[Federal Register Volume 87, Number 176 (Tuesday, September 13, 2022)]
[Proposed Rules]
[Pages 56156-56202]
[FR Doc No: 2022-17134]

Vol. 87

Tuesday,

No. 176

September 13, 2022

Part II

Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Part 535

Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency Test
Procedures, and Other Technical Amendments; Proposed Rule

Federal Register / Vol. 87 , No. 176 / Tuesday, September 13, 2022 /
Proposed Rules

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 535

[NHTSA-2020-0079]
RIN 2127-AM28

Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency
Test Procedures, and Other Technical Amendments

AGENCY: National Highway Traffic Safety Administration, Department of
Transportation.

ACTION: Proposed rule.

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SUMMARY: The National Highway Traffic Safety Administration (NHTSA) is
proposing minor technical amendments to the test procedures for heavy-
duty engines and vehicles to improve accuracy and reduce testing
burden. These amendments affect the certification procedures for fuel
efficiency standards and related requirements. These proposed
amendments increase compliance flexibility, harmonize with other
requirements, add clarity, correct errors, and streamline the
regulations. Given the nature of the proposed changes, NHTSA does not
expect either significant environmental impacts or significant economic
impacts for any sector.

DATES: Comments: Comments are requested on or before November 14, 2022.

ADDRESSES: You may send comments, identified by Docket No. NHTSA-2020-
0079 by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov.
Follow the instructions for sending comments.
     Fax: NHTSA:<PHONE_NUMBER>.
     Mail:
    [cir] Docket Management Facility, M-30, U.S. Department of
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery:
    [cir] West Building, Ground Floor, Rm. W12-140, 1200 New Jersey
Avenue SE, Washington, DC 20590, between 9 a.m. and 4 p.m. Eastern
Time, Monday through Friday, except Federal holidays.
    Instructions: All submissions received must include the agency name
and docket number or Regulatory Information Number (RIN) for this
rulemaking. All comments received will be posted without change to
https://www.regulations.gov, including any personal information
provided.
    Docket: For access to the dockets to read background documents or
comments received, go to https://www.regulations.gov, and/or: Docket
Management Facility, M-30, U.S. Department of Transportation, West
Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590. The Docket Management NHTSA: Docket Management
Facility, M-30, U.S. Department of Transportation (DOT), West Building,
Ground Floor, Rm. W12-140, 1200 New Jersey Ave. SE, Washington, DC
20590. The DOT Docket Management Facility is open between 9 a.m. and 5
p.m. Eastern Time, Monday through Friday, except Federal holidays.
However, due to current COVID-19 restrictions, access to the office is
limited. Please call ahead if you plan to drop off or pick up a
document to ensure someone is available to assist them. The Docket
Management Facility can be reached at<PHONE_NUMBER> or<PHONE_NUMBER>
to arrange a drop off/pick up.

FOR FURTHER INFORMATION CONTACT: Gregory Powell, Office of Rulemaking,
Fuel Economy Division, National Highway Traffic Safety Administration,
1200 New Jersey Avenue SE, Washington, DC 20590; telephone number:
(202) 493-0515.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
    A. Does this action apply to me?
    B. What action is the Agency taking?
    C. What are the incremental costs and benefits of this action?
II. Medium and Heavy-Duty Fuel Efficiency Program Technical
Amendments
    A. Overview
    B. Greenhouse Gas Emission Model Supplemental Notice of Proposed
Rulemaking
    C. 49 CFR 535.3 Applicability
    D. 49 CFR 535.4 Definitions
    E. 49 CFR 535.5 Standards
    F. 49 CFR 535.6 Measurement and Calculation Procedures
    G. 49 CFR 535.7 Averaging, Banking, and Trading (ABT) Credit
Program
    H. 49 CFR 535.8 Reporting and Recordkeeping Requirements
    I. 49 CFR 535.9 Enforcement Approach
    J. 49 CFR 535.10 How do manufacturers comply with fuel
consumption standards?
III. Statutory Authority and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use
    I. National Technology Transfer and Advancement Act (NTTAA)
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
IV. Regulatory Text

I. General Information

A. Does this action apply to me?

    This action would affect companies that manufacture, sell, or
import into the United States new heavy-duty engines and new Class 2b
through 8 trucks, including combination tractors, all types of buses,
vocational vehicles including municipal, commercial, recreational
vehicles, and \3/4\-ton and 1-ton pickup trucks and vans. The heavy-
duty category incorporates all motor vehicles with a gross vehicle
weight rating of 8,500 lbs. or greater, and the engines that power
them, except for medium-duty passenger vehicles already covered by the
corporate average fuel economy standards and greenhouse gas standards
issued for light-duty vehicles.\1\
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    \1\ https://www.ecfr.gov/cgi-bin/text-idx?SID=7031ab132d93d2ab3729f7c3b8e412f0&mc=true&node=pt49.6.535&rgn=div5.
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    Regulated categories and entities include the following:

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                                                         Examples of
           Category               NAICS codes \A\        potentially
                                                      regulated entities
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Industry.....................  333618, 336111,       Motor vehicle
                                336112, 336120,       manufacturers and
                                336211, 336212,       engine
                                336611, 336911,       manufacturers.
                                336999.
Industry.....................  811111, 811112,       Commercial
                                811198, 423110.       importers of
                                                      vehicles and
                                                      vehicle
                                                      components.
Industry.....................  335312, 811198......  Alternative fuel
                                                      vehicle
                                                      converters.
Industry.....................  326199, 332431......  Portable fuel
                                                      container
                                                      manufacturers.
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\A\ North American Industry Classification System (NAICS).

    This list is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. If you have questions regarding the applicability of this
action to a particular entity, consult the person listed in the FOR
FURTHER INFORMATION CONTACT section.

B. What action is the Agency taking?

    This action proposes to amend the regulations that implement our
fuel efficiency standards for engines and vehicles. The proposed
amendments are technical in nature and include corrections and
clarifications to a variety of existing regulatory provisions to
improve consistency with related EPA standards and with NHTSA's
original intent for those provisions. In other words, this proposal
comprises a variety of small changes for multiple types of engines and
vehicles.
    These amendments parallel similar ones in a rulemaking conducted by
the EPA under RIN 2060-AU62. The proposed technical amendments are
intended to maintain the alignment of EPA's Medium and Heavy-Duty
Vehicle Greenhouse Gas Emissions and NHTSA's Fuel Efficiency Standards.
The technical amendments to NHTSA regulations contained in this
proposal are both necessary and completely align with the technical
amendments finalized by EPA under the parallel rulemaking referenced in
this paragraph.
    The majority of the amendments being proposed would modify existing
test procedures for heavy-duty highway engines and vehicles. These test
procedure changes would improve accuracy, and in some cases, reduce
test burden.
    Other heavy-duty highway amendments would update NHTSA regulations
to enhance implementation of existing fuel efficiency standards. For
example, some changes would reduce the likelihood that manufacturers
would need to conduct unique certification testing for compliance with
NHTSA, Canadian, and Californian standards. Some amendments would make
it easier for manufacturers to more fully account for the fuel
efficiency benefits of advanced fuel efficiency improving technology,
which could provide them the opportunity to generate additional fuel
consumption improvements for compliance. These amendments are described
in Section II.
    Additionally, as a matter of housekeeping, NHTSA is proposing to
remove portions of its regulations that were vacated by the United
States Court of Appeals for the District of Columbia Circuit. In
November 2021, that Court ``vacate[d] all portions of the [2016 joint
NHTSA and EPA] rule that apply to trailers.'' Truck Trailer Mfrs.
Ass'n, Inc. v. EPA, 17 F.4th 1198, 1200 (D.C. Cir. 2021). The
underlying statute authorizes NHTSA to examine the fuel efficiency of
and prescribe fuel economy standards for ``commercial medium-duty [and/
or] heavy-duty on-highway vehicles.'' 49 U.S.C. 32902(b)(1)(C); 49
U.S.C. 32902(k)(2). The Court reasoned that trailers do not qualify as
``vehicles'' when that term is used in the fuel economy context because
trailers are motorless and use no fuel. Truck Trailer Mfrs. Ass'n,
Inc., 17 F.4th at 1200, 1204-08. Accordingly, the Court held that NHTSA
does not have the authority to regulate the fuel economy of trailers.
Id. at 1208.\2\ NHTSA is therefore proposing to remove the vacated
trailer provisions from its regulations
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    \2\ For similar reasons, the Court also held that the statute
authorizing EPA to regulate the emissions of ``motor vehicles'' does
not encompass trailers. Id. at 1200-03. The Court affirmed, however,
that both agencies still ``can regulate tractors based on the
trailers they pull.'' Id. at 1208. Moreover, NHTSA is still
authorized to regulate trailers in other contexts, such as under 49
U.S.C. Chapter 301. See 49 U.S.C. 30102(a)(7) (defining ``motor
vehicle'' to include ``a vehicle . . . drawn by mechanical power'');
Truck Trailer Mfrs. Ass'n, Inc., 17 F.4th at 1207 (``A trailer is
`drawn by mechanical power.' '').
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C. What are the incremental costs and benefits of this action?

    This action would be limited in scope and is not intended to
include amendments that would have significant economic or
environmental impacts. NHTSA has not drafted a Regulatory Impact
Analysis.

II. Medium and Heavy-Duty Fuel Efficiency Program Technical Amendments

A. Overview

    In September 2011, NHTSA and EPA finalized Phase 1 of the
Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and
Heavy-Duty Engines and Vehicles. The Phase 1 program covered new
commercial heavy-duty vehicles and work trucks manufactured in model
years 2014 to 2018 and beyond, with unique standards for combination
tractors, heavy-duty pickup trucks and vans, and vocational vehicles,
as well as separate standards for engines in tractors and vocational
vehicles. NHTSA and EPA finalized Phase 2 of the standards in October
2016. Besides standards being more stringent, the Phase 2 program also
incorporated enhanced test procedures that (among other things) allow
individual drivetrain and powertrain performance to be reflected in the
vehicle certification process; and included an expanded and improved
compliance simulation model.
    Since the promulgation of the Phase 2 regulations, manufacturers
have been revising their internal test procedures for compliance with
the new requirements that begin in model year 2021. In doing so, they
have identified to the agencies several areas in which the test
procedure regulations could be improved (in terms of overall accuracy,
repeatability and clarity) without changing the effective stringency of
the standards.
    In its May 12, 2020 NPRM, EPA proposed numerous changes to the test
procedure regulations to address manufacturers' concerns and to address
other issues it had identified. EPA sought comment on those changes and
issued a final rule on December 28, 2020 responding to the comments and
adjusting the regulatory changes as appropriate. NHTSA has carefully
reviewed all technical amendments in the EPA proposal, public comments
to the proposal, and the technical amendments that EPA finalized, and
is proposing to make technical amendments that parallel the technical
amendments that EPA finalized. NHTSA's proposed regulatory changes

described below consist primarily of references and definitions
contained in NHTSA regulations which were impacted by the technical
amendments finalized by the EPA. This proposal also includes various
minor editorial changes to NHTSA regulations that simply correct
typographical/formatting errors or revise NHTSA's regulatory text to
improve clarity or to update references to EPA regulations that have
changed as a result of the EPA technical amendments.

B. Greenhouse Gas Emission Model Supplemental Notice of Proposed
Rulemaking

    In conjunction with its final rule issued on December 28, 2020, EPA
issued a supplemental notice of proposed rulemaking (SNPRM) proposing
further revisions to the Greenhouse Gas Emissions Model (GEM). In the
supplemental notice of proposed rulemaking, EPA proposed to revise GEM
after consideration of comments solicited and received on the Technical
Amendments proposed rule. The details of these changes to the GEM and
other considerations are provided on EPA's website.\3\
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    \3\ ``Greenhouse Gas Emissions Model (GEM) for Medium- and
Heavy-Duty Vehicle Compliance.'' (n.d.). https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty. Accessed May 18, 2022.
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C. 49 CFR 535.1 Scope

    NHTSA is proposing to amend the scope provision of 49 CFR part 535
to remove the reference to trailers, consistent with the 2021 D.C.
Circuit decision as discussed above.

