in the United States, as prescribed by CAA section 203(a).
Participation in some programs is voluntary; but once a manufacturer
has elected to participate, it must submit the required information.
     Estimated number of respondents: Approximately 77
heavy-duty vehicle manufacturers.
     Frequency of response: One-time burden associated with
reviewing the new requirements for all manufacturers; for EV
manufacturers, one-time burden associated with new battery health
monitor provisions, warranty reporting requirements, and associated
revisions to owners manuals
     Total estimated burden: 7,411 hours. Burden is defined
at 5 CFR 1320.03(b)
     Total estimated cost: $1.622 million; includes an
estimated $936,500 maintenance and operational costs.

    An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the Agency's need for this information, the
accuracy of the provided burden estimates and any suggested methods for
minimizing respondent burden to EPA using the docket identified at the
beginning of this rule. You may also send your ICR-related comments to
OMB's Office of Information and Regulatory Affairs using the interface
at www.reginfo.gov/public/do/PRAMain. Find this particular information
collection by selecting ``Currently under Review--Open''. Since OMB is
required to make a decision concerning the ICR between 30 and 60 days
after receipt, OMB must receive comments no later than June 26, 2023.
The EPA will respond to any ICR-related comments in the final rule.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. As
explained elsewhere in this preamble, EPA is proposing to exempt small
entities from the proposed revisions to EPA's Phase 2 GHG requirements
for MY 2027 and the proposed additional GHG requirements for MYs 2028
through 2032 and later. Small EV manufacturers would be subject to new
battery health monitor provisions and warranty provisions, which
include making associated revisions to owners manuals. There are 10
small companies that would be affected by the proposal. The estimated
burden is not expected to exceed 3 percent of annual revenue for any
small entity, and is expected to be between 1 and 3 percent of annual
revenue for only one company. We have therefore concluded that this
action will have minimal impact on small entities within the regulated
industries. More information concerning the small entities and our
decision is presented in Chapter 9 of the draft RIA.

D. Unfunded Mandates Reform Act (UMRA)

    This proposed rule contains no Federal mandates under UMRA, 2
U.S.C. 1531-1538, for State, local, or Tribal governments. The proposed
rule would impose no enforceable duty on any State, local or Tribal
government. This proposed rule would contain a Federal mandate under
UMRA that may result in expenditures of $100 million or more for the
private sector in any one year. Accordingly, the costs and benefits
associated with the proposed rule are discussed in Section VIII and in
the draft RIA, which are in the docket for this rule.
    This action is not subject to the requirements of section 203 of
UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments.

E. Executive Order 13132: Federalism

    The action we are proposing for HD Phase 3 CO2 emission
standards and related regulations does not have federalism
implications. The proposed HD Phase 3 CO2 emission standards
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.
    The action we are proposing with regard to preemption of State
control of air pollutant emissions from new locomotives and new engines
used in locomotives (described in Section X), however, does have
federalism implications because the proposed revisions to part 1074
involve existing regulations that preempt State law under CAA section
209(e)(1). This action proposes revisions to current regulatory
provisions in order to better align EPA's rules with CAA section
209(e)'s statutory requirements. Today's action proposes to remove
regulatory language that extended the preemption period beyond the
point at which locomotives and engines are new. In this rule, EPA
proposes to revise our locomotive preemption regulations to better
align with precise language Congress provided in section 209(e) and the
Congressional directive to EPA to implement the prohibition of state
regulation of new locomotives and new engines used in locomotives while
ensuring that states are not impeded from adopting programs as allowed
by the CAA to address the contribution of air pollutant emissions from
non-new locomotives and engines to their air quality issues. EPA
consulted with representatives of various State and local governments
in developing this proposed rule. We met with representatives from the
National Association of State Energy Officials, the National
Association of Clean Air Agencies, the Northeast States for Coordinated
Air Use Management, the Ozone Transport Commission, and the Association
of Air Pollution Control Agencies in a joint meeting on April 21, 2022.
We met with representatives from CARB periodically from September to
December 2022, and we met with representatives from the National
Association of Clean Air Agencies, the Northeast States for Coordinated
Air Use Management, and the Ozone Transport Commission in a joint
meeting on December 13, 2022. In the spirit of Executive Order 13132,
and consistent with EPA policy to promote communications between EPA
and State and local governments, EPA specifically solicits comment on
this proposed rule revision from State and local officials.

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

    This action does not have Tribal implications as specified in
Executive Order 13175. Thus, Executive Order 13175 does not apply to
this action.

This action does not have substantial direct effects on one or more
Indian tribes, on the relationship between the Federal Government and
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes. However, EPA plans to
continue engaging with Tribal stakeholders in the development of this
rulemaking by offering a Tribal workshop and offering government-to-
government consultation upon request.

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

    This action is subject to Executive Order 13045 because it is a
significant regulatory action under section 3(f)(1) of Executive Order
12866, and EPA believes that the environmental health risks or safety
risks of the pollutants addressed by this action may have a
disproportionate effect on children. The 2021 Policy on Children's
Health also applies to this action.\1039\ Accordingly, we have
evaluated the environmental health or safety effects of air pollutants
affected by the proposed program on children. The results of this
evaluation are described in Section VI of the preamble and Chapter 5 of
the DRIA. The protection offered by these standards may be especially
important for children because childhood represents a life stage
associated with increased susceptibility to air pollutant-related
health effects.
---------------------------------------------------------------------------

    \1039\ U.S. Environmental Protection Agency (2021). 2021 Policy
on Children's Health. Washington, DC. https://www.epa.gov/system/files/documents/2021-10/2021-policy-on-childrens-health.pdf.
---------------------------------------------------------------------------

    This proposed rule would reduce emissions of GHGs, which would
reduce the effects of climate change on children. GHGs contribute to
climate change and the GHG emissions reductions resulting from
implementation of this proposed rule would further improve children's
health. The assessment literature cited in EPA's 2009 and 2016
Endangerment Findings concluded that certain populations and life
stages, including children, the elderly, and the poor, are most
vulnerable to climate-related health effects. The assessment literature
since 2016 strengthens these conclusions by providing more detailed
findings regarding these groups' vulnerabilities and the projected
impacts they may experience. These assessments describe how children's
unique physiological and developmental factors contribute to making
them particularly vulnerable to climate change. Impacts to children are
expected from heat waves, air pollution, infectious and waterborne
illnesses, and mental health effects resulting from extreme weather
events. In addition, children are among those especially susceptible to
most allergic diseases, as well as health effects associated with heat
waves, storms, and floods. Additional health concerns may arise in low-
income households, especially those with children, if climate change
reduces food availability and increases prices, leading to food
insecurity within households. More detailed information on the impacts
of climate change to human health and welfare is provided in Section
VI.A of this preamble.
    Children make up a substantial fraction of the U.S. population, and
often have unique factors that contribute to their increased risk of
experiencing a health effect from exposures to ambient air pollutants
because of their continuous growth and development. Children are more
susceptible than adults to many air pollutants because they have (1) a
developing respiratory system, (2) increased ventilation rates relative
to body mass compared with adults, (3) an increased proportion of oral
breathing, particularly in boys, relative to adults, and (4) behaviors
that increase chances for exposure. Even before birth, the developing
fetus may be exposed to air pollutants through the mother that affect
development and permanently harm the individual when the mother is
exposed.
    In addition to reducing GHGs, this proposed rule would also reduce
onroad emissions of criteria pollutants and air toxics. Section V of
this preamble presents the estimated onroad emissions reductions from
the proposed rule. Certain motor vehicle emissions present greater
risks to children. Early lifestages (e.g., children) are thought to be
more susceptible to tumor development than adults when exposed to
carcinogenic chemicals that act through a mutagenic mode of
action.\1040\ Exposure at a young age to these carcinogens could lead
to a higher risk of developing cancer later in life. Chapter 5.2.8 of
the DRIA describes a systematic review and meta-analysis conducted by
the U.S. Centers for Disease Control and Prevention that reported a
positive association between proximity to traffic and the risk of
leukemia in children.
---------------------------------------------------------------------------

    \1040\ U.S. Environmental Protection Agency. (2005).
Supplemental guidance for assessing susceptibility from early-life
exposure to carcinogens. Washington, DC: Risk Assessment Forum. EPA/
630/R-03/003F. https://www3.epa.gov/airtoxics/childrens_supplement_final.pdf.
---------------------------------------------------------------------------

    The adverse effects of individual air pollutants may be more severe
for children, particularly the youngest age groups, than adults. As
described in Section VI.B of this preamble and Chapter 5 of the DRIA,
the Integrated Science Assessments for a number of pollutants affected
by this rule, including those for SO2, NO2, PM, ozone and
CO, describe children as a group with greater susceptibility. Also,
Section VI.B of this preamble and Chapter 5 of the DRIA discuss a
number of childhood health outcomes associated with proximity to
roadways, including evidence for exacerbation of asthma symptoms and
suggestive evidence for new onset asthma.
    There is substantial evidence that people who live or attend school
near major roadways are more likely to be people of color, Hispanic
ethnicity, and/or low socioeconomic status. Within these highly exposed
groups, children's exposure and susceptibility to health effects is
greater than adults due to school-related and seasonal activities,
behavior, and physiological factors.
    Children are not expected to experience greater ambient
concentrations of air pollutants than the general population. However,
because of their greater susceptibility to air pollution, including the
impacts of a changing climate, and their increased time spent outdoors,
it is likely that the emissions reductions associated with the proposed
standards would have particular benefits for children's health.

H. 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. EPA has outlined the energy effects in
Section VI of this preamble and Chapter 5 of the draft RIA, which is
available in the docket for this action and is briefly summarized here.
    This action proposes to reduce CO2 emissions from heavy-
duty vehicles under revised GHG standards, which would result in
significant reductions in the consumption of petroleum, would achieve
energy security benefits, and would have no adverse energy effects.
Because the GHG emission standards result in fuel savings, this rule
encourages more efficient use of fuels. Section VI.F of this preamble
describes our projected fuel savings due to the proposed standards.

I. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR
Part 51

    This rulemaking involves technical standards. Except for the
standards discussed in this Section XI.I, the standards included in the
regulatory text as incorporated by reference were all previously
approved for IBR and no change is included in this action.
    In accordance with the requirements of 1 CFR 51.5, we are proposing
to incorporate by reference the use of standards and test methods from
the United Nations. The referenced standards and test methods may be
obtained from the UN Economic Commission for Europe, Information
Service at Palais des Nations, CH-1211 Geneva 10, Switzerland;
[email protected]; www.unece.org. We are incorporating by reference the
following UN Economic Commission for Europe document:

------------------------------------------------------------------------
     Standard or test method          Regulation            Summary
------------------------------------------------------------------------
Addendum 22: United Nations       40 CFR 1037.115     GTR 22 establishes
 Global Technical Regulation No.   and 1037.810.       design protocols
 22, United Nations Global                             and procedures
 Technical Regulation on In-                           for measuring
 vehicle Battery Durability for                        durability and
 Electrified Vehicles, Adopted                         performance for
 April 14, 2022.                                       batteries used
                                                       with electric
                                                       vehicles and plug-
                                                       in hybrid-
                                                       electric
                                                       vehicles.
------------------------------------------------------------------------

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

    Executive Order 12898 (59 FR 7629, February 16, 1994) directs
Federal agencies, to the greatest extent practicable and permitted by
law, to make environmental justice part of their mission by identifying
and addressing, as appropriate, disproportionately high and adverse
human health or environmental effects of their programs, policies, and
activities on minority populations (people of color and/or indigenous
peoples) and low-income populations.
    EPA believes that the human health or environmental conditions that
exist prior to this action result in or have the potential to result in
disproportionate and adverse human health or environmental effects on
people of color, low-income populations and/or indigenous peoples. EPA
provides a summary of the evidence for potentially disproportionate and
adverse effects among people of color and low-income populations in
Section VI.D of the preamble for this rule.
    EPA believes that this action is likely to reduce existing
disproportionate and adverse effects on people of color, low-income
populations and/or indigenous peoples.
    Section VI.D.1 discusses the environmental justice issues
associated with climate change. People of color, low-income populations
and/or indigenous peoples may be especially vulnerable to the impacts
of climate change. The GHG emission reductions from this proposal would
contribute to efforts to reduce the probability of severe impacts
related to climate change.
    In addition to reducing GHGs, this proposed rule would also reduce
onroad emissions of criteria pollutants and air toxics. Section V of
this preamble presents the estimated impacts from the proposed rule on
onroad and EGU emissions. These non-GHG emission reductions from
vehicles would improve air quality for the people who reside in close
proximity to major roadways and who are disproportionately represented
by people of color and people with low income, as described in Section
VI.D.2 of this preamble. We expect that increases in criteria and toxic
pollutant emissions from EGUs and reductions in petroleum-sector
emissions could lead to changes in exposure to these pollutants for
people living in the communities near these facilities. Analyses of
communities in close proximity to these sources (such as EGUs and
refineries) have found that a higher percentage of communities of color
and low-income communities live near these sources when compared to
national averages.
    EPA is additionally identifying and addressing environmental
justice concerns by providing fair treatment and meaningful involvement
with Environment Justice groups in developing this proposed action and
soliciting input for this notice of proposed rulemaking.
    The information supporting this Executive Order review is contained
in Section VI.D of the preamble for this rule, and all supporting
documents have been placed in the public docket for this action.

