Revised 2023 and Later Model Year
Light-Duty Vehicle Greenhouse Gets
Emissions Standards
Regulatory Update
United States
Environmental Protection
hI M »Agency
EPA-420-F-21-077
December 2021

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Revised 2023 and Later Model Year Light-Duty Vehicle Greenhouse Gas
Emissions Standards - Final Rule
The Environmental Protection Agency (EPA) is finalizing federal greenhouse gas (GHG) emissions
standards for passenger cars and light trucks by setting ambitious but achievable requirements for
emissions reductions for Model Years (MY) 2023 through 2026. The standards would achieve significant
GHG emissions reductions along with reductions in other air pollutants. This rule will result in
substantial public health and welfare benefits, while providing fuel savings to consumers. Today's action
will set the U.S. on a course to achieve ambitious GHG emissions reductions from transportation over
the long term. The final rule provides a foundation for building on rapidly developing trends toward
zero-emission technologies and the substantial reductions in air pollution they will make possible.
As a follow on to this action, EPA plans to initiate a future rulemaking to establish multi-pollutant
emission standards for MY 2027 and beyond. Consistent with the direction of Executive Order 14037,
"Strengthening American Leadership in Clean Cars and Trucks," this subsequent rulemaking will set
standards through at least MY 2030 and will apply to light-duty vehicles and medium-duty vehicles.1
Setting the Program on a Trajectory to Achieve Significant GHG Reductions
Today's rule puts EPA's clean cars program on track to achieve significant GHG emissions reductions
over the long term. The final rule will prompt automakers to use clean technologies that are available
today and help stimulate production of more electric vehicles. This rule is a critical step to setting the
U.S. on a path to a zero-emissions transportation future.
The final rule revises current GHG standards beginning in MY 2023 and increases in stringency year over-
year through MY 2026. The standards finalized for MYs 2025 and 2026 are the most stringent option
considered in the proposed rule and the MY 2026 requirements establish the most stringent GHG
standards ever set for the light-duty vehicle sector. The final rule significantly accelerates the rate of
stringency increases to between 5 and 10 percent each year from 2023 through 2026. Under the
previous standards stringency increased at a rate of roughly 1.5 percent per year. Today's final
standards are expected to result in average fuel economy label values of 40 mpg, while the standards
they replace (the SAFE rule standards) would achieve only 32 mpg in MY2026.
1 Medium duty vehicles include commercial pickups and vans, also referred to as heavy-duty class 2b and 3
vehicles.

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Table 1: Comparison of Fleet Average Target Projections for the Final Standards Compared to Updated
Fleet Average Target Projections* for the Proposed Standards, SAFE Rule and 2012 Rule

EPA Projected Fleet-
EPA C02 standards
EPA Estimated Real

wide C02 Emissions
expressed as "MPG
World Label Value***

Standards
equivalent"**

MY 2026 Standard
161 grams/mile
55 mpg
40 mpg
Projections: Final Rule



MY 2026 Standard
173 grams/mile
52 mpg
38 mpg
Projections: Proposal



MY 2026 Standards:
208 grams/mile
43 mpg
32 mpg
2020 Final Rule (SAFE2)



MY 2025 Standards:
180 grams/mile
50 mpg
36 mpg
2012 Final Rule



* All values calculated using the final rule updated fleet mix of 47% cars and 53% trucks in MY2026.
**MPG equivalent is the MPG assuming the GHG standards are met exclusively by reducing tailpipe CO2.
***This is a value that would be comparable to what a consumer would see on a fuel economy label and reflects
real-world impacts on GHG emissions and fuel economy that are not captured by the compliance tests, including
high speed driving, air conditioning usage, and cold temperatures.
Climate Urgency
Making cars cleaner is critical to address climate change. Transportation is the single largest source of
GHG emissions in the United States, making up 29 percent of all emissions. Within the transportation
sector, passenger cars and trucks are the largest contributor, at 58 percent of all transportation sources
and 17 percent of total U.S. GHG emissions.
The final standards will contribute toward the goal of holding the increase in the global average
temperature to well below 2°C above pre-industrial levels and reducing the probability of severe climate
change-related impacts, including heat waves, drought, sea level rise, extreme climate and weather
events, coastal flooding, and wildfires. Reductions in GHG emissions from this rule will benefit
populations that may be especially vulnerable to damages associated with climate change, such as the
very young, the elderly, communities of color, low-income, disabled, and indigenous populations.
Benefits
This final rule would provide significant benefits with respect emission reductions, public health, and
fuel savings.
• The benefits of this rule exceed the costs by $120 billion to $190 billion through 2050. Benefits
include reduced impacts of climate change, improved public health from lower pollution, and
cost savings for vehicle owners through improved fuel efficiency.