D. 49 CFR 535.3 Applicability

1. 535.3 (a) Enforcement Action Related to Compliance With NHTSA
Standards
    NHTSA is proposing clarifications to its MDHD fuel efficiency
program's applicability and compliance. More specifically, NHTSA is
adding the clarification that manufacturers found not to comply with
NHTSA's standards or regulations which apply to the construction of new
and incomplete vehicles in 49 CFR parts 566 through 568 due to
incorrect or fraudulent information will be subject to enforcement in
accordance with Chapter 301 of Title 49 and deemed as not complying
with Part 535. For example, if a manufacturer is unregistered with
NHTSA as a manufacturer, as required by Part 566, or fails to affix an
accurate certification label to a complete or incomplete vehicle, then
the manufacturer concurrently violates both NHTSA's safety and fuel
efficiency regulations. If the manufacturer is unable to correct its
noncompliance(s), the manufacturer fails to comply with NHTSA's fuel
efficiency program and is unable to earn fuel efficiency credits or
must forfeit its credits, if already issued by NHTSA.
2. 535.3(d)(5) Exclusion of Heavy-Duty Trailers
    NHTSA is proposing to delete 535.3(d)(5) consistent with the 2021
D.C. Circuit decision, discussed above.
3. 535.3(e)(1)(i) Vocational Vehicle Tire Speed Rating Exemption
    NHTSA is proposing to update this section with a new applicability
provision for vocational vehicles, to reflect the rulemaking intention
and to be consistent with EPA regulations. The added provision allows
for vocational vehicles with a date of manufacture before January 1,
2021 to automatically qualify for an exemption under 40 CFR 1037.631 if
the tires installed on the vehicle have a maximum speed rating at or
below 55 miles per hour.
4. 535.3(e)(1)(ii) Request for Exemption
    NHTSA is proposing to add a second exemption clause to this section
where vehicle manufacturers may request exemption under the EPA defined
provisions found in 40 CFR 1037.631 and based on other criteria that
are equivalent to those specified in 40 CFR 1037.631(a).
5. 535.3(e)(2)(ii) Early Certification for Small Manufacturers
    Vehicle manufacturers that qualify as small businesses are exempt
from the Phase 1 standards, but must meet the Phase 2 standards
beginning January 1, 2022.\4\ However, some vehicle families have been
certified voluntarily to Phase 1 standards by small manufacturers. In
an effort to encourage more voluntary early certification to Phase 1
standards, EPA finalized a new interim provision in 40 CFR
1037.150(y)(4) for small manufacturers that certify their entire U.S.-
directed production volume to the Phase 1 standards for calendar year
2021 (see 85 FR at 28150). These small manufacturers would be allowed
to certify to the Phase 1 standards for model year 2022, instead of the
otherwise applicable Phase 2 standards. The agencies believe that early
compliance with the Phase 1 standards should more than offset any
reduction in benefits that would otherwise be achieved from meeting
Phase 2 standards starting January 1, 2022.\5\
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    \4\ In December 2020, EPA proposed further revisions to the
Phase 2 GEM Simulation Model in the December 2020 Notice of Proposed
Rulemaking (NRPM) for technical amendments to the GHG Emissions
Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty
VehicleS. EPA's GEM model is released and can be found https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty which incorporates the
revisions being considered.'' (last accessed: May 11, 2022)
    \5\ EPA stated that it believed that the magnitude of any impact
on air quality would be small because of the low production volumes
from these small business manufacturers.
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    The finalized provision also allows the Phase 1 compliance credits
that small manufacturers generate from model year 2018 through 2022
vocational vehicles to be used through model year 2027. Under the
existing regulations, all manufacturers that generate vehicle credits
under the Phase 1 program can use these credits for compliance in the
Phase 2 averaging, banking, and trading program, but these credits are
only subject to a five-year credit life. As EPA stated in its final
rule, the agencies believe that the limit on credit life can be
problematic for small manufacturers with limited product lines which
allows them less flexibility in averaging, and the longer credit life
will provide them additional flexibility to ensure all their products
are fully compliant by the time the Phase 2 standards are fully phased
in for model year 2027.
    EPA received no adverse comment to either proposal for small
manufacturers in Sec.  1037.150(y)(4) and, therefore, finalized the
provisions. NHTSA is proposing to implement parallel changes by
updating Sec.  535.5(e)(2)(ii) with the same provisions which can be
found at Sec.  535.5(e)(2)(ii)(A) and Sec.  535.5(e)(2)(ii)(B),
respectively. These changes would also maintain program alignment
across both agencies.
6. 535.3(e)(3)--Transitional Allowance for Trailers
    NHTSA is proposing to delete 535.3(e)(3) consistent with the 2021
D.C. Circuit decision, discussed above.
7. 535.3(j) Potential Enforcement Actions for Incomplete, Incorrect or
Fraudulent Information
    NHTSA is proposing to add a new section to the program
applicability regulations. This new section provides clarifications and
potential outcomes under the NHTSA fuel efficiency program, if EPA
denies, suspends or revokes, a manufacturer's certificate of conformity
in accordance with 40 CFR 1036.255 or 1037.225, due to incomplete,
incorrect or fraudulent information.

E. 49 CFR Part 535.4 Definitions

    NHTSA is proposing adding and modifying several definitions to
clarify the meaning of certain terms. Almost all of these definitions
reference EPA regulatory definitions to ensure alignment of the NHTSA
and EPA programs.
1. Adjustable Parameter
    NHTSA is proposing to add the definition for adjustable parameter
as having the meaning given in 40 CFR 1037.801.
2. Alternative Fuel Conversion
    NHTSA is proposing to add the definition for alternative fuel
conversion as having the meaning given in 40 CFR 85.502.
3. Averaging Sets
    NHTSA is proposing to delete ``long trailer'' and ``short trailer''
in reference to averaging sets definition in HD program, consistent
with the 2021 D.C. Circuit decision.
4. Certificate of Conformity
    After receiving no adverse comments, EPA finalized clarifying
statements related to the information submitted in an application for a
certificate of conformity. These clarifying statements are related to
determining the date of application submission and the submission date
for any potential changes to applications that are deemed incomplete or
amended. NHTSA is proposing to update its Certificate of Conformity
definition in Part 535 to include the same language finalized by EPA
because the clarifications are also applicable to NHTSA's fuel
efficiency program. These changes would also maintain program alignment
across the agencies.
5. Hybrid Engine, Hybrid Powertrain, and Hybrid Vehicle
    NHTSA is proposing to revise its definition of hybrid engine or
hybrid powertrain in 49 CFR part 535.4 to reference directly the EPA
definition for these powertrain types found in 1037.801. EPA changed
its definitions for ``hybrid engine or powertrain'' and ``hybrid
vehicle'' to be consistent with the revised hybrid powertrain test
procedures it recently finalized in part 1036 subpart F, and the
definitions of ``hybrid powertrain'' and ``mild hybrid'' added to 40
CFR part 1036. NHTSA is proposing corresponding revisions to the Part
535 definitions that add examples of systems that qualify as hybrid
engines or powertrains, specifically systems that recover kinetic
energy and use it to power an electric heater in the aftertreatment.
6. Emission Data Engine
    NHTSA is proposing to add the definition for emission data engine
as having the meaning given in 40 CFR 1036.801.
7. Engine Configuration
    NHTSA is proposing to add the definition for engine configuration
as having the meaning given in 40 CFR 1036.801.
8. Flatbed Trailer
    NHTSA is proposing to delete the definition of flatbed trailer,
consistent with the 2021 D.C. Circuit decision.
9. Flexible Fuel
    NHTSA is proposing to add the definition for flexible fuel as
having the meaning given in 40 CFR 1036.801.
10. Fuel Type
    NHTSA is proposing to add the definition for fuel type as having
the meaning given in 40 CFR 1036.801.
11. Gear Ratio
    NHTSA is proposing to add the definition for gear ratio as having
the meaning given in 40 CFR 1036.801.
12. Greenhouse Gas
    NHTSA is proposing to add the definition for greenhouse gas as
having the meaning given in 40 CFR 1036.801.
13. Good Engineering Judgment
    NHTSA is proposing to add the definition for good engineering
judgement as having the meaning given in 40 CFR 1068.30.
14. Heavy-Duty Engine
    NHTSA is proposing to add the definition for heavy-duty engine as
having the meaning given in 40 CFR 1036.801 and 49 CFR part 523.
15. Hybrid
    NHTSA is proposing to add the definition for hybrid as having the
meaning given in 40 CFR 1036.801.
16. Identification Number
    NHTSA is proposing to add the definition for identification number
as having the meaning given in 40 CFR 1037.801.
17. Manufacturer
    NHTSA is proposing to add the definition for manufacturer as having
the meaning given in 40 CFR 1037.801.
18. Model Year
    NHTSA is proposing revisions to the definition for model year as it
pertains to vehicles and engine installations. NHTSA is also proposing
to delete references to trailers in this definition, consistent with
the 2021 D.C. Circuit decision.
19. Motor Vehicle
    NHTSA is proposing to add the definition for motor vehicle as
having the meaning given in 49 U.S.C. 32901.
20. Multi-Purpose
    NHTSA is proposing to add the definition for multi-purpose as
having the meaning given in 40 CFR 1037.801.
21. Neutral-Idle
    NHTSA is proposing to add the definition for neutral idle as having
the meaning given in 40 CFR 1037.801.
22. New Vehicles
    NHTSA is proposing to add the definition for new vehicles as having
the meaning given to ``new motor vehicle'' given in 40 CFR 1037.801.
23. Percent
    NHTSA is proposing to add the definition for percent as having the
meaning given in 40 CFR 1037.801.
24. Placed Into Service
    NHTSA is proposing to add the definition for placed into service as
having the meaning given in 40 CFR 1037.801.
25. Phase 2
    NHTSA is proposing to delete reference to fuel efficiency and
greenhouse gas emissions standards for trailer regulations, consistent
with the 2021 D.C. Circuit decision.
26. Regulatory Subcategory
    NHTSA is proposing to delete the section (4) reference to trailer
subcategory, consistent with the 2021 D.C. Circuit decision.
27. Relating
    NHTSA is proposing to add the definition for relating as having the
meaning given in 40 CFR 1037.801.
28. Round
    NHTSA is proposing to add the definition for round as having the
meaning given in 40 CFR1065.1001.
29. Standard Payload
    NHTSA is proposing to remove the definition of standard payload for
trailers, consistent with the 2021 D.C. Circuit decision.
30. Standard Tractor
    NHTSA is proposing to correct the definition for standard tractor
as having

the meaning given in 40 CFR 1037.801 versus the currently defined 40
CFR 1037.501.
31. Standard Trailer
    NHTSA is proposing to correct the definition for standard trailer
as having the meaning given in 40 CFR 1037.801 versus the currently
defined 40 CFR 1037.501.
32. Suspend
    NHTSA is proposing to add the definition for suspend as having the
meaning given in 40 CFR 1037.801.
33. Vehicle Service Class
    NHTSA is proposing to revise the vehicle service class definition
found in 49 CFR part 535.4 to directly reference EPA regulation 40 CFR
1037.140. NHTSA is proposing this revision to avoid redundancy across
the agencies and align directly with EPA revisions finalized in their
recent technical amendments rulemaking.
    The recent EPA technical amendments clarify that the classification
for tractors, where provisions are the same as vocational vehicles, are
applicable to both hybrid and non-hybrid vehicles. The amendments also
clarify that Class 8 hybrid and electric vehicles are Heavy HDVs while
all other vehicles are classified by GVWR classes.
    EPA explained in its final rule that prior to these revisions,
manufacturers had expressed concern that the Phase 2 regulations were
not specific enough regarding how to classify hybrid vocational
vehicles, because vocational vehicles are generally classified by the
class of the engines (as opposed to tractors, which are classified
based on GVW), which was not applicable to electrically driven vehicles
that have no engine.
34. Void
    NHTSA is proposing to add the definition for void as having the
meaning given in 40 CFR 1037.801.

F. 49 CFR Part 535.5 Standards

1. 49 CFR Part 535.5(a)
    NHTSA is proposing to add clarification to the regulatory standards
relating to heavy-duty pickup trucks and vans. More specifically, the
agency is proposing adding language that ensures manufacturer options
for EPA and NHTSA vehicle standards are aligned. Please refer to the
proposed regulatory text for additional details.
2. 49 CFR Part 535.5(b)
    NHTSA is proposing to add clarification to the regulatory standards
relating to heavy-duty vocational vehicles. More specifically, the
agency is proposing adding language that ensures manufacturer options
for EPA and NHTSA vehicle standards are aligned. Please refer to the
proposed regulatory text under this section for additional details.
3. 49 CFR Part 535.5(b)(1)
    NHTSA is proposing deletion of the mandatory requirements for all
heavy-duty vocational vehicles to be equipped tire pressure monitoring
systems. The proposed revision, however, does not include removal of
this mandatory requirement for motorhomes, as specified under 49 CFR
part 535.5 (b)(6)(vi) and 49 CFR 571.138.
4. 49 CFR Part 535.5(b)(4)
    NHTSA is proposing to correct the Vocational HHD Vehicle Regional
compression ignition (CI) standards. The current published standard for
this vehicle class is incorrect, and does not align with EPA GHG
standards for this vehicle type. The incorrect values resulted from an
incorrect calculation during the Phase 2 rulemaking which intended to
maintain alignment of the NHTSA and EPA standards. The proposed
corrected value for this regulatory class is 20.1375 gallons per 1000-
ton miles vs. the currently published standard of 20.2358.
5. 49 CFR Part 535.5(c)
    NHTSA is proposing to add clarification to the regulatory standards
relating to truck tractors. More specifically, the agency is proposing
adding language that ensures manufacturer options for EPA and NHTSA
vehicle standards are aligned across both agencies. Please refer to the
proposed regulatory text for additional details.
6. 49 CFR Part 535.5(c)(5)
    NHTSA is proposing to revise its Alternate Fuel Consumption
Standards for Tractors above 120,000 GCWR for 2021 model year and
later. The revised standards are directly aligned with the revised GHG
standards for this class of vehicles proposed and finalized by EPA as
part of its technical amendments rulemaking.\6\ The revised standards
provide additional clarity on this vehicle class along with fuel
efficiency standards that increase in three increments, model years
2021-2023, model years 2024-2026, model years 2026 and later.
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    \6\ In December 2020, EPA proposed further revisions to the
Phase 2 GEM Simulation Model in the December 2020 Notice of Proposed
Rulemaking (NRPM) for technical amendments to the GHG Emissions
Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty
Vehicles and is soliciting comments on these revisions. S. The
latest EPA's GEM model is released and can be found https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty which incorporates the
revisions being considered.'' (last accessed: May 11, 2022)
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    As described in EPA's final rulemaking action, the agencies
originally defined these alternate fuel consumption and greenhouse-gas
standards during the Phase 2 rulemaking, to enable Environment and
Climate Change Canada (ECCC) to fully harmonize with the U.S.'s HD
Phase 2 standards.
    In the interim, ECCC has since adopted final standards for these
120,000 to 140,000 pound GCWR tractors, which differ from the optional
standards finalized in Phase 2.\7\ Since the purpose of these standards
was to facilitate certification of vehicles intended for Canada, EPA
proposed optional standards in 40 CFR 1037.670 that would be the same
as the final ECCC standards, and did not receive any adverse comments
regarding that proposal. NHTSA is proposing to adopt these alternative
standards, in gallons per 1,000 ton-miles units, for 120,000 to
140,000-pound GCWR tractors that are equivalent to the EPA and ECCC
standards. This would maintain harmonization across the programs for
all three agencies.
---------------------------------------------------------------------------

