The
EPA Automotive
Trends Report
Greenhouse Gas Emissions,
Fuel Economy, and Technology
since 1975
United States
Jbpml Environmental Protection
^^^¦1 M m Agency
EPA-420-R-24-022 November 2024
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This technical report does not necessarily represent final EPA decisions, positions, or validation of
compliance data reported to EPA by manufacturers. It is intended to present technical analysis of issues
using data that are currently available and that may be subject to change. Historic data have been
adjusted, when appropriate, to reflect the result of compliance investigations by EPA or any other
corrections necessary to maintain data integrity.
The purpose of the release of such reports is to facilitate the exchange of technical information and to
inform the public of technical developments. This edition of the report supersedes all previous versions.
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THE ADMINISTRATOR
WASHINGTON, D.C. 20460
November 25, 2024
This year marks the 50th anniversary of the U.S. Environmental Protection Agency's Automotive Trends
Report. This report, which provides the public unparalleled insight into the automotive industry,
exemplifies not only the important work that the EPA is doing today, but also the long and rich history
of the agency's commitment to science, data and transparency.
The EPA was founded with strong bipartisan support to protect our environment and public health. The
EPA's partnership with the automotive industry was established from the very beginning, as the Clean
Air Act of 1970 tasked the fledgling agency with the ambitious goal of reducing car pollution. In the
years that followed, the EPA's emissions standards have catalyzed widespread use of new, clean
technologies; eliminated lead in gasoline; reduced evaporative emissions from vehicles; and ultimately
led to an impressive 99 percent reduction of common vehicle-tailpipe pollutants, such as hydrocarbons,
carbon monoxide, nitrogen oxides and particulate matter. These improvements have made direct
impacts on our air quality, improved people's health and saved lives.
Through all the incredible change and innovation that has taken place in the auto industry since 1975,
the Trends Report has been there to provide data, insight and transparency to the American public. The
EPA has been gathering and maintaining data that covers every new light-duty vehicle produced for sale
in the United States since model year 1975, and this unique dataset forms the foundation of this annual
resource. As with each iteration, this edition adds new analysis and more data, including new layers of
transparency through its online companion data tools. The report also provides a detailed look at how
automotive manufacturers are doing under the EPA's current light-duty greenhouse gas standards,
providing critical transparency on this important program. By understanding our history and by setting
a common baseline for where we are today, the Trends Report is part of the backbone of what the EPA
and the automotive industry have accomplished and will be able to accomplish in the future.
I am proud to introduce the 50th anniversary EPA Automotive Trends Report. This report continues to
be a critical way that the EPA delivers on its mission to protect human health and the environment for
more than half a century and counting. Congratulations to the incredible career team at the EPA who
have made this report possible. I hope that everyone who relies on this authoritative report finds it as
insightful and informative as ever.
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Table of Contents
1. Introduction 1
A. What's New This Year 1
B. Manufacturers in this Report 2
C. Fuel Economy and C02 Metrics in this Report 3
D. Other Sources of Data 5
2. Fleetwide Trends Overview 6
A. Overall Fuel Economy and C02 Trends 6
B. Production Trends 10
C. Manufacturer Fuel Economy and C02 Emissions 11
3. Vehicle Attributes 17
A. Vehicle Class and Type 17
B. Vehicle Weight 23
C. Vehicle Power 29
D. Vehicle Footprint 35
E. Vehicle Type and Attribute Tradeoffs 40
4. Vehicle Technology 47
A. Vehicle Propulsion 53
B. Vehicle Drivetrain 77
C. Technology Adoption and Comparison 83
5. Manufacturer GHG Compliance 92
A. Footprint-Based C02 Standards 94
B. Model Year Performance 98
C. GHG Program Credits and Deficits 127
