Multi-Pollutant Emissions Standards
for Model Years 2027 and Later
Light-Duty and Medium-Duty Vehicles
t:
he U.S. Environmental Protection Agency (EPA) is proposing new
and stronger standards to further reduce harmful air pollutant
emissions from light-duty and medium-duty vehicles (also known as
Class 2b and 3 vehicles) starting with model year (MY) 2027. The
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electrification. These developments in the U.S. and around the world demonstrate that proven,
zero-emission technology is an available and feasible way to greatly reduce emissions of both
greenhouse gases and criteria pollutants and is capable of being implemented across a large portion
of the new vehicle fleet.
In addition, the Bipartisan Infrastructure Law and the Inflation Reduction Act provide
unprecedented investment to accelerate the development of and market for zero-emission
technology. These measures provide significant support for expanding the manufacture, sale,
and use of zero-emission vehicles by addressing elements critical to the advancement of clean
transportation and clean electricity generation.
In assessing the feasibility of the proposed standards, EPA has considered current and anticipated
progress by automakers in developing and deploying a diverse range of technologies. The proposed
levels of stringency would continue the trend adopted by prior EPA rules of increasing the
stringency of emission standards to achieve additional emissions reductions. While advanced
gasoline technologies are expected to continue to play an important role in the future, vehicle
electrification technologies enable significant additional emissions reductions.
As the EPA greenhouse gas standards have increased in stringency, automakers have introduced
a wider range of electrification technologies, including hybrid electric vehicles (HEVs) and, in
recent years, plug-in hybrid electric vehicles (PHEVs) and battery-electric vehicles (BEVs). EPA
anticipates that manufacturers would continue to employ a diverse range of technologies to comply
with the proposed emissions standards, but also recognizes that manufacturer investment and
consumer interest in electric vehicles is growing. Automakers are including electrified vehicles as
an increasingly integral part of their current and future product lines, leading to an increasing
diversity of, and demand for, these clean vehicles.
The Proposed Standards - Greenhouse Gas Emissions Standards
EPA is proposing more stringent greenhouse gas standards for both light-duty vehicles and
medium-duty vehicles for MYs 2027 through 2032. In addition to the proposed standards, EPA
is seeking comment on three alternative levels of stringency, and on the range of standards across
these alternatives and the proposal, and also on whether the standards should continue to increase
in stringency for future years, such as through MY 2035.
For light-duty vehicles, EPA is proposing standards that would increase in stringency each year
over a six-year period, from MYs 2027-2032. The proposed standards are projected to result in
an industry-wide average target for the light-duty fleet of 82 grams/mile (g/mile) of CO 2 in MY
2032, representing a 56 percent reduction in projected fleet average greenhouse gas emissions
target levels relative to the existing MY 2026 standards. The projected industry fleet average g/mile
targets under the proposed MY 2027-203 2 standards compared to the current MY 2026 standard
(established in 2021) are shown in the figure below.
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200
180
160
140
120
I
100
W)
80
60
40
20
0
2026 2027 2028 2029 2030
Model Year
2031
2032
2021 Rule
Alternative 2
Proposal
•Alternative 3
Alternative 1
For medium-duty vehicles, EPA is proposing to revise the existing standards for MY 2027 given the
increased feasibility of greenhouse gas emissions reducing technologies in this sector in this time
frame. EPA's proposed standards for MDVs would increase in stringency year over year from MY
2027 through MY 2032. When phased in, the MDV standards are projected to result in an average
target of 275 grams/mile of CO 2 by MY 2032, which would represent a reduction of 44 percent
in projected fleet average greenhouse gas emissions target levels relative to the current MY 2026
standards. The projected targets for medium-duty vans and pickups and the combined medium-
duty fleet are provided in the table below.