    \7\ Regulations Amending the Heavy-duty Vehicle and Engine
Greenhouse Gas Emission Regulations and Other Regulations Made Under
the Canadian Environmental Protection Act, 1999: SOR/2018-98, Canada
Gazette, Part II, Volume 152, Number 11, May 16, 2018.
---------------------------------------------------------------------------

7. 49 CFR Part 535.5(d)
    NHTSA is proposing to add clarifications in 49 CFR part 535.5(d)
and 535.6(d) to expand its regulatory provision to optionally
accommodate powertrain families and subfamilies added by EPA in 40 CFR
1036.108(a) and 1036.230(d) and (f). The EPA provisions allow
manufacturers to apply CO2 standards to powertrain families
and subfamilies. They also allow manufacturers to optionally certify
powertrains using the engine testing provisions in 40 CFR 1036 instead
of 40 CFR 1037. Manufacturers may choose to include electric powertrain
and hybrid electric powertrain emissions in their engine families or
subfamilies under part 1036 instead of (or in addition to) the
otherwise applicable engine fuel maps. Doing so would provide the same
compliance options for manufacturers under the EPA and NHTSA programs.

8. 49 CFR Part 535.5(d)(3)
    NHTSA is proposing to correct the Heavy-Duty Engine Fuel
Consumption Standards for Phase 1 MHD and HHD compression ignition (CI)
tractor engines. The current published standards for these engine
classes are incorrect, and do not align with EPA GHG standards for
these engine types. The incorrect values resulted from an incorrect
calculation during the Phase 2 rulemaking which intended to maintain
alignment of the NHTSA and EPA standards. The proposed correct values
for these regulatory classes are 4.7839 gallons per 100 hp-hr for MHD
CI tractor engines and 4.5187 gallons per 100 hp-hr for HHD CI tractor
engines.
9. 49 CFR Part 535.5(d)(11)
    NHTSA is proposing to correct the Alternate transition option for
Phase 2 engine standards (A) and (C). The current published standards
for these engine standards are incorrect, and do not align with current
EPA GHG standards for these engine types. The incorrect values resulted
from an incorrect calculation during the Phase 2 rulemaking which
intended to maintain alignment for the NHTSA and EPA standards. The
proposed corrected values for these regulatory classes are 5.3241
gallons per 100 hp-hr for MHD vocational vehicle engines and 5.0098
gallons per 100 hp-hr for HHD vocational engines.
10. 49 CFR Part 535.5(e)
    NHTSA is proposing to delete 535.3(e), Heavy Duty Trailer,
consistent with the 2021 D.C. Circuit decision, discussed above.

G. 49 CFR Part 535.6 Measurement and Calculation Procedures

1. 49 CFR Part 535.6(b)(1)
    NHTSA is proposing to add a reference to EPA's finalized regulation
40 CFR 1037.150 to 49 CFR part 535.6(b)(1). This added reference would
provide clear guidance that would be used to determine the proper
vehicle and vehicle family to select when determining a manufacturer's
regulatory subcategories for vocational vehicles and tractors. The
addition would also maintain program alignment across the agencies.
2. 49 CFR Part 535.6(b)(4)(ii)
    NHTSA is proposing to add a reference to EPA's finalized regulation
40 CFR 1037.525 to 49 CFR part 535.6(b)(4)(ii). This added reference
would clarify how to determine a high-roof tractor's aerodynamic
performance. EPA finalized this revision to more clearly relate the
drag areas to the defined effective yaw variable, as recommended by EMA
as a comment to the EPA proposal.\8\ NHTSA is proposing to adopt this
same measurement schema to keep programs aligned across the agencies.
---------------------------------------------------------------------------

    \8\ The variables
CdAeffective-yaw-coastdown and
CdAeffective-yaw-alt are now
CdAcoastdown([psi]eff) and
CdAalt([psi]eff), respectively.
---------------------------------------------------------------------------

3. 49 CFR Part 535.6(b)(5)(i)
    NHTSA is proposing to revise 49 CFR part 535.6(b)(5)(i) to change
the reference to an EPA regulation from 40 CFR 1036.510 to 1036.503.
This revision would align the NHTSA regulations with the revised and
finalized EPA regulations. This change would keep the programs of both
agencies aligned.
4. 49 CFR Part 535.6(b)(5)(v)(E)(3)
    NHTSA is proposing to add a new requirement in 49 CFR part
535.6(b)(5)(v)(E)(3) that allows manufacturers to characterize torque
converters to allow a manufacturer to determine their own torque
converter capacity factor instead of using the default value provided
in GEM. This change aligns with EPA provisions in 40 CFR 1037.570 and
maintains program alignment across both agencies.
5. 49 CFR Part 535.6(b)(5)(v)(E)(4)
    NHTSA is proposing to add a new requirement in 49 CFR part
535.6(b)(5)(v)(E)(4) to allow vocational vehicles to input a value for
neutral coasting in GEM as a compliance option for its fuel consumption
program. This revision would align the NHTSA regulations with the EPA
regulations in 40 CFR 1037.52 and keep both agencies aligned for
program compliance.
6. 49 CFR Part 535.6(d)
    Like 49 CFR part 535.5(d), NHTSA is proposing to add clarifications
in NHTSA 535.6(d) to expand its regulatory provision to optionally
accommodate powertrain families and subfamilies added by EPA in 40 CFR
1036.108(a) and 1036.230(d) and (f). The EPA provisions allow
manufacturers to apply CO2 standards to powertrain families
and subfamilies. They also allow manufacturers to optionally certify
powertrains using the engine testing provisions in 40 CFR 1036 instead
of 40 CFR 1037. Manufacturers may choose to include electric powertrain
and hybrid electric powertrain emissions in their engine families or
subfamilies under part 1036 instead of (or in addition to) the
otherwise applicable engine fuel maps. Doing so would provide the same
compliance options for manufacturers under the EPA and NHTSA programs.
7. 49 CFR Part 535.6(d)(1)
    NHTSA is proposing a consolidation of references to EPA regulation
40 CFR 1036.501 for engines in heavy-duty truck tractors and vocational
vehicles that make up each of the manufacturer's regulatory
subcategories.
8. 49 CFR Part 535.6(d)(2)
    Like 49 CFR part 535.6(d), NHTSA is proposing to add clarifications
to 535.6(d)(2) that align with the EPA regulation 40 CFR 1036.230(f)
and to expand this regulatory provision to accommodate powertrains
other than engines and to also include sub-families.
9. 49 CFR Part 535.6(d)(3)
    NHTSA is proposing to add a new section to 49 CFR part 535.6(d) to
address medium and heavy heavy-duty engines. This new subsection (3)
mirrors and references the recently finalized EPA technical amendment
for 40 CFR 1036.501 addressing the same regulatory items. Subsequently,
existing sections 49 CFR part 535.6(d)(3) and 49 CFR part 535.6(d)(4)
would be incremented by one as a result of inserting this new section,
resulting in the existing 49 CFR part 535.6(d)(3) becoming 49 CFR part
535.6(d)(4), and the existing 49 CFR part 535.6(d)(4) becoming 49 CFR
part 535.6(d)(5).
10. 49 CFR Part 535.6(d)(3)(ii)
    NHTSA is proposing to add clarifications to 49 CFR part
535.6(d)(3)(ii) that expand this regulatory provision to accommodate
powertrains other than engines and to also include sub-families.
11. 49 CFR Part 535.6(e)
    NHTSA is proposing to delete 49 CFR part 535.6(e) reference to
heavy duty trailer, consistent with the 2021 D.C. Circuit decision.

H. 49 CFR 535.7 Averaging, Banking, and Trading (ABT) Credit Program

1. 49 CFR Part 535.7(a)
    NHTSA is proposing to delete reference to trailer manufacturers,
consistent with the 2021 D.C. Circuit decision.
2. 49 CFR Part 535.7(a)(2)(v)
    NHTSA is proposing to delete reference to application of using bank
or trade credit to trailer, consistent with the 2021 D.C. Circuit
decision.

3. 49 CFR Part 535.7(a)(3)(v)
    NHTSA is proposing to delete reference to trailer manufacturers
generating credits, consistent with the 2021 D.C. Circuit decision.
4. 49 CFR part 535.7(a)(4)
    NHTSA is clarifying its requirements for trading fuel consumption
credits. Tractor, vocational vehicle and engine manufacturers may trade
credits generated for vehicle or engine families or subfamilies while
manufacturers of heavy-duty pickup trucks and vans certified as
complete vehicles may trade credits generated for averaging sets. NHTSA
is also proposing to delete reference to trading credits earned for
compliance with trailer regulations, consistent with the 2021 D.C.
Circuit decision.
5. 49 CFR Part 535.7(a)(4)(v)
    NHTSA is proposing to delete reference to trailer manufacturers
generating credits starting in model year 2027 may not bank or trade
credits, consistent with the 2021 D.C. Circuit decision.
6. 49 CFR Part 535.7(a)(8)
    The agency is proposing additions to the credit calculation
provisions and to the calculations used for vocational vehicles
transitioning to Phase 2 standards. More specifically, NHTSA is
proposing to mirror the crediting provisions finalized by EPA as part
of their technical amendments rulemaking. These added provisions
include extending credit life, allowing off-cycle credits, allowing
credit values for automatic tire inflation systems, and allowing
automatic engine shutdown systems.
7. 49 CFR Part 535.7(a)(9)(iv)(B)
    NHTSA is proposing to provide clarifications regarding production
limits for drayage tractors under the custom chassis allowance, and how
it relates to corporate relationships regarding averaging, banking and
trading of credits.
8. 49 CFR Part 535.7(a)(11)
    NHTSA is proposing regulatory provisions that prevent the
calculation of any Phase 1 fuel consumption credits more than once for
compliance unless the regulations explicitly allow it.
9. 49 CFR Part 535.7(b)(1)
    NHTSA is proposing to amend the Total MY Fleet FCC equation because
the current CFR shows an incorrect equation.
10. 49 CFR Part 535.7(c)(1)
    NHTSA is proposing to amend the Vehicle Family FCC equation because
the current CFR shows an incorrect equation.
11. 49 CFR Part 535.7(d)(1)
    NHTSA is proposing to amend the Engine Family FCC equation because
the current CFR shows an incorrect equation.
12. 49 CFR Part 535.7(d)(7)(ii)
    NHTSA is proposing to the remove the usage restrictions associated
with model year 2021 and earlier vocational engine credits.
Manufacturers may use Phase 1 credits in the Phase 2 program using an
adjustment factor to prorate credits to compensate for changes in the
technologies and drive cycles used in developing the Phase 2 standards.
NHTSA is also correcting the adjustment factor values used for the
conversion to fuel consumption values in terms of gallons/100 hp-hr
versus the currently published grams of CO2 reference
values.
13. 49 CFR 535.7(e)
    NHTSA is proposing to delete 535.7(e), ABT Provision for Trailers,
consistent with the 2021 D.C. Circuit decision, discussed above.
14. 49 CFR 535.7(f)(2)(v)
    NHTSA is proposing to delete the provision formerly labeled as
535.7(f)(2)(v) reference to application of off-cycle provision to
trailers, consistent with the 2021 D.C. Circuit decision, discussed
above.

I. 49 CFR 535.8 Reporting and Recordkeeping Requirements

1. 49 CFR Part 535.8(a)(6)
    NHTSA is proposing to amend the address to 1200 New Jersey Avenue,
NVS-200, Office W45-306, SE, Washington, DC 20590, because the current
CFR shows an incorrect address.
2. 49 CFR Part 535.8(b)(11)(i)(C)
    Like 49 CFR part 535.6(d), NHTSA is proposing to add clarifications
to 49 CFR part 535.8(b)(11)(i)(C) that expand this regulatory provision
to accommodate powertrains other than engines and to also include sub-
families.
3. 49 CFR Part 535.8(c)(13)(h)(i)
    NHTSA is proposing additions to this reporting requirement that
clarify potential enforcement actions associated with the submission of
information that is fraudulent or grossly negligent or otherwise
provided in bad faith.
4. 49 CFR Part 535.8(g)(12)
    NHTSA is proposing to delete reference to requirements for trailer
manufacturers, consistent with the 2021 D.C. Circuit decision,
discussed above.