XII. Statutory Authority and Legal Provisions

    Statutory authority for the proposed GHG standards is found in CAA
section 202(a)(1)-(2), 42 U.S.C. 7521 (a)(1)-(2), which requires EPA to
establish standards applicable to emissions of air pollutants from new
motor vehicles and engines which cause or contribute to air pollution
which may reasonably be anticipated to endanger public health or
welfare. Statutory authority for this proposed rule overall is found at
42 U.S.C. 7401-7675.

List of Subjects

40 CFR Part 1036

    Environmental protection, Administrative practice and procedure,
Air pollution control, Confidential business information, Greenhouse
gases, Incorporation by reference, Labeling, Motor vehicle pollution,
Reporting and recordkeeping requirements, Warranties.

40 CFR Part 1037

    Environmental protection, Administrative practice and procedure,
Air pollution control, Confidential business information, Incorporation
by reference, Labeling, Motor vehicle pollution, Reporting and
recordkeeping requirements, Warranties.

40 CFR Part 1054

    Environmental protection, Administrative practice and procedure,
Air pollution control, Confidential business information, Imports,
Labeling, Penalties, Reporting and recordkeeping requirements,
Warranties.

40 CFR Part 1065

    Environmental protection, Administrative practice and procedure,
Air pollution control, Incorporation by reference, Reporting and
recordkeeping requirements, Research.

40 CFR Part 1074

    Environmental protection, Administrative practice and procedure,
Air pollution control, Locomotives, Nonroad engines, Scope of
preemption.

Michael S. Regan,
Administrator.
    For the reasons set out in the preamble, we are proposing to amend
title 40, chapter I of the Code of Federal Regulations as set forth
below.

PART 1036--CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVY-DUTY
HIGHWAY ENGINES

0
1. The authority citation for part 1036 continues to read as follows:

    Authority: 42 U.S.C. 7401-7671q.

0
2. Amend Sec.  1036.101 by revising the introductory text and paragraph
(a)(1) to read as follows:

Sec.  1036.101  Overview of exhaust emission standards.

    This part contains standards and other regulations applicable to
the emission of the air pollutant defined as the aggregate group of six
greenhouse gases: carbon dioxide, nitrous oxide, methane,
hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.
    (a) * * *
    (1) Criteria pollutant standards for NOX, HC, PM, and CO
apply as described in Sec.  1036.104. These pollutants are sometimes
described collectively as ``criteria pollutants'' because they are
either criteria pollutants under the Clean Air Act or precursors to the
criteria pollutants ozone and PM.
* * * * *

Sec.  1036.104--  [Amended]

0
3. Amend Sec.  1036.104 by removing paragraph (c)(2)(iii).
0
4. Amend Sec.  1036.108 by revising paragraphs (a)(1)(iii) introductory
text and (e) to read as follows:

Sec.  1036.108  Greenhouse gas emission standards--CO2,
CH4, and N2O.

* * * * *
    (a) * * *
    (1) * * *
    (iii) The following Phase 2 and Phase 3 CO2 standards
apply for compression-ignition engines and all Heavy HDE (in g/
hp[middot]hr):
* * * * *
    (e) Applicability for testing. The emission standards in this
subpart apply as specified in this paragraph (e) to all duty-cycle
testing (according to the applicable test cycles) of testable
configurations, including certification, selective enforcement audits,
and in-use testing. The CO2 FCLs serve as the CO2
emission standards for the engine family with respect to certification
and confirmatory testing instead of the standards specified in
paragraph (a)(1) of this section. The FELs serve as the emission
standards for the engine family with respect to all other duty-cycle
testing. See Sec. Sec.  1036.235 and 1036.241 to determine which engine
configurations within the engine family are subject to testing. Note
that engine fuel maps and powertrain test results also serve as
standards as described in Sec. Sec.  1036.535, 1036.540, 1036.545, and
1036.630.
0
5. Amend Sec.  1036.110 by revising paragraphs (b)(6), (b)(9)
introductory text, (b)(11)(ii) and (c)(1) to read as follows:

Sec.  1036.110  Diagnostic controls.

* * * * *
    (b) * * *
    (6) The provisions related to verification of in-use compliance in
13 CCR 1971.1(l)(4) do not apply. The provisions related to
manufacturer self-testing in 13 CCR 1971.5(c) also do not apply.
* * * * *
    (9) Design compression-ignition engines to make the following
additional data-stream signals available on demand with a generic scan
tool according to 13 CCR 1971.1(h)(4.2), if the engine is so equipped
with the relevant components and OBD monitoring is required for those
components:
* * * * *
    (11) * * *
    (ii) Send us results from any testing you performed for certifying
engine families (including equivalent engine families) with the
California Air Resources Board, including the results of any testing
performed under 13 CCR 1971.1(l) for verification of in-use compliance
and 13 CCR 1971.5(c) for manufacturer self-testing within the deadlines
set out in 13 CCR 1971.1 and 1971.5.
* * * * *
    (c) * * *
    (1) For inducements specified in Sec.  1036.111 and any other AECD
that derates engine output related to SCR or DPF systems, indicate the
fault code for the detected problem, a description of the fault code,
and the current speed restriction. For inducement faults under Sec.
1036.111, identify whether the fault condition is for DEF level, DEF
quality, or tampering; for other faults, identify whether the fault
condition is related to SCR or DPF systems. If there are additional
derate stages, also indicate the next speed restriction and the time
remaining until starting the next restriction. If the derate involves
something other than restricting vehicle speed, such as a torque
derate, adjust the information to correctly identify any current and
pending restrictions.
* * * * *
0
6. Amend Sec.  1036.111 by revising paragraphs (a)(2), (b) introductory
text, (d), and (e) to read as follows:

Sec.  1036.111  Inducements related to SCR.

* * * * *
    (a) * * *
    (2) The provisions of this section apply differently based on an
individual vehicle's speed history. A vehicle's speed category is based
on the OBD system's recorded value for average speed for the preceding
30 hours of non-idle engine operation. The vehicle speed category
applies at the point that the engine first detects an inducement
triggering condition identified under paragraph (b) of this section and
continues to apply until the inducement triggering condition is fully
resolved as specified in paragraph (e) of this section. Non-idle engine
operation includes all operating conditions except those that qualify
as idle based on OBD system controls as specified in 13 CCR
1971.1(h)(5.4.10). Apply speed derates based on the following
categories:

   Table 1 to Paragraph (a)(2) of Sec.   1036.111--Vehicle Categories
------------------------------------------------------------------------
           Vehicle category \a\                 Average speed (mi/hr)
------------------------------------------------------------------------
Low-speed.................................  speed <15.
Medium-speed..............................  15< speed <25.
High-speed................................  speed >25.
------------------------------------------------------------------------
\a\ A vehicle is presumed to be a high-speed vehicle if it has not yet
  logged 30 hours of non-idle operation.

* * * * *
    (b) Inducement triggering conditions. Create derate strategies that
monitor for and trigger an inducement based on the following
conditions:
* * * * *
    (d) Derate schedule. Engines must follow the derate schedule
described in this paragraph (d) if the engine detects an inducement
triggering condition identified in paragraph (b) of this section. The
derate takes the form of a maximum drive speed for the vehicle. This
maximum drive speed decreases over time based on hours of non-idle
engine operation without regard to engine starting.
    (1) Apply speed-limiting derates according to the following
schedule:

  Table 2 to Paragraph (d)(1) of Sec.   1036.111--Derate Schedule for Detected Inducement Triggering Conditions
                                                       \a\
----------------------------------------------------------------------------------------------------------------
               High-speed vehicles                     Medium-speed vehicles            Low-speed vehicles
----------------------------------------------------------------------------------------------------------------
                                                   Hours of non-                   Hours of non-
    Hours of non-idle engine       Maximum speed    idle engine    Maximum speed    idle engine    Maximum speed
            operation                 (mi/hr)        operation        (mi/hr)        operation        (mi/hr)
----------------------------------------------------------------------------------------------------------------
0...............................              65               0              55               0              45
6...............................              60               6              50               5              40
12..............................              55              12              45              10              35
20..............................              50              45              40              30              25
86..............................              45              70              35  ..............  ..............
119.............................              40              90              25  ..............  ..............
144.............................              35  ..............  ..............  ..............  ..............
164.............................              25  ..............  ..............  ..............  ..............
----------------------------------------------------------------------------------------------------------------
 \a\Hours start counting when the engine detects an inducement triggering condition specified in paragraph (b)
  of this section. For DEF supply, you may program the engine to reset the timer to three hours when the engine
  detects an empty DEF tank.

    (2) You may design and produce engines that will be installed in
motorcoaches with an alternative derate schedule that starts with a 65
mi/hr derate when an inducement triggering condition is first detected,
steps down to 50 mi/hr after 80 hours, and concludes with a final
derate speed of 25 mi/hr after 180 hours of non-idle operation.
    (e) Deactivating derates. Program the engine to deactivate derates
as follows:
    (1) Evaluate whether the detected inducement triggering condition
continues to apply. Deactivate derates if the engine confirms that the
detected inducement triggering condition is resolved.
    (2) Allow a generic scan tool to deactivate inducement triggering
codes while the vehicle is not in motion.
    (3) Treat any detected inducement triggering condition that recurs
within 40 hours of engine operation as the same detected inducement
triggering condition, which would restart the derate at the same point
in the derate schedule that the system last deactivated the derate.
0
7. Amend Sec.  1036.120 by revising paragraph (c) to read as follows:

Sec.  1036.120  Emission-related warranty requirements.

* * * * *
    (c) Components covered. The emission-related warranty covers all
components listed in 40 CFR part 1068, appendix A, and components from
any other system you develop to control emissions. Note that this
includes hybrid system components when a manufacturer's certified
configuration includes hybrid system components. The emission-related
warranty covers any components, regardless of the company that produced
them, that are the original components or the same design as components
from the certified configuration.
* * * * *
0
8. Amend Sec.  1036.125 by revising paragraph (h)(8)(iii) to read as
follows:

Sec.  1036.125  Maintenance instructions and allowable maintenance.

* * * * *
    (h) * * *
    (8) * * *
    (iii) A description of the three types of SCR-related derates (DEF
level, DEF quality and tampering) and that further information on the
inducement cause (e.g., trouble codes) is available using the OBD
system.
* * * * *
0
9. Amend Sec.  1036.150 by:
0
a. Revising paragraph (d);
0
b. Adding paragraph (f);
0
c. Revising paragraphs (j), and (k); and
0
d. Adding paragraph (aa).

    The additions and revisions read as follows:

Sec.  1036.150  Interim provisions.

* * * * *
    (d) Small manufacturers. The greenhouse gas standards of this part
apply on a delayed schedule for manufacturers meeting the small
business criteria specified in 13 CFR 121.201. Apply the small business
criteria for NAICS code 336310 for engine manufacturers with respect to
gasoline-fueled engines and 333618 for engine manufacturers with
respect to other engines; the employee limits apply to the total number
employees together for affiliated companies. Qualifying small
manufacturers are not subject to the greenhouse gas emission standards
in Sec.  1036.108 for engines with a date of manufacture on or after
November 14, 2011 but before January 1, 2022. In addition, qualifying
small manufacturers producing engines that run on any fuel other than
gasoline, E85, or diesel fuel may delay complying with every later
greenhouse gas standard under this part by one model year; however,
small manufacturers may generate emission credits only by certifying
all their engine families within a given averaging set to standards
that apply for the current model year. Note that engines not yet
subject to standards must nevertheless supply fuel maps to vehicle
manufacturers as described in paragraph (n) of this section. Note also
that engines produced by small manufacturers are subject to criteria
pollutant standards.
    162 HEI Panel on the Health Effects of Long-Term Exposure to
Traffic-Related Air Pollution (2022) Systematic review and meta-
analysis of selected health effects of long-term exposure to traffic-
related air pollution. Health Effects Institute Special Report 23.
[Online at https://www.healtheffects.org/publication/systematic-review-and-meta-analysis-selected-health-effects-long-term-exposure-traffic]
This more recent review focused on health outcomes related to birth
effects, respiratory effects, cardiometabolic effects, and mortality.
* * * * *
    (f) Testing exemption for qualifying engines. Tailpipe
CO2, CH4, HC, and CO emissions from engines
fueled with neat hydrogen are deemed to be zero. No fuel mapping, and
no testing for CO2, CH4, HC, or CO is required
under this part for these engines.
* * * * *
    (j) Alternate standards under 40 CFR part 86. This paragraph (j)
describes alternate emission standards that apply for model year 2023
and earlier loose engines certified under 40 CFR 86.1819-14(k)(8). The
standards of Sec.  1036.108 do not apply for these engines. The
standards in this paragraph (j) apply for emissions measured with the
engine installed in a complete vehicle

consistent with the provisions of 40 CFR 86.1819-14(k)(8)(vi). The only
requirements of this part that apply to these engines are those in this
paragraph (j), Sec. Sec.  1036.115 through 1036.135, 1036.535, and
1036.540.
    (k) Limited production volume allowance under ABT. You may produce
a limited number of Heavy HDE that continue to meet the standards that
applied under 40 CFR 86.007-11 in model years 2027 through 2029. The
maximum number of engines you may produce under this limited production
allowance is 5 percent of the annual average of your actual production
volume of Heavy HDE in model years 2023-2025 for calculating emission
credits under Sec.  1036.705. Engine certification under this paragraph
(k) is subject to the following conditions and requirements:
* * * * *
    (aa) Correcting credit calculations. If you notify us by October 1,
2024 that errors mistakenly decreased your balance of emission credits
for 2020 or any earlier model years, you may correct the errors and
recalculate the balance of emission credits after applying a 10 percent
discount to the credit correction.
0
10. Amend Sec.  1036.205 by revising paragraph (v) to read as follows:

Sec.  1036.205  Requirements for an application for certification.