D. GHG Program Credit Balances 141
Appendices: Methods and Additional Data
A. Sources of Input Data
B. Harmonic Averaging of Fuel Economy Values
C. Fuel Economy and C02 Metrics
D. Historical Changes in the Database and Methodology
E. Electric Vehicle and Plug-In Hybrid Metrics
F. Regulatory Car and Truck Definitions
G. Naming Conventions for Electrified Vehicles
H. Authors and Acknowledgments
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Table of Figures
igure 2.1. Estimated Real-World Fuel Economy and C02 Emissions 6
igure 2.2. Trends in Fuel Economy and C02 Emissions Since Model Year 1975 8
igure 2.3. Distribution of New Vehicle C02 Emissions by Model Year 9
igure 2.4. New Vehicle Production by Model Year 11
igure 2.5. Changes in Estimated Real-World Fuel Economy and C02 Emissions by Manufacturer 13
igure 3.1. Regulatory Classes and Vehicle Types Used in This Report 18
igure 3.2. Production Share and Estimated Real-World C02 Emissions 19
igure 3.3. Vehicle Type Distribution by Manufacturer for Model Year 2023 21
igure 3.4. Car-Truck Classification of SUVs with Inertia Weights of 4000 Pounds or Less 22
igure 3.5. Average New Vehicle Weight by Vehicle Type 24
igure 3.6. Inertia Weight Class Distribution by Model Year 25
igure 3.7. Average New Vehicle Weight by Vehicle Type and Powertrain 27
igure 3.8. Relationship of Inertia Weight and C02 Emissions 28
igure 3.9. Average New Vehicle Horsepower by Vehicle Type 30
igure 3.10. Horsepower Distribution by Model Year 31
igure 3.11. Average New Vehicle Horsepower by Vehicle Type and Powertrain 32
igure 3.12. Relationship of Horsepower and C02 Emissions 33
igure 3.13. Calculated 0-to-60 Time by Vehicle Type 35
igure 3.14. Footprint by Vehicle Type for Model Years 2008-2023 36
igure 3.15. Footprint Distribution by Model Year 37
igure 3.16. Average New Vehicle Footprint by Vehicle Type and Powertrain 38
igure 3.17. Relationship of Footprint and C02 Emissions 39
igure 3.18. Relative Change in Fuel Economy, Weight, Horsepower, and Footprint 41
igure 4.1. Vehicle Energy Flow for an Internal Combustion Engine Vehicle 47
igure 4.2. Manufacturer Use of Electrification Technologies for Model Year 2023 50
igure 4.3. Manufacturer Use of Emerging Technologies for Model Year 2023 52
igure 4.4. Gasoline Engine Production Share by Number of Cylinders 54
igure 4.5. Percent Change for Specific Gasoline Non-Hybrid Engine Metrics 56
igure 4.6. Production Share by Engine Technology 58
igure 4.7. Engine Metrics for Different Gasoline Technology Packages 60
igure 4.8. Gasoline Turbo Engine Production Share by Vehicle Type 62
igure 4-9. Gasoline Turbo Engine Production Share by Number of Cylinders 62
igure 4.10. Gasoline Non-Hybrid Stop/Start Production Share by Vehicle Type 64
igure 4.11. Gasoline Non-Hybrid Stop/Start Production Share by Number of Cylinders 64
igure 4.12. Gasoline Hybrid Engine Production Share by Vehicle Type 66
igure 4.13. Gasoline Hybrid Engine Production Share by Number of Cylinders 66
igure 4.14. Gasoline Hybrid Engine Production Share Hybrid Type 67
igure 4.15. Production Share of BEVs, PHEVs, and FCEVs 69
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Figure 4.16. Impact of BEVs and PHEVs 70
Figure 4.17. Battery Electric Vehicle Production Share by Vehicle Type 71
Figure 4.18. Plug-In Hybrid Vehicle Production Share by Vehicle Type 71
Figure 4.19. Charge Depleting Range and Fuel Economy for BEVs and PHEVs 72
Figure 4.20. BEV Energy Consumption by Weight and Vehicle Type 73
Figure 4.21. Diesel Engine Production Share by Vehicle Type 75
Figure 4.22. Diesel Engine Production Share by Number of Cylinders 75
Figure 4.23. Percent Change for Specific Diesel Engine Metrics 76
Figure 4.24. Transmission Production Share 79
Figure 4.25. Transmission By Engine Technology, Model Year 2023 80
Figure 4.26. Average Number of Transmission Gears 81
Figure 4.27. Front-, Rear-, and Four-Wheel Drive Production Share 82
Figure 4.28. Industry-Wide Car Technology Penetration after First Significant Use 84
Figure 4.29. Manufacturer Specific Technology Adoption over Time for Key Technologies 86
Figure 5.1. The GHG Compliance Process 92
Figure 5.2. 2012-2023 Model Year C02 Footprint Target Curves 95
Figure 5.3. Changes in 2-Cycle Tailpipe C02 Emissions by Manufacturer 100
Figure 5.4. Model Year 2023 Production of BEVs, PHEVs, and FCEVs 103
Figure 5.5. Model Year 2023 Advanced Technology Credits by Manufacturer 103
