future
rulemakings. For this reason, we remain committed to having the
certification framework in place to accommodate such additions. While
the modeling approach may seem to be overly complicated for this phase
of the rules, it also serves to create a certification pathway for
future rulemakings and therefore we believe this is the best approach.
Moreover, a design standard would discourage use of alternative
technologies to meet the standard, and otherwise impede desirable
flexibility.
In-use Standards
    The category of wear items primarily relates to tires. It is
expected that vehicle manufacturers will equip their trucks with LRR
tires, since the final vehicle standard is predicated on LRR tire
performance. The tire replacement intervals for this class of vehicle
is normally in the range of 50,000 to 100,000 miles, which means the
owner/operator will be replacing the tires at several points within the
useful life of the vehicle. We believe that as LRR tires become more
common on new equipment, the aftermarket prices of these tires will
also decrease. Along with decreasing tire prices, the fuel savings
realized through use of LRR tires will ideally provide enough incentive
for owner/operators to continue purchasing these tires. The inventory
modeling in this rulemaking package reflects the continued use of LRR
tires through the life of the vehicle.
(ii) Evaporative Emission Standards
    Evaporative and refueling emissions from heavy-duty highway engines
and vehicles are currently regulated under 40 CFR part 86. Even though
these emission standards apply to the same engines and vehicles that
must meet exhaust emission standards, we require a separate certificate
for complying with evaporative and refueling emission standards. An
important related point to note is that the evaporative and refueling
emission standards always apply to the vehicle, while the exhaust
emission standards may apply to either the engine or the vehicle. For
vehicles other than pickups and vans, the standards in this program to
address greenhouse gas emissions apply separately to engines and to
vehicles. Since we will be applying both greenhouse gas standards and
evaporative/refueling emission standards to vehicle manufacturers, we
believe it will be advantageous to have the regulations related to
their certification requirements written