J. 49 CFR 535.9 Enforcement Approach

1. 49 CFR Part 535.9(a)(1)(i)
    NHTSA is proposing additional language and clarifications that
NHTSA will perform confirmatory testing and collaborate with EPA
regarding any potential issues with testing results.
2. 49 CFR Part 535.9(a)(1)(v)
    NHTSA is proposing additional language and clarifications with
respect to any GEM inputs in a manufacturer's application for
certification or in the end of the year ABT final reports. The proposed
revisions include streamlining references to EPA regulations.

K. 49 CFR 535.10 How do manufacturers comply with fuel consumption
standards?

1. 49 CFR Part 535.10(a)(3)
    NHTSA is clarifying that EPA's compliance requirements 40 CFR
1037.601 and 40 CFR part 1068 apply similarly to NHTSA's fuel
consumption program, except for the warranty provisions in 40 CFR
1037.601(a)(5).
2. 49 CFR Part 535.10(a)(6)
    NHTSA is proposing the addition of language clarifying that
vehicles required to meet the fuel consumption standards of this part
must also comply with the same requirements as specified in the EPA
regulation 40 CFR 1037.115.
3. 49 CFR Part 535.10(c)
    NHTSA is proposing to delete the 535.10(c)(2) reference to box
trailers, as well as the 535.10(c)(3) reference to manufacturer's
compliance if their trailer meet specified standards, consistent with
the 2021 D.C. Circuit decision, discussed above.

III. Statutory Authority and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.

B. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden
under the PRA. OMB has previously approved the information collection
activities

contained in the existing regulations and has assigned OMB control
numbers 2060-0104, 2060-0287, 2060-0338, 2060-0545, 2060-0641. This
rule clarifies and simplifies procedures without affecting information
collection requirements.

C. Regulatory Flexibility Act (RFA)

    I certify that this action would not have a significant economic
impact on a substantial number of small entities under the RFA. In
making this determination, the impact of concern is any significant
adverse economic impact on small entities. An agency may certify that a
rule will not have a significant economic impact on a substantial
number of small entities if the rule relieves regulatory burden, has no
net burden or otherwise has a positive economic effect on the small
entities subject to the rule. This proposed action is designed to
reduce testing burdens, increase compliance flexibility, and make
various corrections and adjustments to compliance provisions. We
therefore anticipate no costs and no regulatory burden associated with
this proposed rule. We have concluded that this proposed action will
have no significant increase in regulatory burden for directly
regulated small entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. The proposed action imposes no enforceable duty on
any state, local or tribal governments. Requirements for the private
sector do not exceed $100 million in any one year.

E. National Environmental Policy Act (NEPA)

    NHTSA has analyzed this proposed rule for the purposes of the
National Environmental Policy Act. The agency has determined that
implementation of this action will not have any significant impact on
the quality of the human environment.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    This action does not have tribal implications as specified in
Executive Order 13175. This proposed rule will be implemented at the
Federal level and affects engine and vehicle manufacturers. Thus,
Executive Order 13175 does not apply to this action.

H. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    This action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
because there are no environmental health or safety risks created by
this action that could present a disproportionate risk to children.

I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use

    This action is not a ``significant energy action'' because it is
not likely to have a significant adverse effect on the supply,
distribution, or use of energy. We have concluded that this action is
not likely to have any adverse energy effects because it is designed
merely to reduce testing burdens, increase compliance flexibility, and
make various corrections and adjustments to compliance provisions.

J. National Technology Transfer and Advancement Act (NTTAA)

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. NTTAA directs agencies to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards. This action
involves technical standards.

K. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    NHTSA believes this action does not have disproportionately high
and adverse human health or environmental effects on minority
populations, low-income populations or indigenous peoples, as specified
in Executive Order 12898 (59 FR 7629, February 16, 1994). Due to the
lack of environmental impact, these proposed regulatory changes will
not have a disproportionate adverse effect on minority populations,
low-income populations, or indigenous peoples.

IV. Regulatory Text

List of Subjects in 49 CFR Part 535

    Energy conservation, Fuel, Fuel economy, Motor vehicles.

    For the reasons discussed in the preamble, the National Highway
Traffic Safety Administraton proposes to amend 49 CFR part 535 as
follows:

0
1. Revise Part 535 to read as follows:

PART 535--MEDIUM- AND HEAVY-DUTY VEHICLE FUEL EFFICIENCY PROGRAM

Sec.
535.1 Scope.
535.2 Purpose.
535.3 Applicability.
535.4 Definitions.
535.5 Standards.
535.6 Measurement and calculation procedures.
535.7 Averaging, banking, and trading (ABT) credit program.
535.8 Reporting and recordkeeping requirements.
535.9 Enforcement approach.
535.10 How do manufacturers comply with fuel consumption standards?

    Authority:  49 U.S.C. 32902.

Sec.  535.1  Scope.

    This part establishes fuel consumption standards pursuant to 49
U.S.C. 32902(k) for work trucks and commercial medium- and heavy-duty
on-highway vehicles (hereafter referenced as heavy-duty vehicles), and
engines manufactured for sale in the United States. This part
establishes a credit program manufacturers may use to comply with
standards and requirements for manufacturers to provide reports to the
National Highway Traffic Safety Administration regarding their efforts
to reduce the fuel consumption of heavy-duty vehicles and engines.

Sec.  535.2  Purpose.

    The purpose of this part is to reduce the fuel consumption of new
heavy-duty vehicles and engines by establishing maximum levels for fuel
consumption standards while providing a flexible credit program to
assist manufacturers in complying with standards.

Sec.  535.3  Applicability.

    (a) This part applies to manufacturers that produce complete and
incomplete heavy-duty vehicles as defined in 49 CFR part 523, and to
the manufacturers of all heavy-duty engines manufactured for use in the
applicable vehicles for each given model year. Incomplete vehicle
manufacturers must comply with NHTSA's safety requirements in 49 CFR
parts 565, 567 and 568 to comply with part 535. Manufacturers found
under this program not to comply with NHTSA's safety standards or
regulations which apply to the construction of new and incomplete
vehicles in 49 CFR parts 566 through 568 due to incorrect or fraudulent
information will be subject to enforcement in accordance with Chapter
301 of Title 49 and deemed as not complying with Part 535. If the
manufacturer is unable to correct its noncompliance with NHTSA, the
manufacturer fails to comply with the fuel efficiency program and is
unable to earn fuel efficiency credits.
    (b) This part also applies to alterers, final stage manufacturers,
and intermediate manufacturers producing vehicles and engines or
assembling motor vehicles or motor vehicle equipment under special
conditions. Manufacturers comply with this part by following the
special conditions in 40 CFR 1037.620, 1037.621, and 1037.622 in which
EPA allows manufacturer to:
    (1) Share responsibility for the vehicles they produce.
Manufacturers sharing responsibility for complying with emissions and
fuel consumption standards must submit to the agencies a joint
agreement as specified in 49 CFR 534.8(a);
    (2) Have certificate holders sell or ship vehicles that are missing
certain emission-related components to be installed by secondary
vehicle manufacturers;
    (3) Ship partially complete vehicles to secondary manufacturers;
    (4) Build electric vehicles; and
    (5) Build alternative fueled vehicles from all types of heavy-duty
engine conversions. The conversion manufacturer must:
    (i) Install alternative fuel conversion systems into vehicles
acquired from vehicle manufacturers prior to first retail sale or prior
to the vehicle's introduction into interstate commerce.
    (ii) Be designated by the vehicle manufacturer and EPA to be the
certificate holder.
    (iii) Omit alternative fueled vehicles from compliance with vehicle
fuel consumption standards, if-
    (A) Excluded from EPA emissions standards; and
    (B) A reasonable technical basis exist that the modified vehicle
continues to meet emissions and fuel consumption vehicle standards.
    (c) Vehicle and engine manufacturers that must comply with this
part include manufacturers required to have approved certificates of
conformity from EPA as specified in 40 CFR parts 86, 1036, and 1037.
    (d) The following heavy-duty vehicles and engines are excluded from
the requirements of this part:
    (1) Vehicles and engines manufactured prior to January 1, 2014,
unless certified early under NHTSA's voluntary provisions in Sec.
535.5.
    (2) Medium-duty passenger vehicles and other vehicles subject to
the light-duty corporate average fuel economy standards in 49 CFR parts
531 and 533.
    (3) Recreational vehicles, including motor homes manufactured
before January 1, 2021, except those produced by manufacturers
voluntarily complying with NHTSA's early vocational standards for model
years 2013 through 2020.
    (4) Aircraft vehicles meeting the definition of ``motor vehicle''.
For example, this would include certain convertible aircraft that can
be adjusted to operate on public roads.
    (5) Engines installed in heavy-duty vehicles that are not used to
propel vehicles. Note, this includes engines used to indirectly propel
vehicles (such as electrical generator engines that power to batteries
for propulsion).
    (6) The provisions of this part do not apply to engines that are
not internal combustion engines. For example, the provisions of this
part do not apply to fuel cells. Note that gas turbine engines are
internal combustion engines.
    (e) The following heavy-duty vehicles and engines are exempted from
the requirements of this part:
    (1) Off-road vehicles. Vehicle manufacturers producing vehicles
intended for off-road may exempt vehicles without requesting approval
from the agencies subject to the criteria in Sec.  535.5(b)(9)(i) and
40 CFR 1037.631(a). If unusual circumstances exist and a manufacturer
is uncertain as to whether its vehicles qualify, the manufacturer
should ask for a preliminary determination from the agencies before
submitting its application for certification in accordance with 40 CFR
1037.205 for the applicable vehicles. Send the request with supporting
information to EPA and the agencies will coordinate in making a
preliminary determination as specified in 40 CFR 1037.210. These
decisions are considered to be preliminary approvals and subject to
final review and approval.
    (i) Vocational vehicles with a date of manufacture before January
1, 2021 automatically qualify for an exemption under Sec.  1037.631 if
the tires installed on the vehicle have a maximum speed rating at or
below 55 miles per hour.
    (ii) In unusual circumstances, vehicle manufacturers may ask EPA
and NHTSA to exempt vehicles under Sec.  1037.631 based on other
criteria that are equivalent to those specified in Sec.  1037.631(a);
however, the agencies will normally not grant relief in cases where the
vehicle manufacturer has credits or can otherwise comply with
applicable standards. Manufacturers should request approval for an
exemption before producing the subject vehicles. Send your request with
supporting information to the Designated Compliance Officer; EPA will
coordinate in making a determination under Sec.  1037.210. If the
manufacturer introduces into U.S. commerce vehicles that depend on our
approval under this paragraph (h) of this section before we inform you
of our approval, those vehicles violate 40 CFR 1068.101(a)(1) and 40
CFR 535.9.
    (2) Small business manufacturers. (i) For Phase 1, small business
manufacturers are exempted from the vehicle and engine standards of
Sec.  535.5, but must comply with the reporting requirements of Sec.
535.8(g).
    (ii) For Phase 2, fuel consumption standards apply on a delayed
schedule for manufacturers meeting the small business criteria
specified in 13 CFR 121.201 and in 40 CFR 86.1819- 14(k)(5), 40 CFR
1036.150, and 40 CFR 1037.150. Qualifying manufacturers of truck
tractors, vocational vehicles, heavy duty pickups and vans, and engines
are not subject to the fuel consumption standards for vehicles built
before January 1, 2022 and engines (such as those engines built by
small alternative fuel engine converters) with a date of manufacturer
on or after November 14, 2011 and before January 1, 2022. Qualifying
manufacturers may choose to voluntarily comply early.
    (A) Small manufacturers that certify their entire U.S.-directed
production volume to the Phase 1 standards for calendar year 2021 may
certify to the Phase 1 standards for model year 2022 (instead of the
otherwise applicable Phase 2 standards).
    (B) Phase 1 vehicle credits small manufacturers generate under
provision (A) of this section for model year 2018 through 2022
vocational vehicles may be used through model year 2027 (instead of
being subject to a five-year credit life).