Figure 5.6. HFO-1234yf Adoption by Manufacturer 106
Figure 5.7. Fleetwide A/C Credits by Credit Type 108
Figure 5.8. Total A/C Credits by Manufacturer for Model Year 2023 108
Figure 5.9. Off-Cycle Menu Technology Adoption by Manufacturer, Model Year 2023 110
Figure 5.10. Total Off-Cycle Credits by Manufacturer for Model Year 2023 119
Figure 5.11. Performance and Standards by Manufacturer, Model Year 2023 128
Figure 5.12. Early Credits by Manufacturer 137
Figure 5.13. Total Credits Transactions 140
Figure 5.14. Manufacturer Credit Balance After Model Year 2023 143
Figure 5.15. Industry Performance and Standards, Credit Generation and Use 147
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Table of Tables
Table 1.1. Model Year 2023 Manufacturer Definitions 3
Table 1.2. Fuel Economy and C02 Metrics Used in this Report 4
Table 2.1. Production, Estimated Real-World C02, and Fuel Economy for Model Year 1975-2024 14
Table 2.2. Manufacturers and Vehicles with the Highest Fuel Economy, by Year 15
Table 2.3. Manufacturer Estimated Real-World Fuel Economy and C02 Emissions for Model Year
2022-2024 16
Table 3.1. Vehicle Attributes by Model Year 42
Table 3.2. Estimated Real-World Fuel Economy and C02 by Vehicle Type 43
Table 3.3. Model Year 2023 Vehicle Attributes by Manufacturer 44
Table 3.4. Model Year 2023 Estimated Real-World Fuel Economy and C02 by Manufacturer and
Vehicle Type 45
Table 3.5. Footprint by Manufacturer for Model Year 2022-2024 (ft2) 46
Table 4.1. Production Share by Drive Technology for Model Year 2023 51
Table 4.2. Production Share by Powertrain 87
Table 4.3. Production Share by Fuel Delivery Method 88
Table 4.4. Production Share by Gasoline Engine Technologies 89
Table 4.5. Production Share by Transmission Technologies 90
Table 4.6. Production Share by Drive Technology 91
Table 5.1. Manufacturer Footprint and Standards for Model Year 2023 97
Table 5.2. Production Multipliers by Model Year 102
Table 5.3. Model Year 2023 Off-Cycle Technology Credits from the Menu, by Manufacturer and
Technology (g/mi) 115
Table 5.4. Model Year 2023 Off-Cycle Technology Credits from an Alternative Methodology, by
Manufacturer and Technology (g/mi) 118
Table 5.5. Manufacturer Performance in Model Year 2023, All (g/mi) 121
Table 5.6. Industry Performance by Model Year, All (g/mi) 122
Table 5.7. Manufacturer Performance in Model Year 2023, Car (g/mi) 123
Table 5.8. Industry Performance by Model Year, Car (g/mi) 124
Table 5.9. Manufacturer Performance in Model Year 2023, Truck (g/mi) 125
Table 5.10. Industry Performance by Model Year, Truck (g/mi) 126
Table 5.11. Credits Earned by Manufacturers in Model Year 2023, All 130
Table 5.12. Total Credits Earned by Model Year, All 131
Table 5.13. Credits Earned by Manufacturers in Model Year 2023, Car 132
Table 5.14. Total Credits Earned by Model Year, Car 133
Table 5.15. Credits Earned by Manufacturers in Model Year 2023, Truck 134
Table 5.16. Total Credits Earned by Model Year, Truck 135
Table 5.17 Credit Expiration Schedule 138
Table 5.18. Example of a Deficit Offset with Credits from Previous Model Years 141
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Table 5.19. Final Credit Balance by Manufacturer for Model Year 2023 (Mg)
Table 5.20. Distribution of Credits by Expiration Date (Mg)
144
145
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1. Introduction
This annual report is part of the U.S. Environmental Protection Agency's (EPA) commitment
to provide the public with information about new light-duty vehicle greenhouse gas (GHG)
emissions, fuel economy, technology data, and auto manufacturers' performance in
meeting the agency's GHG emissions standards.
Since 1975, EPA has collected data on every new light-duty vehicle model sold in the United
States either from testing performed by EPA at the National Vehicle Fuel and Emissions
Laboratory in Ann Arbor, Michigan, or directly from manufacturers using official EPA test
procedures. These data are collected to support several important national programs,
including EPA criteria pollutant and GHG standards, the U.S. Department of
Transportation's National Highway Traffic Safety Administration (NHTSA) Corporate
Average Fuel Economy (CAFE) standards, and vehicle Fuel Economy and Environment
labels. This expansive data set allows EPA to provide a uniquely comprehensive analysis of
the automotive industry since 1975.