together as much as possible. EPA regards these final changes as
discrete, minimal, and for the most part clarifications to the existing
standards. We have not finalized any changes to the evaporative or
refueling emission standards, but we have come across several
provisions that warrant clarification or correction:
 When adopting the most recent evaporative emission change we
did not carry through the changes to the regulatory text applying
evaporative emission standards for methanol-fueled compression-ignition
engine. The final regulations correct this by applying the new
standards to all fuels that are subject to standards.
 We are finalizing provisions to address which standards apply
when an auxiliary (nonroad) engine is installed in a motor vehicle,
which is currently not directly addressed in the highway regulation.
The final approach requires testing complete vehicles with any
auxiliary engines (and the corresponding fuel-system components).
Incomplete vehicles must be tested without the auxiliary engines, but
any such engines and the corresponding fuel system components will need
to meet the standards that apply under our nonroad program as specified
in 40 CFR part 1060.
 We have removed the option for secondary vehicle manufacturers
to use a larger fuel tank capacity than is specified by the certifying
manufacturer without re-certifying the vehicle. Secondary vehicle
manufacturers needing a greater fuel tank capacity will need to either
work with the certifying manufacturer to include the larger tank, or go
through the effort to re-certify the vehicle itself. Our understanding
is that this provision has not been used and would be better handled as
part of certification rather than managing a separate process. We are
also finalizing corresponding changes to the emission control
information label.
 Rewriting the regulations in a new part in conjunction with
the greenhouse gas standards allows for some occasions of improved
organization and clarity, as well as updating various provisions. For
example, we have finalized a leaner description of evaporative emission
families that does not reference sealing methods for carburetors or air
cleaners. We have also clarified how evaporative emission standards
affect engine manufacturers and are finalizing more descriptive
provisions related to certifying vehicles above 26,000 pounds GVWR
using engineering analysis.
 Since we adopted evaporative emission standards for gaseous-
fuel vehicles, we have developed new approaches for design-based
certification (see, for example, 40 CFR 1060.240). We request comment
on changing the requirements related to certifying gaseous-fuel
vehicles to design-based certification. This would allow for a simpler
assessment for certifying these vehicles without changing the standards
that apply.
(2) Final Labeling Provisions
    It is crucial that a means exist for allowing field inspectors to
identify whether a vehicle is certified, and if so, whether it is in
the certified configuration. As with engines and tractors, we believe
an emission control information label is a logical first step in
facilitating this identification. For vocational vehicles, the engine
will have a label that is permanently affixed to the engine and
identify the engine as certified for use in a certain regulatory
subcategory of vehicle (i.e., MHD, etc).
    The vehicle will also have a label listing the manufacturer of the
vehicle, vehicle family (and subfamily, if applicable), regulatory
subcategory, date of manufacture, compliance statement, FEL, and
emission control system identifiers. The required content of this label
is consistent with the label description provided earlier for Class 7
and 8 tractors. Since LRR tires are expected to be the primary means
for vehicles to comply, it is expected that LRR tires will be the only
component identified as part of the emission control system on the
label. For tires to qualify as low rolling resistance (for purposes of
this vocational vehicle label), they need to have a coefficient of
rolling resistance at or below 7.7 kg/metric ton. In addition, if any
other emission related components are present, such as hybrid
powertrains, key components will also need to be specified on the
label. Like the engine label, this will need to be permanently affixed
to the vehicle in an area that is clearly visible to the owner/
operator. At the time of certification, manufacturers will be required
to submit an example of their vehicle emission control label such that
EPA can verify that all critical elements are present. In addition to
the label, manufacturers will also need to describe where the unique
vehicle identification number and date of production can be found on
the vehicle.
(3) Other Certification Issues
Warranty
    As with other heavy-duty engine and vehicle regulatory categories,
vocational vehicle chassis manufacturers would be required to warrant
their product to be free from defects that would result in
noncompliance with emission standards. This warranty also covers the
failure of emission related components for the warranty period of the
vehicle. For vocational vehicles, this primarily applies to tires.
    Manufacturers of chassis for vocational vehicles would be required
to warrant tires to be free from defects at the time of initial sale.
As with Class 7 and 8 combination tractors, we expect the chassis
manufacturer to only warrant the original tires against manufacturing
or design-related defects. This tire warranty would not cover
replacement tires or damage from road hazards or improper inflation.
    As with Class 7 and 8 combination tractors, all warranty
documentation would be submitted to EPA at the time of certification.
This should include the warranty statement provided to the owner/
operator, description of the service repair network, list of covered
components (both conventional and high-cost), and length of coverage.
EPA Certification Fees
    Similar to engine and tractor-trailer vehicle certification, the
agency will assess certification fees for vocational vehicles. The
proceeds from these fees are used to fund the compliance and
certification activities related to GHG regulation for this industry
segment. In addition to the certification process, other activities
funded by certification fees include EPA-administered in-use testing,
selective enforcement audits, and confirmatory testing. At this point,
the exact costs associated with the heavy-duty vehicle GHG compliance
are not well known. EPA will assess its compliance program associated
with this program and assess the appropriate level of fees. We
anticipate that fees will be applied based on certification families,
following the light-duty vehicle approach.
Maintenance
    Vehicle manufacturers are required to outline a maintenance
schedule that ensures the emission control system remains functional
throughout the useful life of the vehicle. For vocational vehicles,
this largely involves ensuring that customers have sufficient
information to purchase replacement tires that meet or exceed original
equipment specifications. As with Class

7 and 8 tractors, we believe that this information should be included
in the owner's manual to the vehicle. This statement must be submitted
to EPA at the time of certification to verify that the customer indeed
has enough information to purchase the correct replacement tires.