    (iii) Small business manufacturers producing vehicles and engines
that run on any fuel other than gasoline, E85, or diesel fuel meeting
the criteria specified in 13 CFR 121.201 and in 40 CFR 86.1819-
14(k)(5), 40 CFR 1036.150, and 40 CFR 1037.150 may delay complying with
every new mandatory standard under this part by one model year.
    (3) Engines for specialty vehicles. Engines certified to the
alternative standards specified in 40 CFR 86.007-11 and 86.008-10 for
use in specialty vehicles as described in 40 CFR 1037.605. Compliance
with the vehicle provisions in 40 CFR 1037.605 satisfies compliance for
NHTSA under this part.
    (f) For model year 2021 and later, vocational vehicle manufacturers
building custom chassis vehicles (e.g., emergency vehicles) may be
exempted from standards in Sec.  535.5(b)(4) and may comply with
alternative fuel consumption standards as specified in Sec.
535.5(b)(6). Manufacturers complying with alternative fuel consumption
standards in Sec.  535.5(b)(6) are restricted in using fuel consumption
credits as specified in Sec.  535.7(c).
    (g) The fuel consumption standards in some cases apply differently
for spark-ignition and compression-ignition engines or vehicles as
specified in 40 CFR parts 1036 and 1037. Engine requirements are
similarly differentiated by engine type and by primary intended service
class, as described in 40 CFR 1036.140.
    (h) NHTSA may exclude or exempt vehicles and engines under special
conditions allowed by EPA in accordance with 40 CFR parts 85, 86, 1036,
1037, 1039, and 1068. Manufacturers should consult the agencies if
uncertain how to apply any EPA provision under the NHTSA fuel
consumption program. It is recommended that manufacturers seek
clarification before producing a vehicle. Upon notification by EPA of a
fraudulent use of an exemption, NHTSA reserves that right to suspend or
revoke any exemption or exclusion.
    (i) In cases where there are differences between the application of
this part and the corresponding EPA program regarding whether a vehicle
is regulated or not (such as due to differences in applicability
resulting from differing agency definitions, etc.), manufacturers
should contact the agencies to identify these vehicles and assess the
applicability of the agencies' standards. The agencies will provide
guidance on how the vehicles can comply. Manufacturers are required to
identify these vehicles in their final reports submitted in accordance
with Sec.  535.8.
    (j) If EPA denies, suspends or revokes, a manufacturer's
certificate of conformity in accordance with 40 CFR 1036.255 or
1037.225, due to incomplete, incorrect or fraudulent information, the
vehicles or engines covered by the applicable certificate will be:
    (1) ineligible to participate in the NHTSA fuel consumption program
if the certificate is denied.
    (2) eligible only for partial crediting under Sec.  535.7, for the
population of vehicles or engines which the certificate remains in
effect before the date of the suspension. The population of vehicle or
engines after the suspension may also be subject to possible fines in
accordance with Sec.  535.9.
    (3) ineligible for crediting under Sec.  535.7, and subject to
possible fines in accordance with Sec.  535.9 if fraud exists.
    (4) If NHTSA finds a manufacturer has submitted incomplete,
incorrect or fraudulent information, it will contact EPA to deliberate
and determine the appropriate enforcement action.

Sec.  535.4  Definitions.

    The terms manufacture and manufacturer are used as defined in
section 501 of the Act and the terms commercial medium-duty and heavy-
duty on highway vehicle, fuel and work truck are used as defined in 49
U.S.C. 32901. See 49 CFR 523.2 for general definitions related to
NHTSA's fuel efficiency programs.
    Act means the Motor Vehicle Information and Cost Savings Act, as
amended by Public Law 94-163 and 96-425.
    Adjustable parameter has the meaning given in 40 CFR 1037.801.
    Administrator means the Administrator of the National Highway
Traffic Safety Administration (NHTSA) or the Administrator's delegate.
    Advanced technology means vehicle technology under this fuel
consumption program in Sec.  535.6 and 535.7 and by EPA under 40 CFR
86.1819-14(d)(7), 1036.615, or 1037.615.
    Alterers means a manufacturer that modifies an altered vehicle as
defined in 49 CFR 567.3.
    Alternative fuel conversion has the meaning given for clean
alternative fuel conversion in 40 CFR 85.502.
    Alternative fuel conversion has the meaning given in 40 CFR 85.502.
    A to B testing has the meaning given in 40 CFR 1037.801.
    Automated manual transmission has the meaning given in 40 CFR
1037.801.
    Automatic tire inflation system has the meaning given in 40 CFR
1037.801.
    Automatic transmission (AT) has the meaning given in 40 CFR
1037.801.
    Auxiliary power unit has the meaning given in 40 CFR 1037.801.
    Averaging set means, a set of engines or vehicles in which fuel
consumption credits may be exchanged. Credits generated by one engine
or vehicle family may only be used by other respective engine or
vehicle families in the same averaging set as specified in Sec.  535.7.
Note that an averaging set may comprise more than one regulatory
subcategory. The averaging sets for this HD program are defined as
follows:
    (1) Heavy-duty pickup trucks and vans.
    (2) Light heavy-duty (LHD) vehicles.
    (3) Medium heavy-duty (MHD) vehicles.
    (4) Heavy heavy-duty (HHD) vehicles.
    (5) Light heavy-duty engines subject to compression-ignition
standards.
    (6) Medium heavy-duty engines subject to compression-ignition
standards.
    (7) Heavy heavy-duty engines subject to compression-ignition
standards.
    (8) Engines subject to spark-ignition standards.
    (9) Vehicle types certifying to optional custom chassis standards
as specified in Sec.  535.5(b)(6) form separate averaging sets for each
vehicle type as specified in Sec.  535.7(c).
    Axle ratio or Drive axle ratio, ka has the meaning given in 40 CFR
1037.801.
    Basic vehicle frontal area has the meaning given in 40 CFR
1037.801.
    Cab-complete vehicle has the meaning given in 49 CFR 523.2.
    Carryover has the meaning given in 40 CFR 1037.801.
    Certificate holder means the manufacturer who holds the certificate
of conformity for the vehicle or engine and that assigns the model year
based on the date when its manufacturing operations are completed
relative to its annual model year period.
    Certificate of Conformity means an approval document granted by EPA
to a manufacturer that submits an application for a vehicle or engine
emissions family in 40 CFR 1036.205 and 1037.205. A certificate of
conformity is valid from the indicated effective date until December 31
of the model year for which it is issued. The certificate must be
renewed annually for any vehicle a manufacturer continues to produce.
Information included in an amended application made in accordance with
40 CFR part 1036.225 and 1037.225, before the end of the model year
applies similarly to the NHTSA fuel consumption program as to the EPA.
If a manufacturer amends its application to make the amended
application correct and complete, these changes do not apply
retroactively to

the NHTSA fuel efficiency program. Also, if EPA or NHTSA determines
that the manufacturer's amended application is not correct and
complete, or otherwise does not conform to its regulations, any changes
finalized by EPA or if EPA suspends, revokes, or voids a certification,
also applies to the NHTSA fuel efficiency program. See Sec.  535.3(j).
    Certification has the meaning given in 40 CFR 1037.801.
    Certified emission level has the meaning given in 40 CFR 1036.801.
    Chassis-cab means the incomplete part of a vehicle that includes a
frame, a completed occupant compartment and that requires only the
addition of cargo-carrying, work-performing, or load- bearing
components to perform its intended functions.
    Chief Counsel means the NHTSA Chief Counsel, or his or her
designee.
    Class means relating to GVWR classes for vehicles other than
trailers, as follows:
    (1) Class 2b vehicles are vehicles with a gross vehicle weight
rating (GVWR) ranging from 8,501 to 10,000 pounds.
    (2) Class 3 through Class 8 vehicles are vehicles with a gross
vehicle weight rating (GVWR) of 10,001 pounds or more as defined in 49
CFR 565.15.
    Complete sister vehicle is a complete vehicle of the same
configuration as a cab-complete vehicle.
    Complete vehicle has the meaning given in 49 CFR part 523.
    Compression-ignition (CI) means relating to a type of
reciprocating, internal-combustion engine, such as a diesel engine,
that is not a spark-ignition engine. Note, in accordance with 40 CFR
1036.1, gas turbine engines and other engines not meeting the
definition of compression-ignition are deemed to be compression-
ignition engines for complying with fuel consumption standards.
    Configuration means a subclassification within a test group for
passenger cars, light trucks and medium-duty passenger vehicles and
heavy-duty pickup trucks and vans which is based on basic engine,
engine code, transmission type and gear ratios, and final drive ratio.
    Container chassis trailer has the same meaning as container chassis
in 40 CFR 1037.801.
    Curb weight has the meaning given in 40 CFR 86.1803.
    Custom chassis vehicle means a vocational vehicle that is a motor
home, school bus, refuse hauler, concrete mixer, emergency vehicle,
mixed-use vehicle or other buses that are not school buses or motor
coaches. These vehicle types are defined in 49 CFR 523.3. A ``mixed-use
vehicle'' is one that meets at least one of the criteria specified in
40 CFR 1037.631(a)(1) or at least one of the criteria in 40 CFR
1037.631(a)(2), but not both.
    Date of manufacture means the date on which the certifying vehicle
manufacturer completes its manufacturing operations, except as follows:
    (1) Where the certificate holder is an engine manufacturer that
does not manufacture the complete or incomplete vehicle, the date of
manufacture of the vehicle is based on the date assembly of the vehicle
is completed.
    (2) EPA and NHTSA may approve an alternate date of manufacture
based on the date on which the certifying (or primary) vehicle
manufacturer completes assembly at the place of main assembly,
consistent with the provisions of 40 CFR 1037.601 and 49 CFR 567.4.
    (3) A vehicle manufacturer that completes assembly of a vehicle at
two or more facilities may ask to use as the month and year of
manufacture, for that vehicle, the month and year in which
manufacturing is completed at the place of main assembly, consistent
with provisions of 49 CFR 567.4, as the model year. Note that such
staged assembly is subject to the provisions of 40 CFR 1068.260(c).
NHTSA's allowance of this provision is effective when EPA approves the
manufacturer's certificates of conformity for these vehicles.
    Day cab has the meaning given in 40 CFR 1037.801.
    Drayage tractor has the meaning given in 40 CFR 1037.801.
    Dual-clutch transmission (DCT) means a transmission has the meaning
given in 40 CFR 1037.801.
    Dual-fuel has the meaning given in 40 CFR 1037.801.
    Electric vehicle has the meaning given in 40 CFR 1037.801.
    Emergency vehicle means a vehicle that meets one of the criteria in
40 CFR 1037.801.
    Emission data engine has the meaning given in 40 CFR 1036.801.
    Engine configuration has the meaning given in 40 CFR 1036.801.
    Engine family has the meaning given in 40 CFR 1036.230.
Manufacturers designate families in accordance with EPA provisions and
may not choose different families between the NHTSA and EPA programs.
    Excluded means a vehicle or engine manufacturer or component is not
required to comply with any aspects with the NHTSA fuel consumption
program.
    Exempted means a vehicle or engine manufacturer or component is not
required to comply with certain provisions of the NHTSA fuel
consumption program.
    Family certification level (FCL) has the meaning given in 40 CFR
1036.801.
    Family emission limit (FEL) has the meaning given in 40 CFR
1037.801.
    Final drive ratio has the meaning given in 40 CFR 1037.801.
    Final-stage manufacturer has the meaning given in 49 CFR 567.3 and
includes secondary vehicle manufacturers as defined in 40 CFR 1037.801.
    Fleet in this part means all the heavy-duty vehicles or engines
within each of the regulatory sub- categories that are manufactured by
a manufacturer in a particular model year and that are subject to fuel
consumption standards under Sec.  535.5.
    Fleet average fuel consumption is the calculated average fuel
consumption performance value for a manufacturer's fleet derived from
the production weighted fuel consumption values of the unique vehicle
configurations within each vehicle model type that makes up that
manufacturer's vehicle fleet in a given model year. In this part, the
fleet average fuel consumption value is determined for each
manufacturer's fleet of heavy-duty pickup trucks and vans.
    Fleet average fuel consumption standard is the actual average fuel
consumption standard for a manufacturer's fleet derived from the
production weighted fuel consumption standards of each unique vehicle
configuration, based on payload, tow capacity and drive configuration
(2, 4 or all- wheel drive), of the model types that makes up that
manufacturer's vehicle fleet in a given model year. In this part, the
fleet average fuel consumption standard is determined for each
manufacturer's fleet of heavy-duty pickup trucks and vans.
    Flexible-fuel has the meaning given in 40 CFR 1036.801.
    Fuel cell means an electrochemical cell that produces electricity
via the non-combustion reaction of a consumable fuel, typically
hydrogen.
    Fuel cell electric vehicle means a motor vehicle propelled solely
by an electric motor where energy for the motor is supplied by a fuel
cell.
    Fuel efficiency means the amount of work performed for each gallon
of fuel consumed.
    Fuel type has the meaning given in 40 CFR 1037.801.
    Gaseous fuel has the meaning given in 40 CFR 1037.801.
    Gear ratio or Transmission gear ratio, kg, has the meaning given in
40 CFR 1037.801.