A. What's New This Year
This report is updated each year to reflect the most recent data available to EPA for all
model years, relevant regulatory changes, methodology changes, and any other changes
relevant to the auto industry. These changes can affect multiple model years; therefore,
this version of the report supersedes all previous reports. Significant developments
relevant for this edition of the report include the following:
This edition of the report is the 50th anniversary of the report and now contains data
spanning 50 years of automotive history. The report has continually evolved since its
inception, with this edition adding or updating many figures and analysis to better
explore recent industry electrification trends.
In March 2024, EPA finalized revised light-duty GHG standards for model year 2027-
2032, and in 2024 NHTSA subsequently published revised fuel economy standards for
model years 2027-2031. This report has been updated to reflect these changes
wherever relevant.
EPA has also updated the data available on the report webpage to provide more
details on the data used for this report. The report data webpage can be found here:
https://www.epa.gov/automotive-trends/explore-automotive-trends-data.
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B. Manufacturers in this Report
The underlying data for this report include every new light-duty vehicle offered for sale in
the United States. These data are presented by manufacturer throughout this report, using
model year 2023 manufacturer definitions determined by EPA and NHTSAfor
implementation of the GHG emission standards and CAFE program. For simplicity, figures
and tables in the executive summary and in Sections 1-4 show only the top 14
manufacturers, by production volume. These manufacturers produced at least 150,000
vehicles each in the 2023 model year and accounted for more than 97% of all production.
The compliance discussion in Section 5 includes all manufacturers, regardless of
production volume. Table 1.1 lists all manufacturers that produced vehicles in the U.S. for
model year 2023, including their associated makes, and their categorization for this report.
Only vehicle brands produced in model year 2023 are shown in this table; however, this
report contains data on many other manufacturers and brands that have produced
vehicles for sale in the U.S. since 1975.
When a manufacturer grouping changes under the GHG and CAFE programs, EPA applies
the new manufacturer definitions to all prior model years for the analysis of estimated real-
world C02 emission and fuel economy trends in Sections 1 through 4 of this report. This
maintains consistent manufacturer and make definitions over time, which enables better
identification of long-term trends. However, the compliance data that are discussed in
Section 5 of this report maintain the previous manufacturer definitions where necessary to
preserve the integrity of compliance data as accrued.
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Table 1.1. Model Year 2023 Manufacturer Definitions
Manufacturer
Makes in the U.S. Market
BMW
BMW, Mini, Rolls Royce
Ford
Ford, Lincoln, Roush, Shelby
General Motors (GM)
Buick, Cadillac, Chevrolet, GMC
Honda
Acura, Honda
(A
Hyundai
Genesis, Hyundai
Q)
Kia
Kia
Large
lufacti
Mazda
Mazda
Mercedes
Maybach, Mercedes
L.
CO
Nissan
Infiniti, Nissan
Stellantis
Alfa Romeo, Chrysler, Dodge, Fiat, Jeep, Maserati, Ram
Subaru
Subaru
Tesla
Tesla
Toyota
Lexus, Toyota
Volkswagen (VW)
Audi, Bentley, Bugatti, Lamborghini, Porsche, Volkswagen
Fisker
Fisker
V)
Q)
Jaguar Land Rover
Jaguar, Land Rover
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Lucid
Lucid
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Mitsubishi
Mitsubishi
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Rivian
Rivian
Volvo
Lotus, Polestar, Volvo
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Aston Martin*
Aston Martin
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Ferrari*
Ferrari
McLaren*
McLaren
* Small Volume Manufacturers
C. Fuel Economy and CO2 Metrics in this
Report
All data in this report for model years 1975 through 2023 are final and based on official
data submitted to EPA and NHTSA as part of the regulatory process. In some cases, this
report will show data for model year 2024, which are preliminary and are based on data,
including projected production volumes, provided to EPA by automakers prior to releasing
vehicles for sale to the public. All data in this report are based on production volumes
delivered for sale in the U.S. by model year. The model year production volumes may vary
from other publicized data based on calendar year sales. The report does not examine
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future model years, and past performance does not necessarily predict future industry
trends.