F. General Regulatory Provisions

(1) Statutory Prohibited Acts
    Section 203 of the CAA describes acts that are prohibited by law.
This section and associated regulations apply equally to the greenhouse
gas standards as to any other regulated emission. Acts that are
prohibited by section 203 of the CAA include the introduction into
commerce or the sale of an engine or vehicle without a certificate of
conformity, removing or otherwise defeating emission control equipment,
the sale or installation of devices designed to defeat emission
controls, and other actions. In addition, vehicle manufacturers, or any
other party, may not make changes to the certified engine that would
result in it not being in the certified configuration.
    EPA will apply Sec.  86.1854-12 to heavy-duty vehicles and engines;
this codifies the prohibited acts spelled out in the statute. Although
it is not legally necessary to repeat what is in the CAA, EPA believes
that including this language in the regulations provides clarity and
improves the ease of use and completeness of the regulations. Since
this change merely codifies provisions that already apply, there is no
burden associated with the change.
(2) Regulatory Amendments Related to Heavy-Duty Engine Certification
    We are adopting the new engine-based greenhouse gas emissions
standards in 40 CFR part 1036 and the new vehicle-based standards in 40
CFR part 1037. We are continuing to rely on 40 CFR parts 85 and 86 for
conventional certification and compliance provisions related to
criteria pollutants, but the final regulations include a variety of
amendments that will affect the provisions that apply with respect to
criteria pollutants. We are not intending to change the stringency of,
or otherwise substantively change any existing standards.
    The introduction of new parts in the CFR is part of a long-term
plan to migrate all the regulatory provisions related to highway and
nonroad engine and vehicle emissions to a portion of the CFR called
Subchapter U, which consists of 40 CFR parts 1000 through 1299. We have
already adopted emission standards, test procedures, and compliance
provisions for several types of engines in 40 CFR parts 1033 through
1074. We intend eventually to capture all the regulatory requirements
related to heavy-duty highway engines and vehicles in these new parts.
Moving regulatory provisions to the new parts allows us to publish the
regulations in a way that is better organized, reflects updates to
various certification and compliance procedures, provides consistency
with other engine programs, and is written in plain language. We have
already taken steps in this direction for heavy-duty highway engines by
adopting the engine-testing procedures in 40 CFR part 1065 and the
provisions for selective enforcement audits in 40 CFR part 1068.
    EPA sought comment on drafting changes and additions. This
solicitation related solely to the appropriate migration, translation,
and enhancement of existing provisions. EPA did not solicit comment on
the substance of these existing rules, and did not amend, reconsider,
or otherwise re-examine these provisions' substantive effect.
    The rest of this section describes the most significant of these
final redrafting changes. The proposal includes several changes to the
certification and compliance procedures, including the following:
     We are requiring that engine manufacturers provide
installation instructions to vehicle manufacturers (see Sec.
1036.130). We expect this is already commonly done; however, the
regulatory language spells out a complete list of information we
believe is necessary to properly ensure that vehicle manufacturers
install engines in a way that is consistent with the engine's
certificate of conformity.
     Sec.  1036.30, Sec.  1036.250, and Sec.  1036.825 spell
out several detailed provisions related to keeping records and
submitting information to us.
     We wrote the greenhouse gas regulations to divide heavy-
duty engines into ``spark-ignition'' and ``compression-ignition''
engines, rather than ``Otto-cycle'' and ``diesel'' engines, to align
with our terminology in all our nonroad programs. This will likely
involve no effective change in categorizing engines except for natural
gas engines. To address this concern, we are including a provision in
Sec.  1036.150 to allow manufacturers to meet standards for spark-
ignition engines if they were regulated as Otto-cycle engines in 40 CFR
part 86, and vice versa.
     Sec.  1036.205 describes a new requirement for imported
engines to describe the general approach to importation (such as
identifying authorized agents and ports of entry), and identifying a
test lab in the United States where EPA can perform testing on
certified engines. These steps are part of our ongoing effort to ensure
that we have a compliance and enforcement program that is as effective
for imported engines as for domestically produced engines. We have
already adopted these same provisions for several types of nonroad
engines.
     Sec.  1036.210 specifies a process by which manufacturers
are able to get preliminary approval for EPA decisions for questions
that require lead time for preparing an application for certification.
This might involve, for example, preparing a plan for durability
testing, establishing engine families, identifying adjustable
parameters, and creating a list of scheduled maintenance items.
     Sec.  1036.225 describes how to amend an application for
certification.
     We are revising 40 CFR 85.1701 to apply the exemption
provisions described in 40 CFR part 1068 to heavy-duty highway engines
starting in 2014. Manufacturers may optionally use the exemption
provisions from part 1068 earlier. This involves only very minor
changes in the terms and conditions associated with the various types
of exemptions. This change will help us to implement a consistent
compliance program for all engine and vehicle categories. We are
similarly revising 40 CFR 85.1511 to reference the importation-related
exemptions in part 1068 for all motor vehicles and motor vehicle
engines.
     We are finalizing a provision allowing manufacturers to
use the defect reporting provisions of 40 CFR part 1068 instead of
those in 40 CFR part 85. This involves setting thresholds for
investigating and reporting defects based on defect rates rather than
absolute numbers of defects. Once we gain more experience with applying
the defect-reporting provisions in 40 CFR part 1068 for motor vehicles,
we will consider making those provisions mandatory, including any
appropriate adjustments.
    In addition, we are revising 40 CFR 1068.210 and 1068.325 to
address a concern raised by engine manufacturers. The provisions for
importing engines under a temporary exemption disallow selling exempted
engines even though some of the situations addressed depend on engine
sales (such as delegated assembly). We have added clarifying language
to the individual exemptions to describe whether or how engines may be
sold or leased. In the case of the testing exemption in Sec.  1068.210,
this involves a further change to specify how