Model Year
Combined
Vans
C02 (g/mile)
Pickups
C02 (g/mile)
Combined
C02 (g/mile)
2027
393
462
438
2028
379
452
427
2029
345
413
389
2030
309
374
352
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Model Year
Combined
Vans
C02 (g/mile)
Pickups
C02 (g/mile)
Combined
C02 (g/mile)
2031
276
331
312
2032 and later
243
292
275
The Proposed Standards - Criteria Pollutant Emissions Standards
For light-duty vehicles, EPA is proposing non-methane organic gases (NMOG) plus nitrogen
oxides (NOx) standards that would phase-down to a fleet average level of 12 mg/mi by MY
2032, representing a 60 percent reduction from the existing 30 mg/mi standards for MY 2025
established in the Tier 3 rule in 2014. For MDVs, EPA is proposing NMOG+NOx standards
that would require a fleet average level of 60 mg/mi by MY 203 2, representing a 66 percent to
76 percent reduction from the Tier 3 standards of 178 mg/mi for 2b vehicles and 247 mg/mi
for class 3 vehicles. EPA is proposing cold temperature (-7°C) NMOG+NOx standards for light-
and medium-duty vehicles to ensure robust emissions control over a broad range of operating
conditions. The proposed standards would also reduce emissions of mobile source air toxics. Once
phased into the Tier 4 program, vehicles would be required to meet the proposed fleet average
standards shown below.
Model Year
LDVs
MDV* NMOG+NOx (mg/mi)
Class 2b
Class 3
2026
30*
178*
247*
2027
22
160
2028
20
140
2029
18
120
2030
16
100
2031
14
80
2032 and later
12
60
*Tier 3 standards provided for reference
t NMOG+NOx credit generated underTier 3 can be carried forward for 5 years after it is generated. MDV
standards only apply for vehicles under 22,000 lb GCWR.
The NMOG+NOx standards continue the emissions certification "bin" structure approach EPA has
successfully used in prior criteria pollutant programs. Manufacturers assign each vehicle model to a
bin that includes the applicable NMOG+NOx standards. EPA is proposing that manufacturers would
be required to meet the standards across several test cycles. The proposed Tier 4 bins are as follows:
LDV bin
NMOG+NOx (mg/mi)
Bin 160*
160
Bin 125*
125
Bin 70
70
Bin 60
60
Bin 50
50
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LDV bin
NMOG+NOx (mg/mi)
Bin 40
40
Bin 30
30
Bin 20
20
Bin 10
10
Bin 0
0
* MDV only
For both light-duty and medium-duty vehicles, EPA is proposing a Tier 4 PM standard of 0.5
mg/mi and a requirement that the standard be met across three test cycles, including a cold
temperature (-7°C) test to ensure robust emissions control across a range of in-use driving
conditions.
Projected Mix of Technologies
The proposed standards are performance-based, allowing each automaker to choose what set of
emissions control technologies is best suited for their vehicle fleet to meet the standards. EPA
projects that one potential pathway for the industry to meet the proposed standards would be
through:
• Nearly 70 percent BEV penetration in MY 2032 across the combined light-duty passenger car,
crossover/SUV, and pickup truck categories
• About 40 percent BEV penetration by 2032 across the combined medium-duty van and pickup
truck categories
• Wide-spread use of gasoline particulate filters to reduce PM emissions
• Improvements in technology to reduce CO 2 from conventional gasoline vehicles
Manufacturers may also choose to employ hybrid or plug-in hybrid technologies to help meet the
proposed standards.
Climate and Air Quality Urgency
Making cars cleaner is critical to address climate change and improve air quality. Transportation is
the single largest source of greenhouse gas emissions in the United States, making up 27 percent
of total greenhouse gas 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.
greenhouse gas emissions.
The proposed standards would 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 greenhouse gas emissions from
this proposal would 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.