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•	Between $8 and $19 billion of the total benefits through 2050 result from improved public
health due to reduced emissions of non-GHG pollutants, including NOx and other pollutants that
contribute to fine particulates (PM2.5).
•	Looking at fuel costs alone, American drivers will save between $210 billion and $420 billion
through 2050.
Consumer Savings
Consumers will benefit from EPA's final standards due to savings from reduced fuel costs. EPA estimates
that reduced fuel costs will outweigh the increase in vehicle costs by about $1,080 over the lifetime of a
MY 2026 vehicle. In other words, lifetime fuel savings will outweigh the upfront vehicle cost, and fuel
savings accumulate over time, with savings growing relative to costs.
Emissions Standards
As with EPA's previous light-duty GHG programs, EPA is finalizing standards expressed as "footprint
based curves" for both passenger cars and trucks. Under this approach, each manufacturer has a unique
standard for the passenger car and truck categories, for each model year, based on the sales-weighted
footprint-based C02 targets of the vehicles produced in each MY.
The graphic below (Figure 1) shows EPA's final standards, expressed as average fleetwide GHG emissions
targets (cars and trucks combined), projected through MY 2026. For comparison, the figure also shows
the corresponding targets for the proposal and the prior 2020 and 2012 rules. The projected fleet
targets under the final rule increase in stringency in MY 2023 by about 10 percent (from the existing
standards in MY 2022), followed by a stringency increase of about 5 percent in MY 2024, as proposed.
For MYs 2025-2026 EPA is finalizing stringency increases more stringent than those proposed, about 7
and 10 percent year over year, respectively. EPA intends to initiate a subsequent rule to establish
standards for MYs 2027 and beyond.

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200

	Safe
	2012frm
	Proposal
140
2020 2021 2022 2023 2024 2025 2026 2027
Model Year
Figure 1: EPA Final Industry Fleet-Wide C02 Compliance Targets, Compared to the Proposal and 2012
and 2020 Rules, grams/mile, 2021-2026
Table 1 (below) presents the estimates of EPA's final standards presented in Figure 1, in terms of the
projected overall industry fleetwide C02-equivalent emission compliance target levels. The industry
fleet wide estimates in Table 1 are projections based on modeling EPA conducted for the final rule,
taking into consideration projected fleet mix and footprints for each manufacturer's fleet in each model
year. Table 2 presents projected industry fleet average year-over-year percent C02 reductions for the
final standards. Table 3 presents projected technology penetration levels in MY 2026 for several major
technology categories.
Table 1: Projected Industry Fleet-wide C02 Compliance Targets (C02 grams/mi)
Model Year
Cars
Trucks
Combined Fleet
2022 (SAFE
reference)
181
261
224
2023
166
234
202
2024
158
222
192
2025
149
207
179
2026 and later
132
187
161

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Table 2: Projected Industry Fleet Average C02 Target Year-Over-Year Percent Reductions
Model Year
Combined Fleet
2023
9.8%
2024
5.1%
2025
6.6%
2026
10.3%
Cumulative
28.3%
Table 3: Model Year 2026 Technology Penetrations Projected under the Final Rule
Technology
New Light-duty Vehicle Fleet
Penetration
Advanced High-efficiency Engine Technology
59%
8-speed and other advanced transmissions
71%
Mild Hybrid
5%
Strong Hybrid
7%
Battery Electric Vehicles + Plug-in Hybrid Electric Vehicles
17%
Achievable Efficiency Gains, Building on Sector Trends
Automakers are in a strong position to meet these final standards. The auto industry supported EPA's
proposal for the standards to begin in MY2023, and our final rule maintains the MY2023 start date for
revised standards. From 2012 until last year, all the automakers were required to meet more stringent
standards in 2023 than those being finalized today. Their technological progress over the years has
been impressive. Although the 2020 SAFE rule standards were much less stringent, technological
advancement over the past ten years has been significant and continues. Nearly all major automakers
have announced plans to transition their vehicle fleets to zero-emissions, with many electric vehicle
launches planned before 2026. The entry of so many new EV models over the next few years will put
the auto industry in a strong position to meet the standards. Finally, the program includes averaging,
credit banking and trading provisions to aid the industry in meeting standards through a multi-year
planning process, and EPA also is finalizing additional targeted compliance flexibilities to help the
industry manage its transition to more stringent standards.
Program Flexibilities and Incentives
EPA's regulatory programs for cars and trucks have traditionally offered automakers compliance options
to help them meet standards in the ways that are most appropriate and cost effective for individual
companies. EPA received many comments on the proposed flexibility provisions of this rule. After
considering the comments along with our updated analyses, we are finalizing flexibility provisions that
are narrower than proposed. The final rule focuses the available flexibilities in MYs 2023-2024 to help
manufacturers manage the transition to more stringent standards in the longer term by providing some
additional flexibility in the near-term. The flexibilities that EPA is adopting are:
• A limited extension of credits generated by overcompliance with the MYs 2017 and 2018
standards that can be carried forward for compliance with the MY 2023-2024 standards,
respectively.

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•	Advanced technology vehicle multiplier credits for MYs 2023-2024 with a cumulative credit cap
of 10 grams C02 per mile. This incentive encourages manufacturers to accelerate introduction
of zero and near-zero emissions vehicles.
•	Full-size pickup truck incentives for strong hybrids or similar performance-based credit for MYs
2023-2024. Similar incentives were included in the 2012 rule but removed by the 2020 SAFE
rule for MYs 2022-2025.
•	"Off-cycle" credits of up to 15 g/mile. Off-cycle credits recognize and incentivize technologies
that provide real-world emissions reductions but which are not captured on EPA's tailpipe
emissions compliance tests. These include technologies such as high-efficiency headlamps or
solar reflective paint that keeps the vehicle cabin cooler to reduce air conditioning needs.
Safety
This rule will not impact driving safety. EPA estimates that the risk of fatal and non-fatal injuries will
remain virtually unchanged by this program.

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