* * * * *
    (v) Include good-faith estimates of U.S.-directed production
volumes. Include a justification for the estimated production volumes
if they are substantially different than actual production volumes in
earlier years for similar models.
* * * * *
0
11. Amend Sec.  1036.240 by revising paragraph (c)(3) to read as
follows:

Sec.  1036.240  Demonstrating compliance with criteria pollutant
emission standards.

* * * * *
    (c) * * *
    (3) Sawtooth and other nonlinear deterioration patterns. The
deterioration factors described in paragraphs (c)(1) and (2) of this
section assume that the highest useful life emissions occur either at
the end of useful life or at the low-hour test point. The provisions of
this paragraph (c)(3) apply where good engineering judgment indicates
that the highest useful life emissions will occur between these two
points. For example, emissions may increase with service accumulation
until a certain maintenance step is performed, then return to the low-
hour emission levels and begin increasing again. Such a pattern may
occur with battery-based hybrid engines or hybrid powertrains. Base
deterioration factors for engines with such emission patterns on the
difference between (or ratio of) the point at which the highest
emissions occur and the low-hour test point. Note that this applies for
maintenance-related deterioration only where we allow such critical
emission-related maintenance.
* * * * *
0
12. Amend Sec.  1036.241 by revising paragraph (c)(3) to read as
follows:

Sec.  1036.241  Demonstrating compliance with greenhouse gas emission
standards.

* * * * *
    (c) * * *
    (3) Sawtooth and other nonlinear deterioration patterns. The
deterioration factors described in paragraphs (c)(1) and (2) of this
section assume that the highest useful life emissions occur either at
the end of useful life or at the low-hour test point. The provisions of
this paragraph (c)(3) apply where good engineering judgment indicates
that the highest useful life emissions will occur between these two
points. For example, emissions may increase with service accumulation
until a certain maintenance step is performed, then return to the low-
hour emission levels and begin increasing again. Such a pattern may
occur with battery-based hybrid engines or hybrid powertrains. Base
deterioration factors for engines with such emission patterns on the
difference between (or ratio of) the point at which the highest
emissions occur and the low-hour test point. Note that this applies for
maintenance-related deterioration only where we allow such critical
emission-related maintenance.
* * * * *
0
13. Amend Sec.  1036.245 by revising paragraphs (c)(3) introductory
text and (c)(3)(ii) introductory text to read as follows:

Sec.  1036.245  Deterioration factors for exhaust emission standards.

* * * * *
    (c) * * *
    (3) Perform service accumulation in the laboratory by operating the
engine or hybrid powertrain repeatedly over one of the following test
sequences, or a different test sequence that we approve in advance:
* * * * *
    (ii) Duty-cycle sequence 2 is based on operating over the LLC and
the vehicle-based duty cycles from 40 CFR part 1037. Select the vehicle
subcategory and vehicle configuration from Sec.  1036.540 or Sec.
1036.545 with the highest reference cycle work for each vehicle-based
duty cycle. Operate the engine as follows for duty-cycle sequence 2:
* * * * *
0
14. Amend Sec.  1036.250 by revising paragraph (a) to read as follows:

Sec.  1036.250  Reporting and recordkeeping for certification.

    (a) By September 30 following the end of the model year, send the
Designated Compliance Officer a report including the total U.S.-
directed production volume of engines you produced in each engine
family during the model year (based on information available at the
time of the report). Report the production by serial number and engine
configuration. You may combine this report with reports required under
subpart H of this part. We may waive the reporting requirements of this
paragraph (a) for small manufacturers.
* * * * *
0
15. Amend Sec.  1036.301 by revising paragraph (c) to read as follows:

Sec.  1036.301  Measurements related to GEM inputs in a selective
enforcement audit.

* * * * *
    (c) If your certification includes powertrain testing as specified
in 40 CFR 1036.630, these selective enforcement audit provisions apply
with respect to powertrain test results as specified in 40 CFR part
1037, subpart D, and Sec.  1036.545. We may allow manufacturers to
instead perform the engine-based testing to simulate the powertrain
test as specified in 40 CFR 1037.551.
* * * * *
0
16. Amend Sec.  1036.405 by revising paragraphs (a)(1), (a)(3) and (d)
to read as follows:

Sec.  1036.405  Overview of the manufacturer-run field-testing program.

    (a) * * *
    (1) We may select up to 25 percent of your engine families in any
calendar year, calculated by dividing the number of engine families you
certified in the model year corresponding to the calendar year by four
and rounding to the nearest whole number. We will consider only engine
families with annual U.S.-directed production volumes above 1,500 units
in calculating the number of engine families subject to testing each
calendar year under the annual 25 percent engine family limit. If you
have only three or fewer families that each exceed an annual U.S.-
directed production volume of 1,500 units, we may select one engine
family per calendar year for testing.
* * * * *
    (3) We will not select engine families for testing under this
subpart from a

given model year if your total U.S.-directed production volume was less
than 100 engines.
* * * * *
    (d) You must complete all the required testing and reporting under
this subpart (for all ten test engines, if applicable), within 18
months after we direct you to test a particular engine family. We will
typically select engine families for testing and notify you in writing
by June 30 of the applicable calendar year. If you request it, we may
allow additional time to send us this information.
* * * * *
0
17. Amend Sec.  1036.420 by revising paragraph (a) to read as follows:

Sec.  1036.420  Pass criteria for individual engines.

* * * * *
    (a) Determine the emission standard for each regulated pollutant
for each bin by adding the following accuracy margins for PEMS to the
off-cycle standards in Sec.  1036.104(a)(3):

                Table 1 to Paragraph (a) of Sec.   1036.420--Accuracy Margins for In-Use Testing
----------------------------------------------------------------------------------------------------------------
                                          NOX                 HC                  PM                  CO
----------------------------------------------------------------------------------------------------------------
Bin 1...........................  0.4 g/hr..........
Bin 2...........................  5 mg/hp[middot]hr.  10 mg/hp[middot]hr  6 mg/hp[middot]hr.  0.25 g/
                                                                                hp[middot]hr.
----------------------------------------------------------------------------------------------------------------

* * * * *
0
18. Amend Sec.  1036.501 by adding paragraph (g) to read as follows:

Sec.  1036.501  General testing provisions.

* * * * *
    (g) For testing engines that use regenerative braking through the
crankshaft to only power an electric heater for aftertreatment devices,
you may use the fuel mapping procedure in Sec.  1036.505(b)(1) or (2)
and the nonhybrid engine testing procedures in Sec. Sec.  1036.510,
1036.512, and 1036.514, as long as the recovered energy is less than 10
percent of the total positive work for each applicable transient duty
cycle. Otherwise, use powertrain testing procedures specified for
hybrid engines or hybrid powertrains to create fuel maps and measure
emissions. For engines that power an electric heater with a battery,
you must meet the requirements related to charge-sustaining operation
as described in 40 CFR 1066.501.
0
19. Amend Sec.  1036.505 by revising paragraphs (a), (b) introductory
text, and (b)(3) and (4) to read as follows:

Sec.  1036.505  Engine data and information to support vehicle
certification.

* * * * *
    (a) Identify engine make, model, fuel type, combustion type, engine
family name, calibration identification, and engine displacement. Also
identify whether the engines meet CO2 standards for
tractors, vocational vehicles, or both. When certifying vehicles with
GEM, for any fuel type not identified in Table 1 of Sec.  1036.550,
select fuel type as diesel fuel for engines subject to compression-
ignition standards, and select fuel type as gasoline for engines
subject to spark-ignition standards.
    (b) This paragraph (b) describes four different methods to generate
engine fuel maps. For engines without hybrid components and for mild
hybrid engines where you do not include hybrid components in the test,
generate fuel maps using either paragraph (b)(1) or (2) of this
section. For other hybrid engines, generate fuel maps using paragraph
(b)(3) of this section. For hybrid powertrains and nonhybrid
powertrains and for vehicles where the transmission is not automatic,
automated manual, manual, or dual-clutch, generate fuel maps using
paragraph (b)(4) of this section.
* * * * *
    (3) Determine fuel consumption at idle as described in Sec.
1036.535(c) and (d) and determine cycle-average engine fuel maps as
described in Sec.  1036.545, including cycle-average engine fuel maps
for highway cruise cycles. Set up the test to apply accessory load for
all operation by primary intended service class as described in the
following table:

     Table 1 to Paragraph (b)(3) of Sec.   1036.505--Accessory Load
------------------------------------------------------------------------
                                                               Power
                                                           representing
             Primary intended service class               accessory load
                                                               (kW)
------------------------------------------------------------------------
Light HDV...............................................             1.5
Medium HDV..............................................             2.5
Heavy HDV...............................................             3.5
------------------------------------------------------------------------

    (4) Generate powertrain fuel maps as described in Sec.  1036.545
instead of fuel mapping under Sec.  1036.535 or Sec.  1036.540. Note
that the option in Sec.  1036.545(b)(2) is allowed only for hybrid
engine testing. Disable stop-start systems and automatic engine
shutdown systems when conducting powertrain fuel map testing using
Sec.  1036.545.
* * * * *
0
20. Amend Sec.  1036.510 by:
0
a. Revising paragraphs (b)(2) introductory text, (b)(2)(vii), and
(b)(2)(viii);
0
b. Removing paragraph (b)(2)(ix);
0
c. Revising paragraphs (c)(2)(i) introductory text, (d) introductory
text, and (d)(1) and (2)(ii);
0
d. Removing the period in the heading in Figure 1 to paragraph (d)(4);
and
0
e. Revising paragraphs (e), (f), and (g).

    The revisions read as follows:

Sec.  1036.510  Supplemental Emission Test.

* * * * *
    (b) * * *
    (2) Test hybrid engines and hybrid powertrains as described in
Sec.  1036.545, except as specified in this paragraph (b)(2). Do not
compensate the duty cycle for the distance driven as described in Sec.
1036.545(g)(4). For hybrid engines, select the transmission from Table
1 of Sec.  1036.540, substituting ``engine'' for ``vehicle'' and
``highway cruise cycle'' for ``SET''. Disregard duty cycles in Sec.
1036.545(j). For cycles that begin with idle, leave the transmission in
neutral or park for the full initial idle segment. Place the
transmission into drive no earlier than 5 seconds before the first
nonzero vehicle speed setpoint. For SET testing only, place the
transmission into park or neutral when the cycle reaches the final idle
segment. Use the following vehicle parameters instead of those in Sec.
1036.545 to define the vehicle model in Sec.  1036.545(a)(3):
* * * * *
    (vii) Select a combination of drive axle ratio, ka, and a tire
radius, r, that represents the worst-case combination of final gear
ratio, drive axle ratio, and tire size for CO2 expected for
vehicles in which the hybrid engine or hybrid powertrain will be
installed. This is typically the highest axle ratio and smallest tire
radius. In selecting a drive axle ratio and tire radius, if
representative, ensure that the maximum vehicle speed is no less than
60 mi/hr. Manufacturers may request preliminary approval for selected
drive axle ratio and tire radius consistent with the provisions of
Sec.  1036.210. If the hybrid engine or hybrid powertrain is used
exclusively in vehicles which are not capable of reaching 60 mi/hr,
follow the provisions of 40 CFR 1066.425(b)(5).