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EPA's proposal would significantly reduce emissions of air pollutants that contribute to climate
change and unhealthy air. Between 2027 and 2055, the proposed standards would cumulatively
avoid 7.3 billion metric tons of C02. In 2055, the proposal would reduce harmful air pollutants
from vehicles, including approximately 15,000 tons of PM2.5, 66,000 tons of NOx, and 220,000
tons of hydrocarbons, compared to 2055 levels without the proposal. These pollutants contribute
to the formation of PM ("soot") and ozone ("smog"), as well as elevated concentrations of pollution
near roadways, where millions of people live and people of color and people with low income are
disproportionately exposed to air pollution from vehicles.
Benefits
EPA estimates that the total benefits of this proposal far exceed the total costs, with net present
value of benefits in the range of range of $850 billion to $1.6 trillion, with equivalent annualized
net benefits in the range of $60 billion to $85 billion.
Between $63 billion and $280 billion of total benefits are attributable to reduced emissions of
criteria pollutants that contribute to ambient concentrations of PM2.5. PM2.5 is associated with
premature death and serious health effects such as hospital admissions due to respiratory and
cardiovascular illnesses, nonfatal heart attacks, aggravated asthma, and decreased lung function.
The proposed program is estimated to have $330 billion in climate benefits.
Costs and Consumer Savings
The vehicle technology costs of this proposal range from $180 billion to $280 billion, but the
program also would have additional social benefits from fuel savings of $450 billion to $890 billion
through 2055, and repair and maintenance savings (stemming from lower maintenance and repair
of electric vehicles compared to gasoline vehicles) estimated through 2055 at $280 billion to
$580 billion.
EPA estimates that the standards will increase the technology costs to auto manufacturers by about
$ 1,200 per vehicle on average in model year 2032. This estimate represents compliance costs
to the industry and is not the same as the price consumers pay when purchasing a new vehicle.
For example, purchase price could be reduced by any state and Federal purchase incentives that
are available to consumers. Under the Inflation Reduction Act, consumers are eligible for up to
$7,500 for the purchase of an electric vehicle.
In addition, consumers would benefit from significant savings on operating costs over the life of
a vehicle that meets the proposed standards. For all vehicles meeting the standards, these savings
include fuel savings and, for BEVs, maintenance and repair savings as well. Although EPA cannot
predict how an individual manufacturer will price vehicles, we project that the average increase
in the technology costs of a new vehicle will be more than fully offset by significant savings in
operating costs.
For example, a BEV owner of a model year 2032 sedan, crossover, or SUV would save more than
$9,000 on average on fuel, maintenance, and repair costs over an eight-year period (the average
period of first ownership) compared to a gasoline vehicle. A BEV pickup truck owner would save
even more - about $13,000.
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Additional Provisions
In addition, EPA is proposing greenhouse gas program revisions in several areas, including off-cycle
and air conditioning credits, the treatment of upstream emissions associated with battery-electric and
plug-in hybrid electric vehicles in compliance calculations, and vehicle certification and compliance.
EPA is proposing battery durability and warranty requirements for light- and medium-duty plug-in
vehicles, and new standards to control refueling emissions from incomplete medium-duty vehicles.
EPA is proposing revised small volume manufacturer provisions that are available to manufacturers of
less than 5,000 vehicles per year. EPA is also proposing additional flexibilities for small businesses.
EPA is also seeking comment on potential future gasoline fuel property standards, aimed at further
reducing PM emissions, for consideration in a possible subsequent rulemaking. These could
provide an important complement to the vehicle standards being proposed in the current action.
Public Participation
EPA welcomes public input into this rulemaking and looks forward to continuing its engagement
with stakeholders throughout the rulemaking process. Today's proposal reflects input from
stakeholders including community groups, automobile manufacturers, environmental and public
health organizations, and state, local, and tribal governments through meetings with stakeholders
throughout the development of the proposal.
EPA plans to hold a virtual public hearing for this proposal. For information about how to
register for the hearing, please see our website or the hearing notice which will be published in
the Federal Register.
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