    Good engineering judgment has the meaning given in 40 CFR 1068.30.
See 40 CFR 1068.5 for the administrative process used to evaluate good
engineering judgement.
    Greenhouse gas has the meaning given in 40 CFR 1036.801.
    Greenhouse gas Emissions Model (GEM) has the meaning given in 40
CFR 1037.801.
    Gross axle weight rating (GAWR) has the meaning given in 49 CFR
571.3.
    Gross combination weight rating (GCWR) has the meaning given in 49
CFR 571.3.
    Gross vehicle weight rating (GVWR) has the meaning given in 49 CFR
571.3.
    Heavy-duty off-road vehicle means a heavy-duty vocational vehicle
or vocational tractor that is intended for off-road use.
    Heavy-duty engine has the meaning given in 40 CFR 1036.801 and 49
CFR part 523.
    Heavy-duty vehicle has the meaning given in 40 CFR 1036.801 and 49
CFR part 523.
    Heavy-haul tractor has the meaning given in 40 CFR 1037.801 and 49
CFR part 523.
    Heavy heavy-duty (HHD) vehicle has the meaning given in vehicle
service class.
    Hybrid has the meaning given in 40 CFR 1036.801.
    Hybrid engine or hybrid powertrain has the meaning given in 40 CFR
1037.801.
    Hybrid vehicle has the meaning given in 40 CFR 1037.801.
    Identification number has the meaning given in 40 CFR 1037.801.
    Idle operation has the meaning given in 40 CFR 1037.801.
    Incomplete vehicle has the meaning given in 49 CFR part 523. For
the purpose of this regulation, a manufacturer may request EPA and
NHTSA to allow the certification of a vehicle as an incomplete vehicle
if it manufactures the engine and sells the unassembled chassis
components, provided it does not produce and sell the body components
necessary to complete the vehicle.
    Innovative technology means technology certified under Sec.  535.7
and by EPA under 40 CFR 86.1819-14(d)(13), 1036.610, and 1037.610 in
the Phase 1 program.
    Intermediate manufacturer has the meaning given in 49 CFR 567.3.
    Light heavy-duty (LHD) vehicle has the meaning given in vehicle
service class.
    Liquefied petroleum gas (LPG) has the meaning given in 40 CFR
1036.801.
    Low rolling resistance tire means a tire on a vocational vehicle
with a tire rolling resistance level (TRRL) of 7.7 kg/metric ton or
lower, a steer tire on a tractor with a TRRL of 7.7 kg/metric ton or
lower, or a drive tire on a tractor with a TRRL of 8.1 kg/metric ton or
lower.
    Manual transmission (MT) has the meaning given in 40 CFR 1037.801.
    Manufacturer has the meaning given in 40 CFR 1036.801.
    Medium heavy-duty (MHD) vehicle has the meaning given in vehicle
service class.
    Model type has the meaning given in 40 CFR 600.002.
    Model year as it applies to vehicles means:
    (1) For tractors and vocational vehicles with a date of manufacture
on or after January 1, 2021, the vehicle's model year is the calendar
year corresponding to the date of manufacture; however, the vehicle's
model year may be designated to be the year before the calendar year
corresponding to the date of manufacture if the engine's model year is
also from an earlier year. Note that paragraph (2) of this definition
limits the extent to which vehicle manufacturers may install engines
built in earlier calendar years. Note that 40 CFR 1037.601(a)(2) limits
the extent to which vehicle manufacturers may install engines built in
earlier calendar years.
    (2) For Phase 1 tractors and vocational vehicles with a date of
manufacture before January 1, 2021, model year means the manufacturer's
annual new model production period, except as restricted under this
definition. It must include January 1 of the calendar year for which
the model year is named, may not begin before January 2 of the previous
calendar year, and it must end by December 31 of the named calendar
year. The model year may be set to match the calendar year
corresponding to the date of manufacture.
    (i) The manufacturer who holds the certificate of conformity for
the vehicle must assign the model year based on the date when its
manufacturing operations are completed relative to its annual model
year period. In unusual circumstances where completion of your assembly
is delayed, we may allow you to assign a model year one year earlier,
provided it does not affect which regulatory requirements will apply.
    (ii) Unless a vehicle is being shipped to a secondary manufacturer
that will hold the certificate of conformity, the model year must be
assigned prior to introduction of the vehicle into U.S. commerce. The
certifying manufacturer must re-designate the model year if it does not
complete its manufacturing operations within the originally identified
model year. A vehicle introduced into U.S. commerce without a model
year is deemed to have a model year equal to the calendar year of its
introduction into U.S. commerce unless the certifying manufacturer
assigns a later date.
    Model year as it applies to engines means the manufacturer's annual
new model production period, except as restricted under this
definition. It must include January 1 of the calendar year for which
the model year is named, may not begin before January 2 of the previous
calendar year, and it must end by December 31 of the named calendar
year. Manufacturers may not adjust model years to circumvent or delay
compliance with emission standards or to avoid the obligation to
certify annually.
    (1) The following provisions apply for production and ABT reports
during the transition to engine-based model year determinations for
tractors and vocational vehicles in 2020 and 2021:
    (i) If a manufacturer installs model year 2020 or earlier engines
in its vehicles in calendar year 2020, the manufacturers should include
all those Phase 1 vehicles in its production and ABT reports related to
model year 2020 compliance, although EPA may require the manufacturer
to identify these separately from vehicles produced in calendar year
2019.
    (ii) If a manufacturer installs model year 2020 engines in its
vehicles in calendar year 2021, the manufacturer should submit
production and ABT reports for those Phase 1 vehicles separate from the
reports it submits for Phase 2 vehicles with model year 2021 engines.
    Motor Vehicle has the meaning given in 49 U.S.C. 32901.
    Multi-purpose has the meaning given in 40 CFR 1037.801.
    Natural gas has the meaning given in 40 CFR 1036.801. Vehicles that
use a pilot-ignited natural gas engine (which uses a small diesel fuel
ignition system), are still considered natural gas vehicles.
    NHTSA Enforcement means the NHTSA Associate Administrator for
Enforcement, or his or her designee.
    Neutral coasting has the meaning given in 40 CFR 1037.801.
    Neutral idle has the meaning given in 40 CFR 1037.801.
    New vehicles has the meaning given to ``new motor vehicle''
provided in 40 CFR 1037.801.
    Off-cycle technology means technology certified under Sec.  535.7
and by EPA under 40 CFR 86.1819-14(d)(13), 1036.610, and 1037.610 in
the Phase 2 program.

    Party means the person alleged to have committed a violation of
Sec.  535.9, and includes manufacturers of vehicles and manufacturers
of engines.
    Payload means in this part the resultant of subtracting the curb
weight from the gross vehicle weight rating.
    Percent has the meaning given in 40 CFR 1036.801.
    Petroleum has the meaning given in 40 CFR 1037.801.
    Phase 1 means the joint NHTSA and EPA program established in 2011
for fuel efficiency standards and greenhouse gas emissions standards
regulating medium- and heavy-duty engines and vehicles. See Sec.  535.5
for the specific model years that standards apply to vehicles and
engines.
    Phase 2 means the joint NHTSA and EPA program established in 2016
for fuel efficiency standards and greenhouse gas emissions standards
regulating medium- and heavy-duty vehicles and engines. See Sec.  535.5
for the specific model years that standards apply to vehicles and
engines.
    Pickup truck has the meaning given in 49 CFR part 523.
    Placed into service has the meaning given in 40 CFR 1037.801.
    Plug-in hybrid electric vehicle (PHEV) means a hybrid electric
vehicle that has the capability to charge the battery or batteries used
for vehicle propulsion from an off-vehicle electric source, such that
the off-vehicle source cannot be connected to the vehicle while the
vehicle is in motion.
    Power take-off (PTO) means a secondary engine shaft or other system
on a vehicle that provides substantial auxiliary power for purposes
unrelated to vehicle propulsion or normal vehicle accessories such as
air conditioning, power steering, and basic electrical accessories. A
typical PTO uses a secondary shaft on the engine to transmit power to a
hydraulic pump that powers auxiliary equipment such as a boom on a
bucket truck.
    Powertrain family has the meaning given in 40 CFR 1037.231.
Manufacturers choosing to perform powertrain testing as specified in 40
CFR 1037.550, divide product lines into powertrain families that are
expected to have similar fuel consumptions and CO2 emission
characteristics throughout the useful life.
    Preliminary approval means approval granted by an authorized EPA
representative prior to submission of an application for certification,
consistent with the provisions of 40 CFR 1037.210. For requirements
involving NHTSA, EPA will ensure decisions are jointly made and will
convey the decision to the manufacturer.
    Primary intended service class has the same meaning for engines as
specified in 40 CFR 1036.140. Manufacturers must identify a single
primary intended service class for each engine family that best
describes vehicles for which it designs and markets the engine, as
follows:
    (1) Divide compression-ignition engines into primary intended
service classes based on the following engine and vehicle
characteristics:
    (i) Light heavy-duty ``LHD'' engines usually are not designed for
rebuild and do not have cylinder liners. Vehicle body types in this
group might include any heavy-duty vehicle built from a light-duty
truck chassis, van trucks, multi-stop vans, and some straight trucks
with a single rear axle. Typical applications would include personal
transportation, light-load commercial delivery, passenger service,
agriculture, and construction. The GVWR of these vehicles is normally
below 19,500 pounds.
    (ii) Medium heavy-duty ``MHD'' engines may be designed for rebuild
and may have cylinder liners. Vehicle body types in this group would
typically include school buses, straight trucks with single rear axles,
city tractors, and a variety of special purpose vehicles such as small
dump trucks, and refuse trucks. Typical applications would include
commercial short haul and intra- city delivery and pickup. Engines in
this group are normally used in vehicles whose GVWR ranges from 19,500
to 33,000 pounds.
    (iii) Heavy heavy-duty ``HHD'' engines are designed for multiple
rebuilds and have cylinder liners. Vehicles in this group are normally
tractors, trucks, straight trucks with dual rear axles, and buses used
in inter-city, long-haul applications. These vehicles normally exceed
33,000 pounds GVWR.
    (2) Divide spark-ignition engines into primary intended service
classes as follows:
    (i) Spark-ignition engines that are best characterized by paragraph
(1)(i) or (ii) of this section are in a separate ``spark-ignition''
primary intended service class.
    (ii) Spark-ignition engines that are best characterized by
paragraph (1)(iii) of this section share a primary intended service
class with compression-ignition heavy heavy-duty engines. Gasoline-
fueled engines are presumed not to be characterized by paragraph
(1)(iii) of this section; for example, vehicle manufacturers may
install some number of gasoline-fueled engines in Class 8 trucks
without causing the engine manufacturer to consider those to be heavy
heavy-duty engines.
    (iii) References to ``spark-ignition standards'' in this part
relate only to the spark-ignition engines identified in paragraph
(b)(1) of this section. References to ``compression-ignition
standards'' in this part relate to compression-ignition engines, to
spark-ignition engines optionally certified to standards that apply to
compression-ignition engines, and to all engines identified under
paragraph (b)(2) of this section as heavy heavy-duty engines.
    Rechargeable Energy Storage System (RESS) means the component(s) of
a hybrid engine or vehicle that store recovered energy for later use,
such as the battery system in a electric hybrid vehicle.
    Refuse hauler has the meaning given in 40 CFR 1037.801.
    Regional has the meaning relating to the Regional duty cycle as
specified in 40 CFR 1037.510.
    Regulatory category means each of the four types of heavy-duty
vehicles defined in 49 CFR 523.6 and the heavy-duty engines used in
these heavy-duty vehicles.
    Regulatory subcategory means the sub-groups in each regulatory
category to which mandatory fuel consumption standards and requirements
apply as specified in 40 CFR 1036.230 and 1037.230 and are defined as
follows:
    (1) Heavy-duty pick-up trucks and vans.
    (2) Vocational vehicle subcategories have 18 separate vehicle
service classes as shown in Tables 1 and 2 below and include vocational
tractors. Table 1 includes vehicles complying with Phase 1 standards.
Phase 2 vehicles are included in Table 2 which have separate
subcategories to account for engine characteristics, GVWR, and the
selection of duty cycle for vocational vehicles as specified in 40 CFR
1037.510; vehicles may additionally fall into one of the subcategories
defined by the custom-chassis standards in Sec.  535.5(b)(6) and 40
1037.105(h). Manufacturers using the alternate standards in Sec.
535.5(b)(6) and 40 CFR 1037.105(h) should treat each vehicle type as a
separate vehicle subcategory.

            Table 1--Phase 1 Vocational Vehicle Subcategories
------------------------------------------------------------------------

-------------------------------------------------------------------------
Vocational LHD vehicles.
Vocational MHD vehicles.
Vocational HHD vehicles.
------------------------------------------------------------------------

            Table 2--Phase 2 Vocational Vehicle Subcategories
------------------------------------------------------------------------
                        Vocational LHD   Vocational MHD   Vocational HHD
     Engine type           vehicles         vehicles         vehicles
------------------------------------------------------------------------
CI...................  Urban..........  Urban..........  Urban.
CI...................  Multi-Purpose..  Multi-Purpose..  Multi-Purpose.
CI...................  Regional.......  Regional.......  Regional.
SI...................  Urban..........  Urban..........
SI...................  Multi-Purpose..  Multi-Purpose..
SI...................  Regional.......  Regional.......
------------------------------------------------------------------------

    (3) Tractor subcategories are shown in Table 3 below for Phase 1
and 2. Table 3 includes 10 separate subcategories for tractors
complying with Phase 1 and 2 standards. The heavy-haul tractor
subcategory only applies for Phase 2.

           Table 3--Phase 1 and 2 Truck Tractor Subcategories
------------------------------------------------------------------------
                                                        Class 8 sleeper
             Class 7               Class 8 day cabs          cabs
------------------------------------------------------------------------
Low-roof tractors...............  Low-roof day cab    Low-roof sleeper
                                   tractors.           cab tractors.
Mid-roof tractors...............  Mid-roof day cab    Mid-roof sleeper
                                   tractors.           cab tractors.
High-roof tractors..............  High-roof day cab   High-roof sleeper
                                   tractors.           cab tractors.
                                 ---------------------------------------
                                   Heavy-haul tractors (applies only to
                                             Phase 2 program).
------------------------------------------------------------------------

    (5) Engine subcategories are shown for each primary intended
service class in Table 5 below. Table 5 includes 6 separate
subcategories for engines which are the same for Phase 1 and 2
standards.