The carbon dioxide (CO2) emissions and fuel economy data in this report fall into one of
two categories based on the purpose of the data and the subsequent required emissions
test procedures. The first category is compliance data, which is measured using laboratory
tests required by law for CAFE and adopted by EPA for GHG compliance. Compliance data
are measured using EPA city and highway test procedures (the "2-cycle" tests), and
fleetwide averages are calculated by weighting the city and highway test results by 55% and
45%, respectively. These procedures are required for compliance; however, they no longer
accurately reflect real-world driving. Compliance data may also encompass optional
performance credits and adjustments that manufacturers can use towards meeting their
emissions standards.
The second category is estimated real-world data, which is measured using additional
laboratory tests to capture a wider range of operating conditions (including hot and cold
weather, higher speeds, and faster accelerations) encountered by an average driver. This
expanded set of tests is referred to as "5-cycle" testing. City and highway results are
weighted 43% city and 57% highway, consistent with fleetwide driver activity data. The city
and highway values are the same values found on new vehicle fuel economy labels;
however, the label combined value is weighted 55% city and 45% highway. Unlike
compliance data, the method for calculating real-world data has evolved over time, along
with technology and driving habits.
Table 1.2. Fuel Economy and CO2 Metrics Used in this Report
Current
C02 and Fuel Economy
City/ Highway
Current Test
Data Category
Purpose
Weighting
Basis
Compliance
Basis for manufacturer
compliance with standards
55% / 45%
2-cycle
Estimated Real-World
Best estimate of real-world
performance
43% / 57%
5-cycle
This report will show estimated real-world data except for the discussion specific to the
GHG regulations in Section 5 and Executive Summary Figures ES-6 through ES-8. The
compliance CO2 data generally should not be compared to the real-world CO2 data
presented elsewhere in this report. For a more detailed discussion of the fuel economy and
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C02 data used in this report, including the differences between real-world and compliance
data, see Appendices C and D.
D. Other Sources of Data
EPA continues to update detailed data from this report, including all years of the light-duty
GHG standards, to the EPA Automotive Trends website. We encourage readers to visit
https://www.epa.gov/automotive-trends and explore the data. EPA will continue to add
content and tools on the web to allow transparent access to public data.
Additional detailed vehicle data is available on www.fueleconomy.gov. which is a web
resource that helps consumers make informed fuel economy choices when purchasing a
vehicle and achieve the best fuel economy possible from the vehicle they own. EPA
supplies the underlying data, much of which can be downloaded at
https://fueleconomy.gov/feg/download.shtml.
In addition, EPA's Green Vehicle Guide is an accessible, transportation-focused website that
provides information, data, and tools on greener options for moving goods and people.
This report does not provide data about NHTSA's CAFE program. For more information
about CAFE and manufacturer compliance with the CAFE fuel economy standards, see the
CAFE Public Information Center, which can be accessed at
https://one.nhtsa.gov/cafe pic/home.
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2. Fleetwide Trends Overview
The automotive industry continues to make progress towards lower tailpipe CO2 emissions
and higher fuel economy in recent years. This section provides an update on the estimated
real-world tailpipe CO2 emissions and fuel economy for the overall fleet, and for
manufacturers based on final model year 2023 data. The unique, historical data on which
this report is based also provide an important backdrop for evaluating the more recent
performance of the industry. Using that data, this section will also explore basic fleetwide
trends in the automotive industry since EPA began collecting data in model year 1975.
A. Overall Fuel Economy and CO2 Trends
The downward trend for the average
new vehicle real-world CO2 emission
rate continued in model year 2023. The
average model year 2023 vehicle
produced 319 grams per mile (g/mi) of s
CO2, which is 18 g/mi less than the |
w
previous model year, and the lowest &
emission rate on record. Real-world 8
fuel economy increased by 1.1 mpg to |
a record high 27.1 mpg.1 The trends in J
CO2 emissions and fuel economy since
1975 are shown in Figure 2.1.
Many factors are responsible for g
decreasing new vehicle C02 emissions, >;
including increased production of a §
O
wide range of technologies. This ^
D
includes increased production of |
O
battery electric vehicles (BEVs) and §
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plug-in hybrids (PHEVs) which have £
noticeably influenced the overall trends.
Without BEVs and PHEVs, the average new
Figure 2.1. Estimated Real-World
Fuel Economy and CO2 Emissions
i 1 1 1 1 1
1975 1985 1995 2005 2015 2025
Model Year
1 EPA generally uses unrounded values to calculate values in the text, figures, and tables in this report. This
approach results in the most accurate data but may lead to small apparent discrepancies due to rounding.
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vehicle real-world CO2 emission rate was 37 g/mi higher, and the year over year
improvement in model year 2023 was only 1.4 g/mi.