a manufacturer must track the status and final disposition of exempted
engines or equipment. We are also making a small change to the testing
exemption to remove the administrative step of requiring an exchange of
signed documents for the exemption to be effective. This will
streamline the process for the testing exemption and make it more like
that for other types of exemptions.
(3) Test Procedures for Measuring Emissions From Heavy-Duty Vehicles
    We are finalizing a new part 1066 that contains general chassis-
based test procedures for measuring emissions from a variety of
vehicles, including vehicles over 14,000 pounds GVWR. However, we are
not finalizing application of these procedures broadly at this time.
The test procedures in 40 CFR part 86 continue to apply for vehicles
under 14,000 pounds GVWR. The final part 1066 procedures applies only
for any testing that would be required for larger vehicles. This could
include ``A to B'' hybrid vehicle testing, coastdown testing, and
potentially limited innovative technology testing. Nevertheless, we
will likely consider in the future applying these procedures also for
other heavy-duty vehicle testing and for light-duty vehicles, highway
motorcycles, and/or nonroad recreational vehicles that rely on chassis-
based testing.
    As noted above, engine manufacturers are already using the test
procedures in 40 CFR part 1065 instead of those originally adopted in
40 CFR part 86. The new procedures are written to apply generically for
any type of engine and include the current state of technology for
measurement instruments, calibration procedures, and other practices.
We are finalizing the chassis-based test procedures in part 1066 to
have a similar structure.
    The final procedures in part 1066 reference large portions of part
1065 to align test specifications that apply equally to engine-based
and vehicle-based testing, such as CVS and analyzer specifications and
calibrations, test fuels, calculations, and definitions of many terms.
Since several highway engine manufacturers were involved in developing
the full range of specified procedures in part 1065, we are confident
that many of these provisions are appropriate without modification for
vehicle testing.
    The remaining test specifications needed in part 1066 are mostly
related to setting up, calibrating, and operating a chassis
dynamometer. This also includes the coastdown procedures that are
required for establishing the dynamometer load settings to ensure that
the dynamometer accurately simulates in-use driving.
    Current testing requirements related to dynamometer specifications
rely on a combination of regulatory provisions, EPA guidance documents,
and extensive know-how from industry experience that has led to a good
understanding of best practices for operating a vehicle in the
laboratory to measure emissions. We attempted in this rulemaking to
capture this range of material, organizing these specifications and
verification and calibration procedures to include a complete set of
provisions to ensure that a dynamometer meeting these specifications
would allow for carefully controlled vehicle operation such that
emission measurements are accurate and repeatable.
    The procedures are written with the understanding that heavy-duty
highway manufacturers have, and need to have, single-roll electric
dynamometers for testing. We are aware that this is not the case for
other applications, such as all-terrain vehicles. We are not adopting
specific provisions for testing with hydrokinetic dynamometers, we are
already including a provision acknowledging that we may approve the use
of dynamometers meeting alternative specifications if that is
appropriate for the type of vehicle being tested and for the level of
stringency represented by the corresponding emission standards.
    Drafting a full set of test specifications highlights the mixed use
of units for testing. Some chassis-based standards and procedures are
written based largely on the International System of Units (SI), such
as gram per kilometer (g/km) standards and kilometers per hour (kph)
driving, while others are written based largely on English units (g/
mile standards and miles per hour driving). The proposal includes a mix
of SI and English units with instructions about converting units
appropriately. However, most of the specifications and examples are
written in English units. While this seems to be the prevailing
practice for testing in the United States, we understand that vehicle
testing outside the United States is almost universally done in SI
units. In any case, dynamometers are produced with the capability of
operating in either English or SI units. We believe there would be a
substantial advantage toward the goal of achieving globally harmonized
test procedures if we would write the test procedures based on SI
units. This would also in several cases allow for more straightforward
calculations, and reduced risk of rounding errors. For comparison, part
1065 is written almost exclusively in SI units. We sought comment on
the use of units throughout part 1066. At this time we are not
finalizing changes from our current approach.
    A fundamental obstacle toward using SI units is the fact that some
duty cycles are specified based on speeds in miles per hour. To address
this, it would be appropriate to convert the applicable driving
schedules to meter-per-second (m/s) values. Converting speeds to the
nearest 0.01 m/s would ensure that the prescribed driving cycle does
not change with respect to driving schedules that are specified to the
nearest 0.1 mph. The regulations would include the appropriate mph (or
kph) speeds to allow for a ready understanding of speed values (see 40
CFR part 1037, Appendix I). This would, for example, allow for drivers
to continue to follow a mph-based speed trace. The 2 mph
tolerance on driving speeds could be converted to 1.0 m/s,
which corresponds to an effective speed tolerance of 2.2
mph. This may involve a tightening or loosening of the existing speed
tolerance, depending on whether manufacturers used the full degree of
flexibility allowed for a mph tolerance value that is specified without
a decimal place. Similarly, the Cruise cycles for heavy-duty vehicles
could be specified as 24.50.5 m/s (54.81.1 mph)
and 29.00.5 m/s (64.91.1 mph).
(4) Compliance Reports
(a) Early Model Year Data
    This information is the same as for tractors early model year data
in Section V.D(4)(a).
(b) Final Reports
    This information is the same as for tractors final reports in
Section V.D(4)(b).
(c) Additional Required Information
    Table V-7 below provides a summary of the types of requests,
required application submission dates and the EPA and NHTSA regulations
that apply.