                      Table 5--Engine Subcategories
------------------------------------------------------------------------
           LHD engines                MHD engines         HHD engines
------------------------------------------------------------------------
CI engines for vocational         CI engines for      CI engines for
 vehicles.                         vocational          vocational
                                   vehicles.           vehicles.
                                  CI engines for      CI engines for
                                   truck tractors.     truck tractors.
-----------------------------------------------------
             All spark-ignition engines.
------------------------------------------------------------------------

    Relating to has the meaning given in 40 CFR 1037.801.
    Revoke has the same meaning given in 40 CFR 1068.30.
    Roof height means the maximum height of a vehicle (rounded to the
nearest inch), excluding narrow accessories such as exhaust pipes and
antennas, but including any wide accessories such as roof fairings.
Measure roof height of the vehicle configured to have its maximum
height that will occur during actual use, with properly inflated tires
and no driver, passengers, or cargo onboard. Determine the base roof
height on fully inflated tires having a static loaded radius equal to
the arithmetic mean of the largest and smallest static loaded radius of
tires a manufacturer offers or a standard tire EPA approves. If a
vehicle is equipped with an adjustable roof fairing, measure the roof
height with the fairing in its lowest setting. Once the maximum height
is determined, roof heights are divided into the following categories:
    (1) Low-roof means a vehicle with a roof height of 120 inches or
less.
    (2) Mid-roof means a vehicle with a roof height between 121 and 147
inches.
    (3) High-roof means a vehicle with a roof height of 148 inches or
more.
    Round has the meaning given in 40 CFR 1065.1001.
    Secondary vehicle manufacturer has the same meaning as final-stage
manufacturer in 49 CFR part 567.
    Service class group means a group of engine and vehicle averaging
sets defined as follows:
    (1) Spark-ignition engines, light heavy-duty compression-ignition
engines, light heavy-duty vocational vehicles and heavy-duty pickup
trucks and vans.
    (2) Medium heavy-duty compression-ignition engines and medium
heavy-duty vocational vehicles and tractors.
    (3) Heavy heavy-duty compression-ignition engines and heavy heavy-
duty vocational vehicles and tractors.
    Sleeper cab means a type of truck cab that has a compartment behind
the driver's seat intended to be used by the driver for sleeping. This
includes both cabs accessible from the driver's compartment and those
accessible from outside the vehicle.
    Small business manufacturer means a manufacturer meeting the
criteria specified in 13 CFR 121.201. For manufacturers owned by a
parent company, the employee and revenue limits apply to the total
number employees and total revenue of the parent company and all its
subsidiaries.
    Spark-ignition (SI) means relating to a gasoline-fueled engine or
any other type of engine with a spark plug (or other sparking device)
and with operating characteristics significantly similar to the
theoretical Otto combustion cycle. Spark-ignition engines usually use a
throttle to regulate intake air flow to control power during normal
operation. Note that some spark-ignition engines are subject to
requirements that apply for compression-ignition engines as described
in 40 CFR 1036.140.
    Standard payload means the payload assumed for each vehicle, in
tons, for modeling and calculating emission credits, as follows:
    (1) For vocational vehicles:
    (i) 2.85 tons for light heavy-duty vehicles.
    (ii) 5.6 tons for medium heavy-duty vehicles.
    (iii) 7.5 tons for heavy heavy-duty vocational vehicles.
    (2) For tractors:
    (i) 12.5 tons for Class 7.

    (ii) 19 tons for Class 8.
    (iii) 43 tons for heavy-haul tractors.
    Standard tractor has the meaning given in 40 CFR 1037.801.
    Standard trailer has the meaning given in 40 CFR 1037.801.
    Stop start has the meaning given in 40 CFR 1037.801
    Subconfiguration means a unique combination within a vehicle
configuration of equivalent test weight, road-load horsepower, and any
other operational characteristics or parameters that EPA determines may
significantly affect CO2 emissions within a vehicle configuration as
defined in 40 CFR 600.002.
    Suspend has the meaning given in 40 CFR 1037.801.
    Tank trailer has the meaning given in 40 CFR 1037.801.
    Test group means the multiple vehicle lines and model types that
share critical emissions and fuel consumption related features and that
are certified as a group by a common certificate of conformity issued
by EPA and is used collectively with other test groups within an
averaging set or regulatory subcategory and is used by NHTSA for
determining the fleet average fuel consumption.
    The agencies means the National Highway Traffic Safety
Administration (NHTSA) and the Environmental Protection Agency (EPA) in
this part.
    Tire pressure monitoring system (TPMS) has the meaning given in
section S3 of 49 CFR 571.138.
    Tire rolling resistance level (TRRL) means a value with units of
kg/metric ton that represents that rolling resistance of a tire
configuration. TRRLs are used as inputs to the GEM model under 40 CFR
1037.520. Note that a manufacturer may assign a value higher than a
measured rolling resistance of a tire configuration.
    Towing capacity in this part is equal to the resultant of
subtracting the gross vehicle weight rating from the gross combined
weight rating.
    Trade means to exchange fuel consumption credits, either as a buyer
or a seller.
    U.S.-directed production volume means the number of vehicle units,
subject to the requirements of this part, produced by a manufacturer
for which the manufacturer has a reasonable assurance that sale was or
will be made to ultimate purchasers in the United States.
    Useful life has the meaning given in 40 CFR 1036.801 and 1037.801.
    Vehicle configuration means a unique combination of vehicle
hardware and calibration (related to measured or modeled emissions)
within a vehicle family as specified in 40 CFR 1037.801.
    Vehicles with hardware or software differences, but that have no
hardware or software differences related to measured or modeled
emissions or fuel consumption can be included in the same vehicle
configuration. Note that vehicles with hardware or software differences
related to measured or modeled emissions or fuel consumption are
considered to be different configurations even if they have the same
GEM inputs and FEL. Vehicles within a vehicle configuration differ only
with respect to normal production variability or factors unrelated to
measured or modeled emissions and fuel consumption for EPA and NHTSA.
    Vehicle family has the meaning given in 40 CFR 1037.230.
Manufacturers designate families in accordance with EPA provisions and
may not choose different families between the NHTSA and EPA programs.
If a manufacturer is certifying vehicles within a vehicle family to
more than one FEL, it must subdivide its greenhouse gas and fuel
consumption vehicle families into subfamilies that include vehicles
with identical FELs. Note that a manufacturer may add subfamilies at
any time during the model year.
    Vehicle service class has the same meaning for vehicles as
specified in 40 CFR 1037.140.
    Vehicle subfamily or subfamily means a subset of a vehicle family
including vehicles subject to the same FEL(s).
    Vocational tractor has the meaning given in 40 CFR 1037.801.
    Void has the meaning given in 40 CFR 1036.30.
    Zero emissions vehicle means an electric vehicle or a fuel cell
vehicle.

Sec.  535.5  Standards.

    (a) Heavy-duty pickup trucks and vans. Each manufacturer's fleet of
heavy-duty pickup trucks and vans shall comply with the fuel
consumption standards in this paragraph (a) expressed in gallons per
100 miles. Each vehicle must be manufactured to comply for its full
useful life. For the Phase 1 program, if the manufacturer's fleet
includes conventional vehicles (gasoline, diesel and alternative fueled
vehicles) and advanced technology vehicles (hybrids with powertrain
designs that include energy storage systems, vehicles with waste heat
recovery, electric vehicles and fuel cell vehicles), it may divide its
fleet into two separate fleets each with its own separate fleet average
fuel consumption standard which the manufacturer must comply with the
requirements of this paragraph (a). For Phase 2, manufacturers may
calculate their fleet average fuel consumption standard for a
conventional fleet and multiple advanced technology vehicle fleets.
Advanced technology vehicle fleets should be separated into plug-in
hybrid electric vehicles, electric vehicles and fuel cell vehicles. The
standards in this paragraph (a) correspond to the same requirements for
EPA as specified in 40 CFR 86.1819-14. Manufacturers must apply the
fuel consumption standards in this paragraph (a) to the same vehicles
and engines using the same options used to comply with EPA in 40 CFR
part 86, subpart S. Engines that comply to the standards in this
paragraph are not allowed to comply with the standards in paragraph (d)
of this section.
    (1) Mandatory standards. For model years 2016 and later, each
manufacturer must comply with the fleet average standard derived from
the unique subconfiguration target standards (or groups of
subconfigurations approved by EPA in accordance with 40 CFR 86.1819) of
the model types that make up the manufacturer's fleet in a given model
year. Each subconfiguration has a unique attribute-based target
standard, defined by each group of vehicles having the same payload,
towing capacity and whether the vehicles are equipped with a 2-wheel or
4-wheel drive configuration. Phase 1 target standards apply for model
years 2016 through 2020. Phase 2 target standards apply for model year
2021 and afterwards.
    (2) Subconfiguration target standards.
    (i) Two alternatives exist for determining the subconfiguration
target standards for Phase 1. For each alternative, separate standards
exist for compression-ignition and spark-ignition vehicles:
    (A) The first alternative allows manufacturers to determine a fixed
fuel consumption standard that is constant over the model years; and
    (B) The second alternative allows manufacturers to determine
standards that are phased-in gradually each year.
    (ii) Calculate the subconfiguration target standards as specified
in this paragraph (a)(2)(ii) of this section, using the appropriate
coefficients from Table 6 choosing between the alternatives in
paragraph (a)(2)(i) of this section. For electric or fuel cell heavy-
duty vehicles, use compression-ignition vehicle coefficients ``c'' and
``d'' and for hybrid (including plug-in hybrid), dedicated and dual-
fueled vehicles, use coefficients ``c'' and ``d'' appropriate for the
engine type used. Round each standard to the nearest 0.001 gallons per
100 miles and specify all weights in pounds rounded to the nearest
pound. Calculate the subconfiguration target standards using the
following equation:

Subconfiguration Target Standard (gallons per 100 miles) = [c x (WF)] +
d

Where:

WF = Work Factor = [0.75 x (Payload Capacity + Xwd)] + [0.25 x
Towing Capacity]
Xwd = 4wd Adjustment = 500 lbs if the vehicle group is equipped with
4wd and all-wheel drive, otherwise equals 0 lbs for 2wd.
Payload Capacity = GVWR (lbs)-Curb Weight (lbs) (for each vehicle
group) Towing
Capacity = GCWR (lbs)-GVWR (lbs) (for each vehicle group)

                      Table 6--Coefficients for Mandatory Subconfiguration Target Standards
----------------------------------------------------------------------------------------------------------------
                         Model year(s)                                     c                        d
----------------------------------------------------------------------------------------------------------------
                                  Phase 1 Alternative 1--Fixed Target Standards
----------------------------------------------------------------------------------------------------------------
                                             CI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2016 to 2018..................................................                0.0004322                    3.330
2019 to 2020..................................................                0.0004086                    3.143
----------------------------------------------------------------------------------------------------------------
                                             SI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2016 to 2017..................................................                0.0005131                    3.961
2018 to 2020..................................................                0.0004086                    3.143
----------------------------------------------------------------------------------------------------------------
                                Phase 1 Alternative 2--Phased-in Target Standards
----------------------------------------------------------------------------------------------------------------
                                             CI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2016..........................................................                0.0004519                    3.477
2017..........................................................                0.0004371                    3.369
2018 to 2020..................................................                0.0004086                    3.143
----------------------------------------------------------------------------------------------------------------
                                             SI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2016..........................................................                0.0005277                    4.073
2017..........................................................                0.0005176                    3.983
2018 to 2020..................................................                0.0004951                    3.815
----------------------------------------------------------------------------------------------------------------
                                         Phase 2--Fixed Target Standards
----------------------------------------------------------------------------------------------------------------
                                             CI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2021..........................................................                0.0003988                    3.065
2022..........................................................                0.0003880                    2.986
2023..........................................................                0.0003792                    2.917
2024..........................................................                0.0003694                    2.839
2025..........................................................                0.0003605                    2.770
2026..........................................................                0.0003507                    2.701
2027 and later................................................                0.0003418                    2.633
----------------------------------------------------------------------------------------------------------------
                                             SI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2021..........................................................                0.0004827                    3.725
2022..........................................................                0.0004703                    3.623
2023..........................................................                0.0004591                    3.533
2024..........................................................                0.0004478                    3.443
2025..........................................................                0.0004366                    3.364
2026..........................................................                0.0004253                    3.274
2027 and later................................................                0.0004152                    3.196
----------------------------------------------------------------------------------------------------------------

    (3) Fleet average fuel consumption standard. (i) For the Phase 1
program, calculate each manufacturer's fleet average fuel consumption
standard for a conventional fleet and a combined advanced technology
fleet separately based on the subconfiguration target standards
specified in paragraph (a)(2) of this section, weighted to production
volumes and averaged using the following equation combining all the
applicable vehicles in a manufacturer's U.S.-directed fleet
(compression-ignition, spark-ignition and advanced technology vehicles)
for a given model year, rounded to the nearest 0.001 gallons per 100
miles:
[GRAPHIC] [TIFF OMITTED] TP13SE22.000

Where:

Subconfiguration Target Standardi = fuel consumption standard for
each group of vehicles with same payload, towing capacity and drive
configuration (gallons per 100 miles).
Volumei = production volume of each unique subconfiguration of a
model type based upon payload, towing capacity and drive
configuration.