Preliminary data suggest that the average new vehicle CO2 emission rate and fuel economy
will continue to improve in model year 2024, and that the impact of BEVs and PHEVs will
continue to grow. The preliminary model year 2024 data are based on production
estimates provided to EPA by manufacturers months before the vehicles go on sale. The
data are a useful indicator, however there is always uncertainty associated with such
projections, and we caution the reader against focusing only on these data. Projected data
are shown in Figure 2.1 as a dot because the values are based on manufacturer projections
rather than final data.
While the most recent annual changes often receive the most public attention, the greatest
value of the Trends database is to document long-term trends. The magnitude of changes
in annual CO2 emissions and fuel economy tend to be small relative to longer, multi-year
trends. Figure 2.2 shows fleetwide estimated real-world C02 emissions and fuel economy
for model years 1975-2023. Over this timeframe there have been three basic phases: 1) a
rapid improvement of CO2 emissions and fuel economy between 1975 and 1987, 2) a
period of slowly increasing CO2 emissions and decreasing fuel economy through 2004, and
3) decreasing C02 emissions and increasing fuel economy through the current model year.
Vehicle CO2 emissions and fuel economy are inversely related for gasoline and diesel
vehicles, but not for electric vehicles. Since gasoline and diesel vehicles have made up the
vast majority of vehicle production since 1975, Figure 2.2 shows an inverted, but highly
correlated relationship between CO2 emissions and fuel economy. BEVs, which account for
a small but growing portion of vehicle production, have zero tailpipe CO2 emissions,
regardless of fuel economy (as measured in miles per gallon equivalent, or mpge). The fuel
economy of BEVs, in mpge, is included in the fleet average shown in Figure 2.2 and
elsewhere in this report. If electric vehicles continue to capture a larger market share, the
overall relationship between fuel economy and tailpipe CO2 emissions will change.
4%.
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Figure 2.2. Trends in Fuel Economy and CO2 Emissions Since Model Year 1975
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300-
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20-
16-
12-
1988 to 2004
-12%
2005 to 2023
-31%
2005 to 2023
+40%
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
Model Year
Another way to look at CO2 emissions over time is to examine how the distribution of new
vehicle emission rates have changed. Figure 2.3 shows the distribution of real-world
tailpipe C02 emissions for all vehicles produced within each model year. Half of the vehicles
produced each year are clustered within a small band around the median CO2 emission
rate, as shown in blue. The remaining vehicles show a much wider spread, especially in
recent years as the production of electric vehicles with zero tailpipe emissions has
increased. The lowest CC>2-emitting vehicles have all been hybrids or battery electric
vehicles since the first hybrid was introduced in model year 2000, while the highest C02-
emitting vehicles are generally performance vehicles or large trucks. The introduction of
zero tailpipe emission BEVs in model year 2011 and their growth past 5% market share in
model year 2022 are both visible in Figure 2.3.
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Figure 2.3. Distribution of New Vehicle C02 Emissions by Model Year2
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
It is important to note that the methodology used in this report for calculating estimated
real-world fuel economy and CO2 emission values has changed over time to reflect
changing vehicle technology and operation. For example, the estimated real-world fuel
economy for a 1980s vehicle is somewhat higher than it would be if the same vehicle were
being produced today. These changes are small for most vehicles, but larger for very high
fuel economy vehicles. See Appendices C and D for a detailed explanation of fuel economy
metrics and their changes over time.
2 Electric vehicles prior to 2011 are not included in this figure due to limited data. However, those vehicles were
available in small numbers only.
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B. Production Trends
This report is based on the total number of vehicles produced by manufacturers for sale in
the United States by model year. Model year is the manufacturer's annual production
period, which includes January 1 of the same calendar year. A typical model year for a
vehicle begins in fall of the preceding calendar year and runs until late in the next calendar
year. However, model years vary among manufacturers and can occur between January 2
of the preceding calendaryear and the end of the calendaryear. Model year production
data is the most direct way to analyze emissions, fuel economy, technology, and
compliance trends because vehicle designs within a model year do not typically change.
The use of model year production may lead to some short-term discrepancies with other
sources, which typically report calendar year sales; however, sales based on the calendar
year generally encompass more than one model year, which complicates any analysis.