Note for hybrid engines the final gear ratio can change depending on
the duty-cycle, which will change the selection of the drive axle ratio
and tire size. For example, Sec.  1036.520 prescribes a different top
gear ratio than paragraph (b)(2) of this section.
    (viii) If you are certifying a hybrid engine, use a default
transmission efficiency of 0.95 and create the vehicle model along with
its default transmission shift strategy as described in Sec.
1036.545(a)(3)(ii). Use the transmission parameters defined in Table 1
of Sec.  1036.540 to determine transmission type and gear ratio. For
Light HDV and Medium HDV, use the Light HDV and Medium HDV parameters
for FTP, LLC, and SET duty cycles. For Tractors and Heavy HDVs, use the
Tractor and Heavy HDV transient cycle parameters for the FTP and LLC
duty cycles and the Tractor and Heavy HDV highway cruise cycle
parameters for the SET duty cycle.
    (c) * * *
    (2) * * *
    (i) Determine road grade at each point based on the continuous
rated power of the hybrid powertrain, Pcontrated, in kW
determined in Sec.  1036.520, the vehicle speed (A, B, or C) in mi/hr
for a given SET mode, vref[speed], and the specified road-
grade coefficients using the following equation:
* * * * *
    (d) Determine criteria pollutant emissions for plug-in hybrid
engines and plug-in hybrid powertrains as follows:
    (1) Precondition the engine or powertrain in charge-sustaining
mode. Perform testing as described in this section for hybrid engines
or hybrid powertrains in charge-sustaining mode.
    (2) * * *
    (ii) Operate the engine or powertrain continuously over repeated
SET duty cycles until you reach the end-of-test criterion defined in 40
CFR 1066.501(a)(3).
* * * * *
    (e) Determine greenhouse gas pollutant emissions for plug-in hybrid
engines and plug-in hybrid powertrains using the emissions results for
all the SET test intervals for both charge-depleting and charge-
sustaining operation from paragraph (d)(2) of this section. Calculate
the utility factor-weighted composite mass of emissions from the
charge-depleting and charge-sustaining test results,
eUF[emission]comp, using the following equation:
[GRAPHIC] [TIFF OMITTED] TP27AP23.032

Where:

i = an indexing variable that represents one test interval.
N = total number of charge-depleting test intervals.
e[emission][int]CDi = total mass of emissions in the
charge-depleting portion of the test for each test interval, i,
starting from i = 1, including the test interval(s) from the
transition phase.
UFDCDi = utility factor fraction at distance
DCDi from Eq. 1036.510-11, as determined by interpolating
the approved utility factor curve for each test interval, i,
starting from i = 1. Let UFDCD0 = 0.
j = an indexing variable that represents one test interval.
M = total number of charge-sustaining test intervals.
e[emission][int]CSj = total mass of emissions in the
charge-sustaining portion of the test for each test interval, j,
starting from j = 1.
UFRCD = utility factor fraction at the full charge-
depleting distance, RCD, as determined by interpolating the approved
utility factor curve. RCD is the cumulative distance driven over N
charge-depleting test intervals.
[GRAPHIC] [TIFF OMITTED] TP27AP23.033

Where:

k = an indexing variable that represents one recorded velocity
value.
Q = total number of measurements over the test interval.
v = vehicle velocity at each time step, k, starting from k = 1. For
tests completed under this section, v is the vehicle velocity from
the vehicle model in Sec.  1036.545. Note that this should include
charge-depleting test intervals that start when the engine is not
yet operating.
[Delta]t = 1/frecord
frecord = the record rate.
Example using the charge-depletion test in Figure 1 of Sec.
1036.510 for the SET for CO2 emission determination:

Q = 24000
v1 = 0 mi/hr
v2 = 0.8 mi/hr
v3 = 1.1 mi/hr
frecord = 10 Hz
[Delta]t = 1/10 Hz = 0.1 s
[GRAPHIC] [TIFF OMITTED] TP27AP23.034

DCD1 = 30.1 mi
DCD2 = 30.0 mi
DCD3 = 30.1 mi
DCD4 = 30.2 mi
DCD5 = 30.1 mi
N = 5
UFDCD1 = 0.11
UFDCD2 = 0.23
UFDCD3 = 0.34
UFDCD4 = 0.45
UFDCD5 = 0.53
eCO2SETCD1 = 0 g/hp[middot]hr
eCO2SETCD2 = 0 g/hp[middot]hr
eCO2SETCD3 = 0 g/hp[middot]hr
eCO2SETCD4 = 0 g/hp[middot]hr
eCO2SETCD5 = 174.4 g/hp[middot]hr
M = 1
eCO2SETCS = 428.1 g/hp[middot]hr
UFRCD = 0.53

[GRAPHIC] [TIFF OMITTED] TP27AP23.035

eUFCO2comp = 215.2 g/hp[middot]hr

    (f) Calculate and evaluate cycle statistics as specified in 40 CFR
1065.514 for nonhybrid engines and Sec.  1036.545 for hybrid engines
and hybrid powertrains.
    (g) Calculate the total emission mass of each constituent, m, over
the test interval as described in 40 CFR 1065.650. For nonhybrid
engines, calculate the total work, W, over the test interval as
described in 40 CFR 1065.650(d). For hybrid engines and hybrid
powertrains, calculate total positive work over the test interval using
system power, Psys. Determine Psys, using Sec.  1036.520(f).

0
21. Amend Sec.  1036.512 by:
0
a. Revising paragraphs (b)(2)(v), (c), (d) introductory text, (d)(1)
and (2)(ii);
0
b. Removing the period in the heading in Figure 1 to paragraph (d)(4);
and
0
c. Revising paragraph (f).

    The revisions read as follows:

Sec.  1036.512  Federal Test Procedure.

* * * * *
    (b) * * *
    (2) * * *
    (v) For plug-in hybrid engines and plug-in hybrid powertrains, test
over the FTP in both charge-sustaining and charge-depleting operation
for both criteria and greenhouse gas pollutant determination.
    (c) The FTP duty cycle consists of an initial run through the test
interval from a cold start as described in 40 CFR part 1065, subpart F,
followed by a (20 1) minute hot soak with no engine
operation, and then a final hot start run through the same transient
test interval. Engine starting is part of both the cold-start and hot-
start test intervals. Calculate the total emission mass of each
constituent, m, over each test interval as described in 40 CFR
1065.650. For nonhybrid engines, calculate the total work, W, over the
test interval as described in 40 CFR 1065.650(d). For hybrid engines
and hybrid powertrains, calculate total positive work over each test
interval using system power, Psys. Determine Psys
using Sec.  1036.520(f). For powertrains with automatic transmissions,
account for and include the work produced by the engine from the CITT
load. Calculate the official transient emission result from the cold-
start and hot-start test intervals using the following equation:
[GRAPHIC] [TIFF OMITTED] TP27AP23.036

    (d) Determine criteria pollutant emissions for plug-in hybrid
engines and plug-in hybrid powertrains as follows:
    (1) Precondition the engine or powertrain in charge-sustaining
mode. Perform testing as described in this section for hybrid engines
or hybrid powertrains in charge-sustaining mode.
    (2) * * *
    (ii) Operate the engine or powertrain over one FTP duty cycle
followed by alternating repeats of a 20-minute soak and a hot start
test interval until you reach the end-of-test criteria defined in 40
CFR 1066.501.
* * * * *
    (f) Calculate and evaluate cycle statistics as specified in 40 CFR
1065.514 for nonhybrid engines and Sec.  1036.545 for hybrid engines
and hybrid powertrains.
0
22. Revise Sec.  1036.514 to read as follows:

Sec.  1036.514  Low Load Cycle.

    (a) Measure emissions using the transient Low Load Cycle (LLC) as
described in this section to determine whether engines meet the LLC
emission standards in Sec.  1036.104.
    (b) The LLC duty cycle is described in paragraph (d) of appendix B
of this part. The following procedures apply differently for testing
nonhybrid engines, hybrid engines, and hybrid powertrains:
    (1) For nonhybrid engine testing, use the following procedures:
    (i) Use the normalized speed and torque values for engine testing
in the LLC duty cycle described in paragraph (d) of appendix B of this
part.
    (ii) Denormalize speed and torque values as described in 40 CFR
1065.512 and 1065.610 with the following additional requirements:
    (A) The accessory load at idle described in paragraph (c) of this
section must be applied using the optional declared idle power in 40
CFR 1065.510(f)(6). Use of the optional declared idle torque in 40 CFR
1065.510(f)(5)(iii) is not allowed and must be zero.
    (B) Replace paragraph 40 CFR 1065.610(d)(3)(vi) with the following:
    (1) For all other idle segments less than or equal to 200 s in
length, set the reference speed and torque values to the warm-idle-in-
drive values. This is to represent the transmission operating in drive.
    (2) For idle segments more than 200 s in length, set the reference
speed and torque values to the warm-idle-in-drive values for the first
three seconds and the last three seconds of the idle segment. For all
other points in the idle segment set the reference speed and torque
values to the warm-idle-in-neutral values. This is to represent the
transmission being manually shifted from drive to neutral near the
beginning of the idle segment and back to drive near the end of the
idle segment.
    (iii) Calculate and evaluate cycle statistics as described in 40
CFR 1065.514. For testing spark-ignition gaseous-fueled engines with
fuel delivery at a single-point in the intake manifold, you may apply
the statistical criteria in Table 1 in this section to validate the
LLC.

Table 1 to Paragraph (b)(1)(iii) of Sec.   1036.514--Statistical Criteria for Validating Duty Cycles for Gaseous-
                                        Fueled Spark-Ignition Engines \a\
----------------------------------------------------------------------------------------------------------------
              Parameter                         Speed                    Torque                   Power
----------------------------------------------------------------------------------------------------------------
Slope, a1............................  .......................  0.800 <=a1 <=1.030.....  0.800 <=a1 <=1.030.
Absolute value of intercept,
 [verbar]a0[verbar].
Standard error of the estimate, SEE..  .......................  .......................  <=15% of maximum mapped
                                                                                power.
Coefficient of determination, r2.....  .......................  >=0.650................  >=0.650.
----------------------------------------------------------------------------------------------------------------
\a\ Statistical criteria apply as specified in 40 CFR 1065.514 unless otherwise specified.

    (2) Test hybrid engines and hybrid powertrains as described in
Sec.  1036.510(b)(2), with the following exceptions:
    (i) Replace Pcontrated with Prated, which is
the peak rated power determined in Sec.  1036.520.
    (ii) Keep the transmission in drive for all idle segments 200
seconds or less. For idle segments more than 200 seconds, leave the
transmission in drive for the first 3 seconds of the idle segment,
place the transmission in park or neutral immediately after the 3rd
second in the idle segment, and shift the transmission into drive again
3 seconds before the end of the idle segment which is defined by the
first nonzero vehicle speed setpoint.
    (iii) For hybrid engines, select the transmission from Table 1 of
Sec.  1036.540, substituting ``engine'' for ``vehicle''.
    (iv) For hybrid engines, you may request to change the GEM-
generated engine reference torque at idle to better represent curb idle
transmission torque (CITT).
    (v) For plug-in hybrid engines and plug-in hybrid powertrains,
determine criteria pollutant and greenhouse gas emissions as described
in Sec.  1036.510(d) and (e), replacing ``SET'' with ``LLC''.
    (vi) Calculate and evaluate cycle statistics as specified in Sec.
1036.545.
    (c) Apply a vehicle accessory load for each idle point in the cycle
based on a constant power. Use the power values in Table 2 to paragraph
(c)(3) of this section based on primary intended service class. For
nonhybrid engine testing, this is in addition to any applicable CITT.
Additional provisions related to vehicle accessory load apply for the
following special cases:
    (1) For engines with stop-start technology, account for the loss of
mechanical work due to the lack of any idle accessory load during
engine-off conditions by determining the total loss of mechanical work
from idle accessory load during all engine-off intervals over the
entire test interval and distributing that work over the engine-on
intervals of the entire test interval based on a calculated average
power. You may determine the engine-off time by running practice cycles
or through engineering analysis.
    (2) Apply vehicle accessory power loads on idle points for hybrid
powertrain testing where torque is measured at the axle input shaft or
wheel hubs either as a mechanical or electrical load.
    (3) Table 2 follows:

 Table 2 to Paragraph (c)(3) of Sec.   1036.514--Accessory Load at Idle
------------------------------------------------------------------------
                                                               Power
                                                           representing
             Primary intended service class               accessory load
                                                               (kW)
------------------------------------------------------------------------
Light HDE...............................................             1.5
Medium HDE..............................................             2.5
Heavy HDE...............................................             3.5
------------------------------------------------------------------------

    (d) The test sequence consists of preconditioning the engine by
running one or two FTPs with each FTP followed by (20 1)
minutes with no engine operation and a hot start run through the LLC.
You may start any preconditioning FTP with a hot engine. Perform
testing as described in 40 CFR 1065.530 for a test interval that
includes engine starting. Calculate the total emission mass of each
constituent, m, over the test interval as described in 40 CFR 1065.650.
For nonhybrid engines, calculate the total work, W, over the test
interval as described in 40 CFR 1065.650(d). For hybrid engines and
hybrid powertrains, calculate total positive work over the test
interval using system power, Psys. Determine Psys using Sec.
1036.520(f). For powertrains with automatic transmissions, account for
and include the work produced by the engine from the CITT load.
0
23. Amend Sec.  1036.520 by revising the introductory text, paragraphs
(b) introductory text, (d)(2) and (3), (h), and (i)(2) to read as
follows:

Sec.  1036.520  Determining power and vehicle speed values for
powertrain testing.

    This section describes how to determine the system peak power and
continuous rated power of hybrid and nonhybrid powertrain systems and
the vehicle speed for carrying out duty-cycle testing under this part
and Sec.  1036.545.
* * * * *
    (b) Set up the powertrain test according to Sec.  1036.545, with
the following exceptions:
* * * * *
    (d) * * *
    (2) Set maximum driver demand for a full load acceleration at 6.0%
road grade with an initial vehicle speed of 0 mi/hr, continuing for 268
seconds. You may decrease the road grade in the first 30 seconds or
increase initial vehicle speed up to 5 mi/hr as needed to mitigate
clutch slip.
    (3) Linearly ramp the grade from 6.0% down to 0.0% over 300
seconds. Stop the test after the acceleration is less than 0.02 m/s\2\.
* * * * *
    (h) Determine rated power, Prated, as the maximum measured power
from the data collected in paragraph (d)(2) of this section where the
COV determined in paragraph (g) of this section is less than 2%.
    (i) * * *
    (2) For hybrid powertrains, Pcontrated is the maximum measured
power from the data collected in paragraph (d)(3) of this section where
the COV determined in paragraph (g) of this section is less than 2%.
* * * * *
0
24. Amend Sec.  1036.525 by revising the introductory text to read as
follows:

Sec.  1036.525  Clean Idle test.

    Measure emissions using the procedures described in this section to
determine whether engines and hybrid powertrains meet the clean idle
emission standards in Sec.  1036.104(b). For plug-in hybrid engines and
plug-in hybrid powertrains, perform the test with the hybrid function
disabled.
* * * * *
0
25. Amend Sec.  1036.530 by adding paragraph (j) to read as follows:

Sec.  1036.530  Test procedures for off-cycle testing.