                            Table V-7--Summary of Required Information for Compliance
----------------------------------------------------------------------------------------------------------------
                                                                                NHTSA
            Submission                    Applies to        Required submissions  EPA regulation    regulation
                                                                    date             reference       reference
----------------------------------------------------------------------------------------------------------------
Small business exemptions.........  Vehicle or engine      Before introducing               Sec.    Sec.   535.8
                                     manufacturers          any excluded vehicle        1037.150
                                     meeting the Small      into U.S. commerce.
                                     Business
                                     Administration (SBA)
                                     size criteria of a
                                     small business as
                                     described in 13 CFR
                                     121.201.
Incentives for early introduction.  The provisions apply   EPA must be notified             Sec.    Sec.   535.8
                                     with respect to        before the                  1037.150
                                     tractors and           manufacturer submits
                                     vocational vehicles    it applications for
                                     produced in model      certificates of
                                     years before 2014.     conformity.
Air condition leakage exemption     Vocational Vehicles    EPA must be notified             Sec.    Sec.   535.8
 for vocational vehicles.            excluded from Sec.     before the                  1037.150
                                     1037.115.              manufacturer submits
                                                            it applications for
                                                            certificates of
                                                            conformity.
Model year 2014 N2O standards.....  Manufacturers that     EPA must be notified             Sec.    Sec.   535.8
                                     choose to show         before the                  1037.150
                                     compliance with the    manufacturer submits
                                     MY 2014 N2O            it applications for
                                     standards requesting   certificates of
                                     to use an              conformity.
                                     engineering analysis.
Exemption for electric vehicles...  All electric vehicles  End of December prior            Sec.    Sec.   535.8
                                     are deemed to have     to model year.              1037.150
                                     zero exhaust
                                     emissions of CO2,
                                     CH4, and N2O.
Off-road exemption................  Manufacturers wanting  EPA must be notified             Sec.    Sec.   535.8
                                     to exclude             before the                  1037.150
                                     vocational vehicles    manufacturer submits
                                     from vehicle           it applications for
                                     standards.             certificates of
                                                            conformity.
Exemption from EOY reports........  Manufactures with      90-days after the                Sec.    Sec.   535.8
                                     surplus credits at     calendar year ends.         1037.730
                                     the end of the model
                                     year.
----------------------------------------------------------------------------------------------------------------