Since the inception of this report, production of vehicles for sale in the United States has
grown on average roughly 0.4% year over year, but there have been significant swings up
or down in any given model year due to the impact of multiple market forces. For example,
in model year 2009, economic conditions resulted in the lowest model year production
since the start of this report, at 9.3 million vehicles. Production rebounded over the next
several model years, reaching an all-time high of more than 17 million vehicles in model
year 2017. Model year 2020 production fell 15% from the previous year, as the COVID-19
pandemic had wide-ranging impacts on the economy as well as vehicle production and
supply chains. Figure 2.4 shows the production trends by model year for model years 1975
to 2023. Model year 2023 production was 14,196,404 vehicles.
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Figure 2.4. New Vehicle Production by Model Year
20,000
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15,000
10,000
5,000
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
C. Manufacturer Fuel Economy and CO2
Emissions
Along with the overall industry, most manufacturers have improved new vehicle CO2
emission rates and fuel economy in recent years. Manufacturer trends over the last five
years are shown in Figure 2.5. This span covers the approximate length of a vehicle
redesign cycle, and it is likely that most vehicles have undergone design changes in this
period, resulting in a more accurate depiction of recent manufacturer trends than focusing
on a single year. Changes over this time period can be attributed to both vehicle design
and changing vehicle production trends. The change in production trends, and the impact
on the trends shown in Figure 2.5 are discussed in more detail in the next section.
Over the last five years, as shown in Figure 2.5, nine of the fourteen largest manufacturers
selling vehicles in the U.S. decreased new vehicle estimated real-world CO2 emission rates.
Tesla was unchanged because their all-electric fleet produces no tailpipe CO2 emissions.
Between model years 2018 and 2023, Mercedes achieved the largest reduction in CO2
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emissions at 73 g/mi. Volkswagen (VW) achieved the second largest reduction in overall CO2
tailpipe emissions, at 44 g/mi, and BMW had the third largest reduction in overall CO2
tailpipe emissions at 34 g/mi. Ford, Hyundai, Kia, Nissan, Stellantis, and Toyota also
achieved overall emission reductions.
Four manufacturers increased new vehicle C02 emission rates between model years 2018
and 2023 (Honda, Mazda, GM, and Subaru). Honda had the largest increase at 18 g/mi.
Mazda had the second largest increase at 12 g/mi, and General Motors (GM) had the third
largest increase at 11 g/mi.
For model year 2023 alone, Tesla's all-electric fleet had the lowest tailpipe CO2 emissions of
all large manufacturers at 0 g/mi. Tesla was followed by Kia at 289 g/mi, Hyundai at 292
g/mi, and Mecedes at 304 g/mi. At 402 g/mi, Stellantis had the highest new vehicle average
CO2 emissions and lowest fuel economy of the large manufacturers in model year 2023,
followed by GM at 396 g/mi and Ford at 374g/mi. Tesla also had the highest overall fuel
economy, followed by Kia, Hyundai, and Nissan.
Figure 2.5 is organized according to increasing fuel economy values, but the order would
change if based on CO2 emission rates. This is due the fact that BEVs and PHEVs have a
different relationship between tailpipe emissions and fuel economy than other vehicles,
and different rates of adoption of BEVs and PHEVs between manufacturers.
For vehicles powered only with gasoline, fuel economy and tailpipe CO2 emissions are
related via a straightforward inverse relationship where increasing fuel economy decreases
C02 emissions. However, the relationship between fuel economy and tailpipe C02
emissions is different for PHEVs, which use electricity in addition to gasoline, and EVs,
which use only electricity. For PHEVs and BEVs, the electricity used by the vehicle results in
0 g/mi of tailpipe CO2 emissions. However, the overall efficiency of PHEVs and BEVs is
reported in terms of mpge, or miles-per-gallon-of-gasoline-equivalent, which is a measure
of the total energy the vehicle uses, in terms of the amount of energy in a gallon of
gasoline. Therefore, the relationship between mpge and tailpipe CO2 emission is not the
same for PHEVs and BEVs as it is for gasoline vehicles.
As a result, manufacturers who produce more BEVs and PHEVs will have lower C02
emissions relative to their fuel economy than other manufacturers that produce fewer
BEVs and PHEVs. For example, in model year 2023 BMW and Mazda had the same average
fuel economy of 27.6 mpge, but BMW, which produced both BEVS and PHEVs, has a lower
average CO2 rate than Mazda, which did not produce BEVs or PHEVs.