* * * * *

    (j) Fuel other than carbon-containing. The following procedures
apply for testing engines using at least one fuel that is not a carbon-
containing fuel:
    (1) Use the following equation to determine
mCO2,norm,testinterval instead of Eq. 1036.530-2:
[GRAPHIC] [TIFF OMITTED] TP27AP23.037

Where:

Wtestinterval = total positive work over the test
interval as determined in 40 CFR 1065.650.
Pmax = the highest value of rated power for all the
configurations included in the engine family.
ttestinterval = duration of the test interval. Note that
the nominal value is 300 seconds.

Example:

Wtestinterval = 8.95 hp[middot]hr
Pmax = 406.5 hp
ttestinterval = 300.01 s = 0.08 hr
[GRAPHIC] [TIFF OMITTED] TP27AP23.038

mCO2,norm,testinterval = 0.2722
mCO2,norm,testinterval = 27.22%

    (2) Determine off-cycle emissions quantities as follows:
    (i) For engines subject to spark-ignition standards, use the
following equation instead of Eq. 1036.530-3:
[GRAPHIC] [TIFF OMITTED] TP27AP23.039

Where:

    m[emission] = total emission mass for a given
pollutant over the test interval as determined in paragraph (d)(2)
of this section.
    Wtestinterval = total positive work over the test
interval as determined in 40 CFR 1065.650.
    Example:

mNOx = 1.337 g
Wtestinterval = 38.2 hp[middot]hr
[GRAPHIC] [TIFF OMITTED] TP27AP23.040

eNOx,offcycle = 0.035 g/hp[middot]hr

    (ii) For engines subject to compression-ignition standards, use Eq.
1036.530-4 to determine the off-cycle emission quantity for bin 1.
    (iii) For engines subject to compression-ignition standards, use
the following equation instead of Eq. 1036.530-5 to determine the off-
cycle emission quantity for bin 2:
[GRAPHIC] [TIFF OMITTED] TP27AP23.041

Where:

i = an indexing variable that represents one 300 second test
interval.
N = total number of 300 second test intervals in bin 2.
m[emission],testinterval,i = total emission mass for a
given pollutant over the test interval i in bin 2 as determined in
paragraph (d)(2) of this section.
Wtestinterval,i = total positive work over the test
interval i in bin 2 as determined in 40 CFR 1065.650.
    Example:

N = 15439
mNOx1 = 0.546 g
mNOx2 = 0.549 g
mNOx3 = 0.556 g
Wtestinterval1 = 8.91 hp[middot]hr
Wtestinterval2 = 8.94 hp[middot]hr
Wtestinterval3 = 8.89 hp[middot]hr
[GRAPHIC] [TIFF OMITTED] TP27AP23.042

eNOx,offcycle,bin2 = 0.026 g/hp[middot]hr

0
26. Amend Sec.  1036.535 by revising paragraphs (b)(1)(ii) introductory
text, (b)(1)(ii)(B), (b)(1)(iii), and (b)(10) to read as follows:

Sec.  1036.535  Determining steady-state engine fuel maps and fuel
consumption at idle.

* * * * *
    (b) * * *
    (1) * * *
    (ii) Select the following required torque setpoints at each of the
selected speed setpoints: zero (T = 0), maximum mapped torque, Tmax
mapped, and eight (or more) equally spaced points between T = 0 and
Tmax mapped. Select the maximum torque setpoint at each speed to
conform to the torque map as follows:
* * * * *
    (B) Select Tmax at each speed setpoint as a single
torque value to represent all

the default torque setpoints above the value determined in paragraph
(b)(1)(ii)(A) of this section. All of the other default torque
setpoints less than Tmax at a given speed setpoint are
required torque setpoints.
    (iii) You may select any additional speed and torque setpoints
consistent with good engineering judgment. For example you may need to
select additional points if the engine's fuel consumption is nonlinear
across the torque map. Avoid creating a problem with interpolation
between narrowly spaced speed and torque setpoints near
Tmax. For each additional speed setpoint, we recommend
including a torque setpoint of Tmax; however, you may select
torque setpoints that properly represent in-use operation. Increments
for torque setpoints between these minimum and maximum values at an
additional speed setpoint must be no more than one-ninth of
Tmax,mapped. Note that if the test points were added for the
child rating, they should still be reported in the parent fuel map. We
will test with at least as many points as you. If you add test points
to meet testing requirements for child ratings, include those same test
points as reported values for the parent fuel map. For our testing, we
will use the same normalized speed and torque test points you use, and
we may select additional test points.
* * * * *
    (10) Correct the measured or calculated mean fuel mass flow rate,
at each of the operating points to account for mass-specific net energy
content as described in paragraph (e) of this section.
* * * * *
0
27. Amend Sec.  1036.540 by revising paragraph (b) to read as follows:

Sec.  1036.540  Determining cycle-average engine fuel maps.

* * * * *
    (b) General test provisions. The following provisions apply for
testing under this section:
    (1) Measure NOX emissions for each specified sampling
period in grams. You may perform these measurements using a
NOX emission-measurement system that meets the requirements
of 40 CFR part 1065, subpart J. Include these measured NOX
values any time you report to us your fuel-consumption values from
testing under this section. If a system malfunction prevents you from
measuring NOX emissions during a test under this section but
the test otherwise gives valid results, you may consider this a valid
test and omit the NOX emission measurements; however, we may
require you to repeat the test if we determine that you inappropriately
voided the test with respect to NOX emission measurement.
    (2) The provisions related to carbon balance error verification in
Sec.  1036.543 apply for all testing in this section. These procedures
are optional, but we will perform carbon balance error verification for
all testing under this section.
    (3) Correct fuel mass to a mass-specific net energy content of a
reference fuel as described in paragraph (d)(13) of this section.
    (4) This section uses engine parameters and variables that are
consistent with 40 CFR part 1065.
* * * * *
0
28. Revise Sec.  1036.543 to read as follows:

Sec.  1036.543  Carbon balance error verification.

    The optional carbon balance error verification in 40 CFR 1065.543
compares independent assessments of the flow of carbon through the
system (engine plus aftertreatment). This procedure applies for each
individual interval in Sec. Sec.  1036.535(b), (c), and (d), 1036.540,
and 1036.545.
0
29. Add Sec.  1036.545 to read as follows:

Sec.  1036.545  Powertrain testing.

    This section describes the procedure to measure fuel consumption
and create engine fuel maps by testing a powertrain that includes an
engine coupled with a transmission, drive axle, and hybrid components
or any assembly with one or more of those hardware elements. Engine
fuel maps are part of demonstrating compliance with Phase 2 and Phase 3
vehicle standards under 40 CFR part 1037; the powertrain test procedure
in this section is one option for generating this fuel-mapping
information as described in Sec.  1036.505. Additionally, this
powertrain test procedure is one option for certifying hybrid engines
and hybrid powertrains to the engine standards in Sec. Sec.  1036.104
and 1036.108.
    (a) General test provisions. The following provisions apply broadly
for testing under this section:
    (1) Measure NOX emissions as described in paragraph (k)
of this section. Include these measured NOX values any time
you report to us your greenhouse gas emissions or fuel consumption
values from testing under this section.
    (2) The procedures of 40 CFR part 1065 apply for testing in this
section except as specified. This section uses engine parameters and
variables that are consistent with 40 CFR part 1065.
    (3) Powertrain testing depends on models to calculate certain
parameters. You can use the detailed equations in this section to
create your own models, or use the GEM HIL model contained within GEM
Phase 2, Version 4.0 (incorporated by reference, see Sec.  1036.810) to
simulate vehicle hardware elements as follows:
    (i) Create driveline and vehicle models that calculate the angular
speed setpoint for the test cell dynamometer, fnref,dyno,
based on the torque measurement location. Use the detailed equations in
paragraph (f) of this section, the GEM HIL model's driveline and
vehicle submodels, or a combination of the equations and the submodels.
You may use the GEM HIL model's transmission submodel in paragraph (f)
of this section to simulate a transmission only if testing hybrid
engines.
    (ii) Create a driver model or use the GEM HIL model's driver
submodel to simulate a human driver modulating the throttle and brake
pedals to follow the test cycle as closely as possible.
    (iii) Create a cycle-interpolation model or use the GEM HIL model's
cycle submodel to interpolate the duty-cycles and feed the driver model
the duty-cycle reference vehicle speed for each point in the duty-
cycle.
    (4) The powertrain test procedure in this section is designed to
simulate operation of different vehicle configurations over specific
duty cycles. See paragraphs (h) and (j) of this section.
    (5) For each test run, record engine speed and torque as defined in
40 CFR 1065.915(d)(5) with a minimum sampling frequency of 1 Hz. These
engine speed and torque values represent a duty cycle that can be used
for separate testing with an engine mounted on an engine dynamometer
under 40 CFR 1037.551, such as for a selective enforcement audit as
described in 40 CFR 1037.301.
    (6) For hybrid powertrains with no plug-in capability, correct for
the net energy change of the energy storage device as described in 40
CFR 1066.501. For plug-in hybrid electric powertrains, follow 40 CFR
1066.501 to determine End-of-Test for charge-depleting operation. You
must get our approval in advance for your utility factor curve; we will
approve it if you can show that you created it, using good engineering
judgment, from sufficient in-use data of vehicles in the same
application as the vehicles in which the plug-in hybrid electric
powertrain will be installed. You may use methodologies described in
SAE J2841 to develop the utility factor curve.

    (7) The provisions related to carbon balance error verification in
Sec.  1036.543 apply for all testing in this section. These procedures
are optional if you are only performing direct or indirect fuel-flow
measurement, but we will perform carbon balance error verification for
all testing under this section.
    (8) Do not apply accessory loads when conducting a powertrain test
to generate inputs to GEM if torque is measured at the axle input shaft
or wheel hubs.
    (9) If you test a powertrain over the duty cycle specified in Sec.
1036.514, control and apply the electrical accessory loads using one of
the following systems:
    (i) An alternator with dynamic electrical load control.
    (ii) A load bank connected directly to the powertrain's electrical
system.
    (10) The following instruments are required with plug-in hybrid
systems to determine required voltages and currents during testing and
must be installed on the powertrain to measure these values during
testing:
    (i) Measure the voltage and current of the battery pack directly
with a DC wideband power analyzer to determine power. Measure all
current entering and leaving the battery pack. Do not measure voltage
upstream of this measurement point. The maximum integration period for
determining amp-hours is 0.05 seconds. The power analyzer must have an
accuracy for measuring current and voltage of 1% of point or 0.3% of
maximum, whichever is greater. The power analyzer must not be
susceptible to offset errors while measuring current.
    (ii) If safety considerations do not allow for measuring voltage,
you may determine the voltage directly from the powertrain ECM.
    (11) The following figure provides an overview of the steps
involved in carrying out testing under this section:

Figure 1 to Paragraph (a)(11) of Sec.  1036.545--Overview of Powertrain
Testing
[GRAPHIC] [TIFF OMITTED] TP27AP23.043

    (b) Test configuration. Select a powertrain for testing as
described in 40 CFR 1037.235 or Sec.  1036.235 as applicable. Set up
the engine according to 40 CFR 1065.110 and 40 CFR 1065.405(b). Set the
engine's idle speed to idle speed defined in 40 CFR 1037.520(h)(1).
    (1) The default test configuration consists of a powertrain with
all components upstream of the axle. This involves connecting the
powertrain's output shaft directly to the dynamometer or to a gear box
with a fixed gear ratio and measuring torque at the axle input shaft.
You may instead set up the dynamometer to connect at the wheel hubs and
measure torque at that location. The preceding sentence may apply if
your powertrain configuration requires it, such as for hybrid
powertrains or if you want to represent the axle performance with
powertrain test results. Alternately you may test the powertrain with a
chassis dynamometer as long as you measure speed and torque at the
powertrain's output shaft or wheel hubs.
    (2) For testing hybrid engines, connect the engine's crankshaft
directly to the dynamometer and measure torque at that location.
    (c) Powertrain temperatures during testing. Cool the powertrain
during testing so temperatures for oil, coolant, block, head,
transmission, battery, and power electronics are within the
manufacturer's expected ranges for normal operation. You may use
electronic control module outputs to comply with this paragraph (c).
You may use auxiliary coolers and fans.
    (d) Engine break in. Break in the engine according to 40 CFR
1065.405, the axle assembly according to 40 CFR 1037.560, and the
transmission according to 40 CFR 1037.565. You may instead break in the
powertrain as a complete system using the engine break in procedure in
40 CFR 1065.405.
    (e) Dynamometer setup. Set the dynamometer to operate in speed-
control mode (or torque-control mode for hybrid engine testing at idle,
including idle portions of transient duty cycles). Record data as
described in 40 CFR 1065.202. Command and control the dynamometer speed
at a minimum of 5 Hz, or 10 Hz for testing hybrid engines. Run the
vehicle model to calculate the dynamometer setpoints at a rate of at
least 100 Hz. If the dynamometer's command frequency is less than the
vehicle model dynamometer setpoint frequency, subsample the calculated
setpoints for commanding the dynamometer setpoints.
    (f) Driveline and vehicle model. Use the GEM HIL model's driveline
and vehicle submodels or the equations in this paragraph (f) to
calculate the dynamometer speed setpoint, fnref,dyno, based
on the torque measurement location. For all powertrains, configure GEM
with the accessory load set to zero. For hybrid engines, configure GEM
with the applicable accessory load as specified in Sec. Sec.  1036.505
and 1036.514. For all powertrains and hybrid engines, configure GEM
with the tire slip model disabled.
    (1) Driveline model with a transmission in hardware. For testing
with torque measurement at the axle input shaft or wheel hubs,
calculate, fnref,dyno, using the GEM HIL model's driveline submodel or
the following equation:
[GRAPHIC] [TIFF OMITTED] TP27AP23.044

Where:

ka[speed] = drive axle ratio as determined in paragraph
(h) of this section. Set ka[speed] equal to 1.0 if torque
is measured at the wheel hubs.
vrefi = simulated vehicle reference speed as calculated
in paragraph (f)(3) of this section.
r[speed] = tire radius as determined in paragraph (h) of
this section.