G. Penalties

(1) Overview
    In the NPRM, NHTSA proposed to assess civil penalties for non-
compliance with fuel consumption standards. NHTSA's authority under
EISA, as codified at 49 U.S.C. 32902(k), requires the agency to
determine appropriate measurement metrics, test procedures, standards,
and compliance and enforcement protocols for HD vehicles. NHTSA
interprets its authority to develop an enforcement program to include
the authority to determine and assess civil penalties for noncompliance
that would impose penalties based on the following discussions.
    In cases of noncompliance, the agency explained in the NPRM that it
would establish civil penalties based on consideration of the following
factors:
 Gravity of the violation.
 Size of the violator's business.
 Violator's history of compliance with applicable fuel
consumption standards.
 Actual fuel consumption performance related to the applicable
standard.
 Estimated cost to comply with the regulation and applicable
standard.
 Quantity of vehicles or engines not complying.
 Civil penalties paid under CAA section 205 (42 U.S.C. 7524)
for non-compliance for the same vehicles or engines.
    NHTSA proposed to consider these factors in determining civil
penalties in order to help ensure, given the agency's wide discretion,
that penalties would be fair and appropriate, and not duplicative of
EPA penalties. The NPRM expressly stated that neither agency intended
to impose duplicative civil penalties, and that both agencies would
give consideration to civil penalties imposed by the other in the case
of non-compliance with its own regulations. See NPRM at 74280.
    EMA, Volvo, the Truck Renting and Leasing Association (TRALA), and
Navistar nevertheless commented that a dual enforcement scheme with
separate NHTSA and EPA penalties could result in duplicative penalties,
as manufacturers could be assessed penalties twice for the same
violation.
    The possibility of more than one prosecution or enforcement action
arising from the same overall body of facts does not present a novel
issue. It commonly arises where there is overlapping jurisdiction, such
as where the federal government and a state government have
jurisdiction. The issue of multiple or sequential prosecutions may be
addressed as a matter of administrative policy and discretion.\319\
---------------------------------------------------------------------------

    \319\ A well-known example is the Department of Justice's petite
policy, an internal guide on whether to pursue federal prosecution
after a state prosecution. The petite policy is considered ``merely
a housekeeping provision,'' and prosecution remains entirely within
the Department's discretion. U.S. v. Barrett, 496 F.3d 1079, 1120
(10th Cir. 2007).
---------------------------------------------------------------------------

    Both NHTSA and EPA are charged with regulating medium-duty and
heavy-duty trucks; NHTSA regulates them under EISA and EPA regulates
them under the CAA. Both agencies also have compliance review and
enforcement responsibilities for their respective regulatory
requirements. The same set of underlying facts may result in a
violation of EISA and a violation of the CAA. The agencies recognize
the above concerns, and intend to address them through appropriate
consultation. The details of the consultation and coordination between
the agencies regarding enforcement will be set forth in a memorandum of
understanding to be developed by EPA and NHTSA.
    NHTSA believes that the above description adequately describes the
process by which civil penalties may be assessed by both agencies.
Therefore, for the final action, penalties for a violation of a fuel
consumption standard will be based on the gravity of the violation, the
size of the violator's business, the violator's history of compliance
with applicable fuel consumption standards, the actual fuel consumption
performance related to the applicable standard, the estimated cost to
comply with the regulation and applicable standard, and the quantity of
vehicles or engines not complying. The collaborative enforcement
process will ensure that the total penalties assessed will not be
duplicative or excessive.
    NHTSA would also like to clarify that the ``estimated cost to
comply with the regulation and applicable standard,'' will be used to
ensure that penalties for non-compliance will not be less than the cost
of compliance. It would be contrary to the purpose of the regulation

for the penalty scheme to incentivize noncompliance.
    The final civil penalty amount NHTSA could impose would not exceed
the limit that EPA is authorized to impose under the CAA. The potential
maximum civil penalty for a manufacturer would be calculated as follows
in Equation V-1:

Equation V-1: Aggregate Maximum Civil Penalty

Aggregate Maximum Civil Penalty for a Non-Compliant Regulatory Category
= (CAA Limit) x (production volume within the regulatory category)
    EPA has occasionally in the past conducted rulemakings to provide
for nonconformance penalties-- monetary penalties that allow a
manufacturer to sell engines or vehicles that do not meet an emissions
standard. Nonconformance penalties are authorized for heavy-duty
engines and vehicles under section 206(g) of the CAA. Three basic
criteria have been established by rulemaking for determining the