    (A) A manufacturer may group together subconfigurations that have
the same test weight (ETW), GVWR, and GCWR. Calculate work factor and
target value assuming a curb weight equal to two times ETW minus GVWR.
    (B) A manufacturer may group together other subconfigurations if it
uses the lowest target value calculated for any of the
subconfigurations.
    (ii) For Phase 1, manufacturers must select an alternative for
subconfiguration target standards at the same time they submit the
model year 2016 pre-model year Report, specified in Sec.  535.8. Once
selected, the decision cannot be reversed and the manufacturer must
continue to comply with the same alternative for subsequent model
years.
    (4) Voluntary standards. (i) Manufacturers may choose voluntarily
to comply early with fuel consumption standards for model years 2013
through 2015, as determined in paragraphs (a)(4)(iii) and (iv) of this
section, for example, in order to begin accumulating credits through
over-compliance with the applicable standard. A manufacturer choosing
early compliance must comply with all the vehicles and engines it
manufactures in each regulatory category for a given model year.
    (ii) A manufacturer must declare its intent to voluntarily comply
with fuel consumption standards at the same time it submits a Pre-Model
Report, prior to the compliance model year beginning as specified in
Sec.  535.8; and, once selected, the decision cannot be reversed and
the manufacturer must continue to comply for each subsequent model year
for all the vehicles and engines it manufactures in each regulatory
category for a given model year.
    (iii) Calculate separate subconfiguration target standards for
compression-ignition and spark- ignition vehicles for model years 2013
through 2015 using the equation in paragraph (a)(2)(ii) of this
section, substituting the appropriate values for the coefficients in
the following table as appropriate:

                      Table 7--Coefficients for Voluntary Subconfiguration Target Standards
----------------------------------------------------------------------------------------------------------------
                         Model year(s)                                     c                        d
----------------------------------------------------------------------------------------------------------------
                                             CI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2013 and 14...................................................                0.0004695                    3.615
2015..........................................................                0.0004656                    3.595
----------------------------------------------------------------------------------------------------------------
                                             SI Vehicle Coefficients
----------------------------------------------------------------------------------------------------------------
2013 and 14...................................................                0.0005424                    4.175
2015..........................................................                0.0005390                    4.152
----------------------------------------------------------------------------------------------------------------

    (iv) Calculate the fleet average fuel consumption standards for
model years 2013 through 2015 using the equation in paragraph (a)(3) of
this section.
    (5) Exclusion of vehicles not certified as complete vehicles. The
vehicle standards in paragraph (a) of this section do not apply for
vehicles that are chassis-certified with respect to EPA's criteria
pollutant test procedure in 40 CFR part 86, subpart S. Any chassis-
certified vehicles must comply with the vehicle standards and
requirements of paragraph (b) of this section and the engine standards
of paragraph (d) of this section for engines used in these vehicles. A
vehicle manufacturer choosing to comply with this paragraph and that is
not the engine manufacturer is required to notify the engine
manufacturers that their engines are subject to paragraph (d) of this
section and that it intends to use their engines in excluded vehicles.
    (6) Optional certification under this section. Manufacturers may
certify certain complete or cab- complete vehicles to the fuel
consumption standards of this section. All vehicles optionally
certified under this paragraph (a)(6) are deemed to be subject to the
fuel consumption standards of this section given the following
conditions:
    (i) For fuel consumption compliance, manufacturers may certify any
complete or cab-complete spark-ignition vehicles above 14,000 pounds
GVWR and at or below 26,000 pounds GVWR to the fuel consumption
standards of this section.
    (ii) Manufacturers may apply the provisions of this section to cab-
complete vehicles based on a complete sister vehicle. In unusual
circumstances, manufacturers may ask the agencies to apply these
provisions to Class 2b or Class 3 incomplete vehicles that do not meet
the definition of cab-complete.
    (A) Except as specified in paragraph (a)(6)(iii) of this section,
for purposes of this section, a complete sister vehicle is a complete
vehicle of the same vehicle configuration as the cab- complete vehicle.
A manufacturer may not apply the provisions of this paragraph (a)(6) to
any vehicle configuration that has a four-wheel rear axle if the
complete sister vehicle has a two- wheel rear axle.
    (B) Calculate the target value for the fleet-average fuel
consumption standard under paragraph (a)(3) of this section based on
the work factor value that applies for the complete sister vehicle.
    (C) Test these cab-complete vehicles using the same equivalent test
weight and other dynamometer settings that apply for the complete
vehicle from which you used the work factor value (the complete sister
vehicle). For fuel consumption certification, manufacturers may submit
the test data from that complete sister vehicle instead of performing
the test on the cab- complete vehicle.
    (D) Manufacturers are not required to produce the complete sister
vehicle for sale to use the provisions of this paragraph (a)(6)(ii).
This means the complete sister vehicle may be a carryover vehicle from
a prior model year or a vehicle created solely for the purpose of
testing.
    (iii) For fuel consumption purposes, if a cab-complete vehicle is
not of the same vehicle configuration as a complete sister vehicle due
only to certain factors unrelated to coastdown performance,
manufacturers may use the road-load coefficients from the complete
sister vehicle for certification testing of the cab-complete vehicle,
but it may not use fuel consumption data from the complete sister
vehicle for certifying the cab-complete vehicle.

    (7) Loose engines. For model year 2023 and earlier spark-ignition
engines with identical hardware compared with engines used in vehicles
certified to the standards of this section, where such engines are sold
as loose engines or as engines installed in incomplete vehicles that
are not cab-complete vehicles. Manufacturers may certify such engines
to the standards of this section, subject to the following provisions:
    (i) For 2020 and earlier model years, the maximum allowable U.S.-
directed production volume of engines manufacturers may sell under this
paragraph (a)(7) in any given model year is ten percent of the total
U.S-directed production volume of engines of that design that the
manufacturer produces for heavy-duty applications for that model year,
including engines it produces for complete vehicles, cab-complete
vehicles, and other incomplete vehicles. The total number of engines a
manufacturer may certify under this paragraph (a)(7), of all engine
designs, may not exceed 15,000 in any model year. Engines produced in
excess of either of these limits are not covered by your certificate.
For example, a manufacturer produces 80,000 complete model year 2017
Class 2b pickup trucks with a certain engine and 10,000 incomplete
model year 2017 Class 3 vehicles with that same engine, and the
manufacturer did not apply the provisions of this paragraph (a)(7) to
any other engine designs, it may produce up to 10,000 engines of that
design for sale as loose engines under this paragraph (a)(7). If a
manufacturer produced 11,000 engines of that design for sale as loose
engines, the last 1,000 of them that it produced in that model year
2017 would be considered uncertified.
    (ii) For model years 2021 through 2023, the U.S.-directed
production volume of engines manufacturers sell under this paragraph
(a)(7) in any given model year may not exceed 10,000 units. This
paragraph (a)(7) does not apply for engines certified to the standards
of paragraph (d) of this section and 40 CFR 1036.108.
    (iii) Vehicles using engines certified under this paragraph (a)(7)
are subject to the fuel consumption and emission standards of paragraph
(b) of this section and 40 CFR 1037.105 and engine standards in 40 CFR
1036.150(j).
    (iv) For certification purposes, engines are deemed to have a fuel
consumption target values and test result equal to the fuel consumption
target value and test result for the complete vehicle in the applicable
test group with the highest equivalent test weight, except as specified
in paragraph (a)(7)(iv)(B) of this part. Manufacturers use these values
to calculate target values and the fleet- average fuel consumption
rate. Where there are multiple complete vehicles with the same highest
equivalent test weight, select the fuel consumption target value and
test result as follows:
    (A) If one or more of the fuel consumption test results exceed the
applicable target value, use the fuel consumption target value and test
result of the vehicle that exceeds its target value by the greatest
amount.
    (B) If none of the fuel consumption test results exceed the
applicable target value, select the highest target value and set the
test result equal to it. This means that the manufacturer may not
generate fuel consumption credits from vehicles certified under this
paragraph (a)(7).
    (8) Alternative fuel vehicle conversions. Alternative fuel vehicle
conversions may demonstrate compliance with the standards of this part
or other alternative compliance approaches allowed by EPA in 40 CFR
85.525.
    (9) Advanced, innovative and off-cycle technologies. For vehicles
subject to Phase 1 standards, manufacturers may generate separate
credit allowances for advanced and innovative technologies as specified
in Sec.  535.7(f)(1) and (2). For vehicles subject to Phase 2
standards, manufacturers may generate separate credits allowance for
off-cycle technologies in accordance with Sec.  535.7(f)(2). Separate
credit allowances for advanced technology vehicles cannot be generated;
instead manufacturers may use the credit multipliers specified in Sec.
535.7(f)(1)(iv) through model year 2026.
    (10) Useful life. The following useful life values apply for the
standards of this section:
    (i) 120,000 miles or 10 years, whichever comes first, for Class 2b
through Class 3 heavy-duty pickup trucks and vans certified to Phase 1
standards.
    (ii) 150,000 miles or 15 years, whichever comes first, for Class 2b
through Class 3 heavy-duty pickup trucks and vans certified to Phase 2
standards.
    (iii) For Phase 1 credits that you calculate based on a useful life
of 120,000 miles, multiply any banked credits that you carry forward
for use into the Phase 2 program by 1.25. For Phase 1 credit deficits
that you generate based on a useful life of 120,000 miles multiply the
credit deficit by 1.25 if offsetting the shortfall with Phase 2
credits.
    (11) Compliance with standards. A manufacturer complies with the
standards of this part as described in Sec.  535.10.
    (b) Heavy-duty vocational vehicles. Each manufacturer building
complete or incomplete heavy- duty vocational vehicles shall comply
with the fuel consumption standards in this paragraph (b) expressed in
gallons per 1000 ton-miles. Manufacturers must apply the fuel
consumption standards in this paragraph (b) to the same vehicles using
the same options used to comply with EPA in 40 CFR 1037.105. Engines
used in heavy-duty vocational vehicles shall comply with the standards
in paragraph (d) of this section. Each vehicle must be manufactured to
comply for its full useful life. Standards apply to the vehicle
subfamilies based upon the vehicle service classes within each of the
vocational vehicle regulatory subcategories in accordance with Sec.
535.4 and based upon the applicable modeling and testing specified in
Sec.  535.6. Determine the duty cycles that apply to vocational
vehicles according to 40 CFR 1037.140 and 1037.150(z).
    (1) Mandatory standards. Heavy-duty vocational vehicle subfamilies
produced for Phase 1 must comply with the fuel consumption standards in
paragraph (b)(3) of this section. For Phase 2, each vehicle
manufacturer of heavy-duty vocational vehicle subfamilies must comply
with the fuel consumption standards in paragraph (b)(4) of this
section.
    (i) For model years 2016 to 2020, the heavy-duty vocational vehicle
category is subdivided by GVWR into three regulatory subcategories as
defined in Sec.  535.4, each with its own assigned standard.
    (ii) For model years 2021 and later, the heavy-duty vocational
vehicle category is subdivided into 15 regulatory subcategories
depending upon whether vehicles are equipped with a compression or
spark-ignition engine, as defined in Sec.  535.4. Standards also differ
based upon vehicle service class and intended vehicle duty cycles. See
40 CFR 1037.140 and 1037.150(z).
    (iii) For purposes of certifying vehicles to fuel consumption
standards, manufacturers must divide their product lines in each
regulatory subcategory into vehicle families that have similar
emissions and fuel consumption features, as specified by EPA in 40 CFR
1037.230. These families will be subject to the applicable standards.
Each vehicle family is limited to a single model year.
    (2) Voluntary compliance. (i) For model years 2013 through 2015, a
manufacturer may choose voluntarily to comply early with the fuel
consumption standards provided in paragraph (b)(3)

of this section. For example, a manufacturer may choose to comply early
in order to begin accumulating credits through over-compliance with the
applicable standards. A manufacturer choosing early compliance must
comply with all the vehicles and engines it manufactures in each
regulatory category for a given model year.
    (ii) A manufacturer must declare its intent to voluntarily comply
with fuel consumption standards and identify its plans to comply before
it submits its first application for a certificate of conformity for
the respective model year as specified in Sec.  535.8; and, once
selected, the decision cannot be reversed and the manufacturer must
continue to comply for each subsequent model year for all the vehicles
and engines it manufactures in each regulatory category for a given
model year.
    (3) Regulatory subcategory standards for model years 2013 to 2020.
The mandatory and voluntary fuel consumption standards for heavy-duty
vocational vehicles are given in the following table:

                         Table 8--Phase 1 Vocational Vehicle Fuel Consumption Standards
                                          [Gallons per 1000 ton-miles]
----------------------------------------------------------------------------------------------------------------
       Regulatory subcategories        Vocational LHD Vehicles  Vocational MHD Vehicles  Vocational HHD Vehicles
----------------------------------------------------------------------------------------------------------------
                                  Model Years 2013 to 2016 Voluntary Standards
----------------------------------------------------------------------------------------------------------------