    (2) Driveline model with a simulated transmission. For testing with
the torque measurement at the engine's crankshaft,
fnref,dyno is the dynamometer target speed from the GEM HIL
model's transmission submodel. You may request our approval to change
the transmission submodel, as long as the changes do not affect the
gear selection logic. Before testing, initialize the transmission model
with the engine's measured torque curve and the applicable steady-state
fuel map from the GEM HIL model. You may request our approval to input
your own steady-state fuel map. For example, this request for approval
could include using a fuel map that represents the combined performance
of the engine and hybrid components. Configure the torque converter to
simulate neutral idle when using this procedure to generate engine fuel
maps in Sec.  1036.505 or to perform the Supplemental Emission Test
(SET) testing under Sec.  1036.510. You may change engine commanded
torque at idle to better represent CITT for transient testing under
Sec.  1036.512. You may change the simulated engine inertia to match
the inertia of the engine under test. We will evaluate your requests
under this paragraph (f)(2) based on your demonstration that that the
adjusted testing better represents in-use operation.
    (i) The transmission submodel needs the following model inputs:
    (A) Torque measured at the engine's crankshaft.
    (B) Engine estimated torque determined from the electronic control
module or by converting the instantaneous operator demand to an
instantaneous torque in N[middot]m.
    (C) Dynamometer mode when idling (speed-control or torque-control).
    (D) Measured engine speed when idling.
    (E) Transmission output angular speed, fni,transmission, calculated
as follows:
[GRAPHIC] [TIFF OMITTED] TP27AP23.045

Where:

ka[speed] = drive axle ratio as determined in paragraph
(h) of this section.
vrefi = simulated vehicle reference speed as calculated
in paragraph (f)(3) of this section.
r[speed] = tire radius as determined in paragraph (h) of
this section.

    (ii) The transmission submodel generates the following model
outputs:
    (A) Dynamometer target speed.
    (B) Dynamometer idle load.
    (C) Transmission engine load limit.
    (D) Engine speed target.
    (3) Vehicle model. Calculate the simulated vehicle reference speed,
[nu]refi, using the GEM HIL model's vehicle submodel or the
equations in this paragraph (f)(3):

[GRAPHIC] [TIFF OMITTED] TP27AP23.046

Where:

i = a time-based counter corresponding to each measurement during
the sampling period.
Let vref1 = 0; start calculations at i = 2. A 10-minute
sampling period will generally involve 60,000 measurements.
T = instantaneous measured torque at the axle input, measured at the
wheel hubs, or simulated by the GEM HIL model's transmission
submodel. For configurations with multiple torque measurements, for
example when measuring torque at the wheel hubs, T is the sum of all
torque measurements.
Effaxle = axle efficiency. Use Effaxle = 0.955
for T >= 0, and use Effaxle = 1/0.955 for T < 0. Use
Effaxle = 1.0 if torque is measured at the wheel hubs.
M = vehicle mass for a vehicle class as determined in paragraph (h)
of this section.
g = gravitational constant = 9.80665 m/s\2\.
Crr = coefficient of rolling resistance for a vehicle
class as determined in paragraph (h) of this section.
Gi-1 = the percent grade interpolated at distance,
Di-1, from the duty cycle in appendix D to this part
corresponding to measurement (i-1).
[GRAPHIC] [TIFF OMITTED] TP27AP23.047

[rho] = air density at reference conditions. Use [rho] = 1.1845 kg/
m\3\.
CdA = drag area for a vehicle class as determined in
paragraph (h) of this section.
Fbrake,i-1 = instantaneous braking force applied by the
driver model.
[GRAPHIC] [TIFF OMITTED] TP27AP23.048

[Delta]t = the time interval between measurements. For example, at
100 Hz, [Delta]t = 0.0100 seconds.
Mrotating = inertial mass of rotating components. Let
Mrotating = 340 kg for vocational Light HDV or vocational
Medium HDV. See paragraph (h) of this section for tractors and for
vocational Heavy HDV.

    (4) Example. The following example illustrates a calculation of
fnref,dyno using paragraph (f)(1) of this section where
torque is measured at the axle input shaft. This example is for a
vocational Light HDV or vocational Medium HDV with 6 speed automatic
transmission at B speed (Test 4 in Table 1 to paragraph (h)(2)(ii) of
this section).

[GRAPHIC] [TIFF OMITTED] TP27AP23.049

    (g) Driver model. Use the GEM HIL model's driver submodel or design
a driver model to simulate a human driver modulating the throttle and
brake pedals. In either case, tune the model to follow the test cycle
as closely as possible meeting the following specifications:
    (1) The driver model must meet the following speed requirements:
    (i) For operation over the highway cruise cycles, the speed
requirements described in 40 CFR 1066.425(b) and (c).
    (ii) For operation over the transient cycle specified in appendix A
of this part, the SET as defined Sec.  1036.510, the Federal Test
Procedure (FTP) as defined in Sec.  1036.512, and the Low Load Cycle
(LLC) as defined in Sec.  1036.514, the speed requirements described in
40 CFR 1066.425(b) and (c).
    (iii) The exceptions in 40 CFR 1066.425(b)(4) apply to the highway
cruise cycles, the transient cycle specified in appendix A of this
part, SET, FTP, and LLC.
    (iv) If the speeds do not conform to these criteria, the test is
not valid and must be repeated.
    (2) Send a brake signal when operator demand is zero and vehicle
speed is greater than the reference vehicle speed from the test cycle.
Include a delay before changing the brake signal to prevent dithering,
consistent with good engineering judgment.
    (3) Allow braking only if operator demand is zero.
    (4) Compensate for the distance driven over the duty cycle over the
course of the test. Use the following equation to perform the
compensation in real time to determine your time in the cycle:
[GRAPHIC] [TIFF OMITTED] TP27AP23.050

Where:

vvehicle = measured vehicle speed.
vcycle = reference speed from the test cycle. If
vcycle,i-1 < 1.0 m/s, set
vcycle,i-1 = vvehiclei-1

    (h) Vehicle configurations to evaluate for generating fuel maps as
defined in Sec.  1036.505. Configure the driveline and vehicle models
from paragraph (f) of this section in the test cell to test the
powertrain. Simulate multiple vehicle configurations that represent the
range of intended vehicle applications using one of the following
options:
    (1) For known vehicle configurations, use at least three equally
spaced axle ratios or tire sizes and three different road loads (nine
configurations), or at least four equally spaced axle ratios or tire
sizes and two different road loads (eight configurations). Select axle
ratios to represent the full range of expected vehicle installations.
Select axle ratios and tire sizes such that the ratio of

engine speed to vehicle speed covers the range of ratios of minimum and
maximum engine speed to vehicle speed when the transmission is in top
gear for the vehicles in which the powertrain will be installed. Note
that you do not have to use the same axle ratios and tire sizes for
each GEM regulatory subcategory. You may determine appropriate
Crr, CdA, and mass values to cover the range of
intended vehicle applications or you may use the Crr,
CdA, and mass values specified in paragraph (h)(2) of this
section.
    (2) If vehicle configurations are not known, determine the vehicle
model inputs for a set of vehicle configurations as described in Sec.
1036.540(c)(3) with the following exceptions:
    (i) In the equations of Sec.  1036.540(c)(3)(i),
ktopgear is the actual top gear ratio of the powertrain
instead of the transmission gear ratio in the highest available gear
given in Table 1 in Sec.  1036.540.
    (ii) Test at least eight different vehicle configurations for
powertrains that will be installed in Spark-ignition HDE, vocational
Light HDV, and vocational Medium HDV using the following table instead
of Table 2 in Sec.  1036.540:
[GRAPHIC] [TIFF OMITTED] TP27AP23.051

    (iii) Select and test vehicle configurations as described in Sec.
1036.540(c)(3)(iii) for powertrains that will be installed in
vocational Heavy HDV and tractors using the following tables instead of
Table 3 and Table 4 in Sec.  1036.540:
[GRAPHIC] [TIFF OMITTED] TP27AP23.052

[GRAPHIC] [TIFF OMITTED] TP27AP23.053

    (3) For hybrid powertrain systems where the transmission will be
simulated, use the transmission parameters defined in Sec.
1036.540(c)(2) to determine transmission type and gear ratio. Use a
fixed transmission efficiency of 0.95. The GEM HIL transmission model
uses a transmission parameter file for each test that includes the
transmission type, gear ratios, lockup gear, torque limit per gear from
Sec.  1036.540(c)(2), and the values from Sec.  1036.505(b)(4) and (c).
    (i) [Reserved]
    (j) Duty cycles to evaluate. Operate the powertrain over each of
the duty cycles specified in 40 CFR 1037.510(a)(2), and for each
applicable vehicle configuration from paragraph (h) of this section.
Determine cycle-average powertrain fuel maps by testing the powertrain
using the procedures in Sec.  1036.540(d) with the following
exceptions:
    (1) Understand ``engine'' to mean ``powertrain''.
    (2) Warm up the powertrain as described in Sec.  1036.520(c)(1).
    (3) Within 90 seconds after concluding the warm-up, start the
transition to the preconditioning cycle as described in paragraph
(j)(5) of this section.
    (4) For plug-in hybrid engines, precondition the battery and then
complete all back-to-back tests for each vehicle configuration
according to 40 CFR 1066.501 before moving to the next vehicle
configuration. Figure 2 of this section provides an example of a
charge-depleting test sequence where there are two test intervals that
contain engine operation. Figure 2 follows:

Figure 2 to Paragraph (j)(4) of Sec.  1036.545--Generic Duty-Cycle
Cycle Charge-Depleting Test Sequence
[GRAPHIC] [TIFF OMITTED] TP27AP23.054

    (5) If the preceding duty cycle does not end at 0 mi/hr, transition
between duty cycles by decelerating at a rate of 2 mi/hr/s at 0% grade
until the vehicle reaches zero speed. Shut off the powertrain. Prepare
the powertrain and test cell for the next duty-cycle.

    (6) Start the next duty-cycle within 60 to 180 seconds after
shutting off the powertrain.
    (i) To start the next duty-cycle, for hybrid powertrains, key on
the vehicle and then start the duty-cycle. For conventional powertrains
key on the vehicle, start the engine, wait for the engine to stabilize
at idle speed, and then start the duty-cycle.
    (ii) If the duty-cycle does not start at 0 mi/hr, transition to the
next duty cycle by accelerating at a target rate of 1 mi/hr/s at 0%
grade. Stabilize for 10 seconds at the initial duty cycle conditions
and start the duty-cycle.
    (7) Calculate cycle work using GEM or the speed and torque from the
driveline and vehicle models from paragraph (f) of this section to
determine the sequence of duty cycles.
    (8) Calculate the mass of fuel consumed for idle duty cycles as
described in paragraph (n) of this section.
    (k) Measuring NOX emissions. Measure NOX
emissions for each sampling period in grams. You may perform these
measurements using a NOX emission-measurement system that
meets the requirements of 40 CFR part 1065, subpart J. If a system
malfunction prevents you from measuring NOX emissions during
a test under this section but the test otherwise gives valid results,
you may consider this a valid test and omit the NOX emission
measurements; however, we may require you to repeat the test if we
determine that you inappropriately voided the test with respect to
NOX emission measurement.
    (l) [Reserved]
    (m) Measured output speed validation. For each test point, validate
the measured output speed(s) with the corresponding reference values.
For test setups where speed is measured at multiple locations, each
location must meet the requirements in this paragraph (m). If the range
of reference speed is less than 10 percent of the mean reference speed,
you need to meet only the standard error of the estimate in Table 1 of
this section. You may delete points when the vehicle is stopped. If
your speed measurement is not at the location of fnref, correct your
measured speed using the constant speed ratio between the two
locations. Apply cycle-validation criteria for each separate transient
or highway cruise cycle based on the following parameters:

  Table 4 to Paragraph (m) of Sec.   1036.545--Statistical Criteria for
                         Validating Duty Cycles
------------------------------------------------------------------------
               Parameter \a\                        Speed control
------------------------------------------------------------------------
Slope, a1.................................  0.990 <= a1 <= 1.010.
Absolute value of intercept,                <=2.0% of maximum fnref
 [verbar]a0[verbar].                         speed.
Standard error of the estimate, SEE.......  <=2.0% of maximum fnref
                                             speed.
Coefficient of determination, r2..........  >=0.990.
------------------------------------------------------------------------
\a\ Determine values for specified parameters as described in 40 CFR
  1065.514(e) by comparing measured and reference values for fnref,dyno.

    (n) Fuel consumption at idle. Record measurements using direct and/
or indirect measurement of fuel flow. Determine the fuel-consumption
rates at idle for the applicable duty cycles described in 40 CFR
1037.510(a)(2) as follows:
    (1) Direct fuel flow measurement. Determine the corresponding mean
values for mean idle fuel mass flow rate, mifuelidle, for
each duty cycle, as applicable. Use of redundant direct fuel-flow
measurements require our advance approval.
    (2) Indirect fuel flow measurement. Record speed and torque and
measure emissions and other inputs needed to run the chemical balance
in 40 CFR 1065.655(c). Determine the corresponding mean values for each
duty cycle. Use of redundant indirect fuel-flow measurements require
our advance approval. Measure background concentration as described in
Sec.  1036.535(b)(4)(ii). We recommend setting the CVS flow rate as low
as possible to minimize background, but without introducing errors
related to insufficient mixing or other operational considerations.
Note that for this testing 40 CFR 1065.140(e) does not apply, including
the minimum dilution ratio of 2:1 in the primary dilution stage.
Calculate the idle fuel mass flow rate for each duty cycle,
mifuelidle, for each set of vehicle settings, as follows:
[GRAPHIC] [TIFF OMITTED] TP27AP23.055

Where:

MC = molar mass of carbon.
wCmeas = carbon mass fraction of fuel (or mixture of test
fuels) as determined in 40 CFR 1065.655(d), except that you may not
use the default properties in Table 2 of 40 CFR 1065.655 to
determine [alpha], [beta], and wC for liquid fuels.
niexh = the mean raw exhaust molar flow rate from which
you measured emissions according to 40 CFR 1065.655.
xCcombdry = the mean concentration of carbon from fuel
and any injected fluids in the exhaust per mole of dry exhaust.
xH2Oexhdry = the mean concentration of H2O in
exhaust per mole of dry exhaust.
miCO2DEF = the mean CO2 mass emission rate
resulting from diesel exhaust fluid decomposition over the duty
cycle as determined in Sec.  1036.535(b)(9). If your engine does not
use diesel exhaust fluid, or if you choose not to perform this
correction, set equal to 0.
MCO2 = molar mass of carbon dioxide.

    Example:

[GRAPHIC] [TIFF OMITTED] TP27AP23.056

    (o) Create GEM inputs. Use the results of powertrain testing to
determine GEM inputs for the different simulated vehicle configurations
as follows:
    (1) Correct the measured or calculated fuel masses,
mfuel[cycle], and mean idle fuel mass flow rates,
mifuelidle, if applicable, for each test result to a mass-
specific net energy content of a reference fuel as described in Sec.
1036.535(e), replacing mean fuel with mifuelidle with
mfuel[cycle] where applicable in Eq. 1036.535-4.
    (2) Declare fuel masses, mfuel[cycle] and
mifuelidle. Determine mfuel[cycle] using the
calculated fuel mass consumption values described in Sec.
1036.540(d)(12). In addition, declare mean fuel mass flow rate for each
applicable idle duty cycle, mifuelidle. These declared
values may not be lower than any corresponding measured values
determined in this section. If you use both direct and indirect
measurement of fuel flow, determine the corresponding declared values
as described in Sec.  1036.535(g)(2) and (3). These declared values,
which serve as emission standards, collectively represent the
powertrain fuel map for certification.
    (3) For engines designed for plug-in hybrid electric vehicles, the
mass of fuel for each cycle, mfuel[cycle], is the utility
factor-weighted fuel mass, mfuelUF[cycle]. This is
determined by calculating mfuel for the full charge-
depleting and charge-sustaining portions of the test and weighting the
results, using the following equation:
[GRAPHIC] [TIFF OMITTED] TP27AP23.057

Where:

i = an indexing variable that represents one test interval.
N = total number of charge-depleting test intervals.
mfuel[cycle]CDi = total mass of fuel in the charge-
depleting portion of the test for each test interval, i, starting
from i = 1, including the test interval(s) from the transition
phase.
UFDCDi = utility factor fraction at distance
DCDi from Eq. 40 CFR 1037.505-9 as determined by
interpolating the approved utility factor curve for each test
interval, i, starting from i = 1.
Let UFDCD0 = 0
j = an indexing variable that represents one test interval.
M = total number of charge-sustaining test intervals.
mfuel[cycle]CSj = total mass of fuel over the charge-
sustaining portion of the test for each test interval, j, starting
from j = 1.
UFRCD = utility factor fraction at the full charge-
depleting distance, RCD, as determined by interpolating the approved
utility factor curve. RCD is the cumulative distance driven over N
charge-depleting test intervals.
[GRAPHIC] [TIFF OMITTED] TP27AP23.058

Where:

k = an indexing variable that represents one recorded velocity
value.
Q = total number of measurements over the test interval.
v = vehicle velocity at each time step, k, starting from k = 1. For
tests completed under this section, v is the vehicle velocity as
determined by Eq. 1036.545-1. Note that this should include charge-
depleting test intervals that start when the engine is not yet
operating.
[Delta]t = 1/frecord
frecord = the record rate.

    Example for the 55 mi/hr cruise cycle:

Q = 8790
v1 = 55.0 mi/hr
v2 = 55.0 mi/hr
v3 = 55.1 mi/hr
frecord = 10 Hz
[Delta]t = 1/10 Hz = 0.1 s

[GRAPHIC] [TIFF OMITTED] TP27AP23.059

DCD2 = 13.4 mi
DCD3 = 13.4 mi
N = 3
UFDCD1 = 0.05
UFDCD2 = 0.11
UFDCD3 = 0.21
mfuel55cruiseCD1 = 0 g
mfuel55cruiseCD2 = 0 g
mfuel55cruiseCD3 = 1675.4 g
M = 1
mfuel55cruiseCS = 4884.1 g
UFRCD = 0.21
[GRAPHIC] [TIFF OMITTED] TP27AP23.060

mfuelUF55cruise = 4026.0 g

    (4) For the transient cycle specified in 40 CFR 1037.510(a)(2)(i),
calculate powertrain output speed per unit of vehicle speed,
[GRAPHIC] [TIFF OMITTED] TP27AP23.061

using one of the following methods:
    (i) For testing with torque measurement at the axle input shaft:
    [GRAPHIC] [TIFF OMITTED] TP27AP23.062

    Example:

ka = 4.0
rB = 0.399 m
[GRAPHIC] [TIFF OMITTED] TP27AP23.063

    (ii) For testing with torque measurement at the wheel hubs, use Eq.
1036.545-8 setting ka equal to 1.
    (iii) For testing with torque measurement at the engine's
crankshaft:
[GRAPHIC] [TIFF OMITTED] TP27AP23.064

Where:

fnengine = average engine speed when vehicle speed is at
or above 0.100 m/s.
vref = average simulated vehicle speed at or above 0.100
m/s.

    Example:
    [GRAPHIC] [TIFF OMITTED] TP27AP23.065

    (5) Calculate engine idle speed, by taking the average engine speed
measured during the transient cycle test while the vehicle speed is
below 0.100 m/s. (Note: Use all the charge-sustaining test intervals
when determining engine idle speed for plug-in hybrid engines and plug-
in hybrid powertrains.)
    (6) For the cruise cycles specified in 40 CFR 1037.510(a)(2)(ii),
calculate the average powertrain output speed, fnpowertrain,
and the average powertrain output torque (positive torque only),
Tpowertrain at vehicle speed at or above 0.100 m/s. (Note:
Use all the charge-sustaining and charge-depleting test intervals when
determining fnpowertrain and Tpowertrain for
plug-in hybrid engines and plug-in hybrid powertrains.)
    (7) Calculate positive work, W[cycle], as the work over
the duty cycle at the axle input shaft, wheel hubs, or the engine's
crankshaft, as applicable, when vehicle speed is at or above 0.100 m/s.
For plug-in hybrid engines and plug-in hybrid powertrains, calculate
W[cycle] by calculating the positive work over each of the
charge-sustaining and charge-depleting test intervals and then
averaging them together. For test setups where speed and torque are
measured at multiple locations, determine W[cycle] by
integrating the sum of the power measured at each location.
    (8) The following tables illustrate the GEM data inputs
corresponding to the different vehicle configurations for a given duty
cycle:
    (i) For the transient cycle:

[GRAPHIC] [TIFF OMITTED] TP27AP23.066

    (ii) For the cruise cycles:

  Table 6 to Paragraph (o)(8)(ii) of Sec.   1036.545--Generic Example of Output Matrix for Cruise Cycle Vehicle
                                                 Configurations
----------------------------------------------------------------------------------------------------------------
                                                                  Configuration
           Parameter            --------------------------------------------------------------------------------
                                    1        2        3        4        5        6        7      . . .      n
----------------------------------------------------------------------------------------------------------------
mfuel[cycle]...................
fpowertrain[cycle].............
Tpowertrain[cycle].............
W[cycle].......................
----------------------------------------------------------------------------------------------------------------

    (p) Determining useable battery energy. Useable battery energy
(UBE) is defined as the total DC discharge energy,
EDCDtotal, measured in DC Watt hours, over the charge-
depleting portion of the test sequence determined in paragraph (p)(2)
of this section for the Heavy-duty Transient Test Cycle in 40 CFR part
1037, appendix A. Select a representative vehicle configuration from
paragraph (h) of this section for determination of UBE. UBE represents
the total deliverable energy the battery is capable of providing while
a powertrain is following a duty cycle on a dynamometer.
    (1) Measure DC discharge energy, EDCD, in watt-hours and
DC discharge current per hour, CD, for the charge-depleting
portion of the test sequence. The measurement points must capture all
the current flowing into and out of the battery pack during powertrain
operation, including current associated with regenerative braking. The
equation for calculating powertrain EDCD is given in Eq.
1036.545-12, however, it is expected that this calculation will
typically be performed internally by the power analyzer specified in
paragraph (a)(10)(i) of this section. Battery voltage measurements made
by the powertrain's own on-board sensors (such as those available via a
diagnostic port) may be used for calculating EDCD if these measurements
are equivalent to those produced by the power analyzer.
[GRAPHIC] [TIFF OMITTED] TP27AP23.067

Where:

i = an indexing variable that represents one individual measurement.
N = total number of measurements.
V = battery DC bus voltage.
I = battery current.
[Delta]t = 1/frecord
frecord = the data recording frequency.

Example:

N = 13360
V1 = 454.0
V2 = 454.0
I1 = 0
I2 = 0
frecord = 20 Hz
[Delta]t = 1/20 = 0.05 s
[GRAPHIC] [TIFF OMITTED] TP27AP23.068

EDCD = 6540232.7 W[middot]s = 1816.7 W[middot]hr

    (2) Determine a declared UBE that is at or below the corresponding
value determined in paragraph (p)(1) of this section, including those
from redundant measurements. This declared UBE serves as the initial
UBE determined under 40 CFR 1037.115(f).
0
30. Amend Sec.  1036.550 by revising paragraphs (b)(1)(i), (b)(2)
introductory text, and (b)(2)(i) to read as follows:

Sec.  1036.550  Calculating greenhouse gas emission rates.

* * * * *
    (b) * * *
    (1) * * *
    (i) For liquid fuels, determine Emfuelmeas according to
ASTM D4809 (incorporated by reference, see Sec.  1036.810). Have the
sample analyzed by at least three different labs and determine the
final value of your test fuel's Emfuelmeas as the median of
all the lab test results you obtained as described in 40 CFR
1065.602(m). If you have results from three different labs, we
recommend you screen them to

determine if additional observations are needed. To perform this
screening, determine the absolute value of the difference between each
lab result and the average of the other two lab results. If the largest
of these three resulting absolute value differences is greater than
0.297 MJ/kg, we recommend you obtain additional results prior to
determining the final value of Emfuelmeas.
* * * * *
    (2) Determine your test fuel's carbon mass fraction, wC,
as described in 40 CFR 1065.655(d), expressed to at least three decimal
places; however, you must measure fuel properties for [alpha] and
[beta] rather than using the default values specified in 40 CFR
1065.655(e).
    (i) For liquid fuels, have the sample analyzed by at least three
different labs and determine the final value of your test fuel's
wC as the median of all of the lab results you obtained as
described in 40 CFR 1065.602(m). If you have results from three
different labs, we recommend you screen them to determine if additional
observations are needed. To perform this screening, determine the
absolute value of the difference between each lab result and the
average of the other two lab results. If the largest of these three
resulting absolute value differences is greater than 1.56 percent
carbon, we recommend you obtain additional results prior to determining
the final value of wC.
* * * * *
0
31. Amend Sec.  1036.605 by revising paragraph (e) to read as follows:

Sec.  1036.605  Alternate emission standards for engines used in
specialty vehicles.

* * * * *
    (e) In a separate application for a certificate of conformity,
identify the corresponding nonroad engine family, describe the label
required under section, state that you meet applicable diagnostic
requirements under 40 CFR part 1039 or part 1048, and identify your
projected U.S.-directed production volume.
* * * * *
0
32. Amend Sec.  1036.615 by revising paragraph (a) to read as follows:

Sec.  1036.615  Engines with Rankine cycle waste heat recovery and
hybrid powertrains.

* * * * *
    (a) Pre-transmission hybrid powertrains. Test pre-transmission
hybrid powertrains with the hybrid engine procedures of 40 CFR part
1065 or with the post-transmission procedures in Sec.  1036.545. Pre-
transmission hybrid powertrains are those engine systems that include
features to recover and store energy during engine motoring operation
but not from the vehicle's wheels. Engines certified with pre-
transmission hybrid powertrains must be certified to meet the
diagnostic requirements as specified in Sec.  1036.110 with respect to
powertrain components and systems; if different manufacturers produce
the engine and the hybrid powertrain, the hybrid powertrain
manufacturer may separately certify its powertrain relative to
diagnostic requirements.
* * * * *
0
33. Amend Sec.  1036.630 by revising paragraph (b) to read as follows:

Sec.  1036.630  Certification of engine greenhouse gas emissions for
powertrain testing.

* * * * *
    (b) If you choose to certify only fuel map emissions for an engine
family and to not certify emissions over powertrain cycles under Sec.
1036.545, we will not presume you are responsible for emissions over
the powertrain cycles. However, where we determine that you are
responsible in whole or in part for the emission exceedance in such
cases, we may require that you participate in any recall of the
affected vehicles. Note that this provision to limit your
responsibility does not apply if you also hold the certificate of
conformity for the vehicle.
* * * * *
0
34. Amend Sec.  1036.705 by revising paragraph (c) introductory text,
redesignating paragraph (c)(4) as paragraph (c)(5), and adding a new
paragraph (c)(4) to read as follows:

Sec.  1036.705  Generating and calculating emission credits.

* * * * *
    (c) Compliance with the requirements of this subpart is determined
at the end of the model year by calculating emission credits based on
actual production volumes, excluding the following engines:
* * * * *
    (4) Engines certified to state emission standards that are
different than the emission standards in this part.
* * * * *
0
35. Amend Sec.  1036.725 by revising paragraph (b)(2) to read as
follows:

Sec.  1036.725  Required information for certification.

* * * * *
    (b) * * *
    (2) Calculations of projected emission credits (positive or
negative) based on projected production volumes as described in Sec.
1036.705(c). We may require you to include similar calculations from
your other engine families to project your net credit balances for the
model year. If you project negative emission credits for a family,
state the source of positive emission credits you expect to use to
offset the negative emission credits.
0
36. Amend Sec.  1036.730 by revising paragraphs (b)(4) and (f)(1) to
read as follows:

Sec.  1036.730  ABT reports.

* * * * *
    (b) * * *
    (4) The projected and actual production volumes for calculating
emission credits for the model year. If you changed an FEL/FCL during
the model year, identify the actual production volume associated with
each FEL/FCL.
* * * * *
    (f) * * *
    (1) If you notify us by the deadline for submitting the final
report that errors mistakenly decreased your balance of emission
credits, you may correct the errors and recalculate the balance of
emission credits. If you notify us that errors mistakenly decreased
your balance of emission credits after the deadline for submitting the
final report, you may correct the errors and recalculate the balance of
emission credits after applying a 10 percent discount to the credit
correction, but only if you notify us within 24 months after the
deadline for submitting the final report. If you report a negative
balance of emission credits, we may disallow corrections under this
paragraph (f)(1).
* * * * *
0
37. Amend Sec.  1036.735 by revising paragraph (d) to read as follows:

Sec.  1036.735  Recordkeeping.

* * * * *
    (d) Keep appropriate records to document production volumes of
engines that generate or use emission credits under the ABT program.
For example, keep available records of the engine identification number
(usually the serial number) for each engine you produce that generates
or uses emission credits. You may identify these numbers as a range. If
you change the FEL/FCL after the start of production, identify the date
you started using each FEL/FCL and the range of engine identification
numbers associated with each FEL/FCL. You must also identify the
purchaser and destination for each engine you produce to the extent
this information is available.
* * * * *
0
38. Amend Sec.  1036.801 by:

0
a. Adding a definition of ``Carbon-containing fuel'' in alphabetical
order.
0
b. Removing the definitions of ``Criteria pollutants'' and ``Greenhouse
gas''.
0
c. Revising the definition of ``Hybrid''.
0
d. Removing the definitions of ``Hybrid engine'' and ``Hybrid
powertrain''.
0
e. Revising the definition of ``Mild hybrid''.
0
f. Adding a definition of ``Neat'' in alphabetical order.
0
g. Revising the definitions of ``Small manufacturer'' and ``U.S.-
directed production volume''.

    The additions and revisions read as follows:

Sec.  1036.801  Definitions.

* * * * *
    Carbon-containing fuel has the meaning given in 40 CFR 1065.1001.
* * * * *
    Hybrid means relating to an engine or powertrain that includes a
Rechargeable Energy Storage System. Hybrid engines store and recover
energy in a way that is integral to the engine or otherwise upstream of
the vehicle's transmission. Examples of hybrid engines include engines
with hybrid components connected to the front end of the engine (P0),
at the crankshaft before the clutch (P1), or connected between the
clutch and the transmission where the clutch upstream of the hybrid
feature is in addition to the transmission clutch(s) (P2). Engine-based
systems that recover kinetic energy to power an electric heater in the
aftertreatment are themselves not sufficient to qualify as a hybrid
engine. Provisions that apply for hybrid powertrains apply equally for
hybrid engines, except as specified. Note that certain provisions in
this part treat hybrid powertrains intended for vehicles that include
regenerative braking different than those intended for vehicles that do
not include regenerative braking. The definition of hybrid includes
plug-in hybrid electric powertrains.
* * * * *
    Mild hybrid means relating to a hybrid engine or hybrid powertrain
with regenerative braking capability where the system recovers less
than 20 percent of the total braking energy over the transient cycle
defined in appendix A of 40 CFR part 1037.
* * * * *
    Neat has the meaning given in Sec.  1065.1001.
* * * * *
    Small manufacturer means a manufacturer meeting the criteria
specified in 13 CFR 121.201. The employee and revenue limits apply to
the total number of employees and total revenue together for all
affiliated companies (as defined in 40 CFR 1068.30). Note that
manufacturers with low production volumes may or may not be ``small
manufacturers''.
* * * * *
    U.S.-directed production volume means the number of engines,
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. Note that
this includes engines certified to state emission standards that are
different than the emission standards in this part.
* * * * *
0
39. Amend Sec.  1036.805 by adding an entry for ``GCWR'' to Table 5 in
alphabetical order to read as follows:

Sec.  1036.805  Symbols, abbreviations, and acronyms.

* * * * *
    (e) * * *

     Table 5 to Paragraph (e) of Sec.   1036.805--Other Acronyms and
                              Abbreviations
------------------------------------------------------------------------
                  Acronym                              Meaning
------------------------------------------------------------------------

                                * * * * *
GCWR......................................  gross combined weight
                                             rating.

                                * * * * *
------------------------------------------------------------------------

* * * * *
0
40. Amend Sec.  1036.810 by adding paragraph (e) to read as follows:

Sec.  1036.810  Incorporation by reference.

* * * * *
    (e) U.S. EPA, Office of Air and Radiation, 2565 Plymouth Road, Ann
Arbor, MI 48105; www.epa.gov; [email protected].
    (1) Greenhouse gas Emissions Model (GEM) Phase 2, Version 4.0,
April 2022 (``GEM Phase 2, Version 4.0''); IBR approved for Sec.
1036.545(a).
    (2) [Reserved]
0
41. Amend Sec.  1036.815 by revising paragraph (b) to read as follows:

Sec.  1036.815  Confidential information.

* * * * *
    (b) Emission data or information that is publicly available cannot
be treated as confidential business information as described in 40 CFR
1068.11. Data that vehicle manufacturers need for demonstrating
compliance with greenhouse gas emission standards, including fuel-
consumption data as described in Sec. Sec.  1036.535 and 1036.545, also
qualify as emission data for purposes of confidentiality
determinations.

PART 1037--CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES

0
42. The authority citation for part 1037 continues to read as follows:

    Authority:  42 U.S.C. 7401-7671q.

0
43. Amend Sec.  1037.1 by revising paragraph (a) to read as follows:

Sec.  1037.1  Applicability.

    (a) The regulations in this part 1037 apply for all new heavy-duty
vehicles, except as provided in Sec.  1037.5. This includes battery
electric vehicles, fuel cell electric vehicles, and vehicles fueled by
conventional and alternative fuels.
* * * * *
0
44. Amend Sec.  1037.5 by:
0
a. Revising paragraph (e).
0
b. Removing paragraphs (g) and (h).
0
c. Redesignating paragraph (i) as paragraph (g).
    The revision reads as follows:

Sec.  1037.5  Excluded vehicles.

* * * * *
    (e) Vehicles subject to the heavy-duty emission standards of 40 CFR
part 86. See 40 CFR part 86, subpart S, for emission standards that
apply for these vehicles.
* * * * *
0
45. Amend Sec.  1037.101 by revising paragraphs (a)(2) and (b)(2) and
(3) to read as follows:

Sec.  1037.101  Overview of emission standards.

* * * * *
    (a) * * *
    (2) Exhaust emissions of greenhouse gases. Emission standards apply
as follows for greenhouse gas emissions:
    (i) CO2 emission standards apply as described in
Sec. Sec.  1037.105 and 1037.106. No CH4 or N2O
standards apply under this part. See 40 CFR part 1036 for
CH4 or N2O standards that apply to engines used
in these vehicles.
    (ii) Hydrofluorocarbon standards apply as described in Sec.
1037.115(e). These pollutants are also ``greenhouse gas pollutants''
but are treated separately from exhaust greenhouse gas pollutants
listed in paragraph (a)(2)(i) of this section.
* * * * *
    (b) * * *
    (2) For greenhouse gas pollutants, vehicles are regulated in the
following groups:

    (i) Tractors above 26,000 pounds GVWR.
    (ii) Vocational vehicles.
    (3) The greenhouse gas emission standards apply differently
depending on the vehicle service class as described in Sec.  1037.140.
In addition, standards apply differently for vehicles with spark-
ignition and compression-ignition engines. References in this part 1037
to ``spark-ignition'' or ``compression-ignition'' generally relate to
the application of standards under 40 CFR 1036.140. For example, a
vehicle with an engine certified to spark-ignition standards under 40
CFR part 1036 is generally subject to requirements under this part 1037
that apply for spark-ignition vehicles. However, note that emission
standards for Heavy HDE are considered to be compression-ignition
standards for purposes of applying vehicle emission standards under
this part. Also, for spark-ignition engines voluntarily certified as
compression-ignition engines under 40 CFR part 1036, you must choose at
certification whether your vehicles are subject to spark-ignition
standards or compression-ignition standards. Heavy-duty vehicles with
no installed propulsion engine, such as battery electric vehicles, are
subject to compression-ignition emission standards for the purpose of
calculating emission credits.
* * * * *
0
46. Amend Sec.  1037.102 by revising the section heading and paragraph
(b) introductory text to read as follows:

Sec.  1037.102  Criteria exhaust emission standards--NOX, HC, PM, and
CO.

* * * * *
    (b) Heavy-duty vehicles with no installed propulsion engine, such
as battery electric vehicles, are subject to criteria pollutant
standards under this part. The emission standards that apply are the
same as the standards that apply for compression-ignition engines under
40 CFR 86.007-11 and 1036.104 for a given model year.
* * * * *
0
47. Amend Sec.  1037.105 by:
0
a. Revising paragraphs (a)(1) and (2) and (b)(1) and (4)
0
b. Removing and reserving paragraph (c).
0
c. Revising paragraph (h)(1).
    The revisions read as follows:

Sec.  1037.105  CO2 emission standards for vocational vehicles.

    (a) * * *
    (1) Heavy-duty vehicles at or below 14,000 pounds GVWR that are not
subject to the greenhouse gas standards in 40 CFR part 86, subpart S,
or that use engines certified under Sec.  1037.150(m).
    (2) Vehicles above 14,000 pounds GVWR and at or below 26,000 pounds
GVWR, but not certified to the vehicle greenhouse gas standards in 40
CFR part 86, subpart S.
* * * * *
    (b) * * *
    (1) Model year 2027 and later vehicles are subject to
CO2 standards corresponding to the selected subcategories as
shown in the following table:

                 Table 1 of Paragraph (b)(1) of Sec.   1037.105--Phase 3 CO2 Standards for Model Year 2027 and Later Vocational Vehicles
                                                                      [g/ton-mile]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Compression-ignition engine                Spark-ignition engine
                Model year                           Subcategory         -------------------------------------------------------------------------------
                                                                             Light HDV      Medium HDV       Heavy HDV       Light HDV      Medium HDV
--------------------------------------------------------------------------------------------------------------------------------------------------------
2027......................................  Urban.......................             294             213             232             340             252
                                            Multi-Purpose...............             257             190             193             299             223
                                            Regional....................             218             173             152             246             202
2028......................................  Urban.......................             275             209             228             321             248
                                            Multi-Purpose...............             238             186             189             280             219
                                            Regional....................             199             169             148             227             198
2029......................................  Urban.......................             255             202             225             301             241
                                            Multi-Purpose...............             218             179             186             260             212
                                            Regional....................             179             162             145             207             191
2030......................................  Urban.......................             238             195             200             284             234
                                            Multi-Purpose...............             201             172             161             243             205
                                            Regional....................             162             155             120             190             184
2031......................................  Urban.......................             219             188             193             265             227
                                            Multi-Purpose...............             182             165             154             224             198
                                            Regional....................             143             148             113             171             177
2032 and later............................  Urban.......................             179             176             177             225             215
                                            Multi-Purpose...............             142             153             138             184             186
                                            Regional....................             103             136              97             131             165
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (4) Model year 2014 through 2020 vehicles are subject to Phase 1
CO2 standards as shown in the following table:

                 Table 4 of Paragraph (b)(4) Sec.   1037.105--Phase 1 CO2 Standards for Model Year 2014 Through 2020 Vocational Vehicles
                                                                      [g/ton-mile]
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Vehicle size                       CO2 standard for model years 2014-2016                     CO2 standard for model year 2017-2020
--------------------------------------------------------------------------------------------------------------------------------------------------------
Light HDV...........................                                                       388                                                       373