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Figure 2.5. Changes in Estimated Real-World Fuel Economy and CO2 Emissions by Manufacturer
Fuel Economy (MPG), 2018 - 2023 C02 Emissions (g/mi), 2018 - 2023
Tesla
Kia
Hyundai
Nissan
Subaru
Honda
BMW
Mazda
Toyota
Mercedes
VW
Ford
GM
Stellantis
All Manufacturers
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Table 2.1. Production, Estimated Real-World C02, and Fuel Economy for Model Year 1975-2024
Model Year
Production
(000)
Real-World
C02 (g/mi)
Real-World
FE(MPG)
Model Year
Production
(000)
Real-World
C02 (g/mi)
Real-World
FE(MPG)
1975
10,224
681
13.1
2000
16,571
450
19.8
1976
12,334
625
14.2
2001
15,605
453
19.6
1977
14,123
590
15.1
2002
16,115
457
19.5
1978
14,448
562
15.8
2003
15,773
454
19.6
1979
13,882
560
15.9
2004
15,709
461
19.3
1980
11,306
466
19.2
2005
15,892
447
19.9
1981
10,554
436
20.5
2006
15,104
442
20.1
1982
9,732
425
21.1
2007
15,276
431
20.6
1983
10,302
426
21.0
2008
13,898
424
21.0
1984
14,020
424
21.0
2009
9,316
397
22.4
1985
14,460
417
21.3
2010
11,116
394
22.6
1986
15,365
407
21.8
2011
12,018
399
22.3
1987
14,865
405
22.0
2012
13,449
377
23.6
1988
15,295
407
21.9
2013
15,198
368
24.2
1989
14,453
415
21.4
2014
15,512
369
24.1
1990
12,615
420
21.2
2015
16,739
360
24.6
1991
12,573
418
21.3
2016
16,278
359
24.7
1992
12,172
427
20.8
2017
17,016
357
24.9
1993
13,211
426
20.9
2018
16,260
353
25.1
1994
14,125
436
20.4
2019
16,139
356
24.9
1995
15,145
434
20.5
2020
13,721
349
25.4
1996
13,144
435
20.4
2021
13,812
347
25.4
1997
14,458
441
20.2
2022
12,860
337
26.0
1998
14,456
442
20.1
2023
14,196
319
27.1
1999
15,215
451
19.7
2024 (prelim)
305
28.0
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
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Table 2.2. Manufacturers and Vehicles with the Highest Fuel Economy, by Year
Overall Vehicle with Gasoline (Non-Hybrid) Vehicle
Manufacturer
Manufacturer
Highest Fuel Economy4
with Highest Fuel Economy
with Highest
with Lowest
Real-
Real-
Fuel Economy3
Fuel Economy
World FE
Engine
World FE
Model Year
(mpg)
(mpg)
Vehicle
(mpg)
Type
Gasoline Vehicle
(mpg)
1975
Honda
Ford
Honda Civic
28.3
Gas
Honda Civic
28.3
1980
VW
Ford
VW Rabbit
40.3
Diesel
Nissan 210
36.1
1985
Honda
Mercedes
GM Sprint
49.6
Gas
GM Sprint
49.6
1990
Hyundai
Mercedes
GM Metro
53.4
Gas
GM Metro
53.4
1995
Honda
Stellantis
Honda Civic
47.3
Gas
Honda Civic
47.3
2000
Hyundai
Stellantis
Honda Insight
57.4
Hybrid
GM Metro
39.4
2005
Honda
Ford
Honda Insight
53.3
Hybrid
Honda Civic
35.1
2010
Hyundai
Mercedes
Honda FCX
60.2
FCEV
Smart Fortwo
36.8
2015
Mazda
Stellantis
BMW i3
121.3
BEV
Mitsubishi Mirage
39.5
2016
Mazda
Stellantis
BMW i3
121.3
BEV
Mazda 2
37.1
2017
Honda
Stellantis
Hyundai loniq
132.6
BEV
M
tsubishi M
rage
41.5
2018
Tesla
Stellantis
Hyundai loniq
132.6
BEV
M
tsubishi M
rage
41.5
2019
Tesla
Stellantis
Hyundai loniq
132.6
BEV
M
tsubishi M
rage
41.6
2020
Tesla
Stellantis
Tesla Model 3
138.6
BEV
M
tsubishi M
rage
41.6
2021
Tesla
Stellantis
Tesla Model 3
139.1
BEV
M
tsubishi M
rage
41.6
2022
Tesla
Stellantis
Lucid Air G
131.4
BEV
M
tsubishi M
rage
41.6
2023
Tesla
Stellantis
Lucid Air AWD
140.3
BEV
M
tsubishi M
rage
41.6
2024 (prelim)
Tesla
Stellantis
Hyundai loniq 6
137.0
BEV
Mitsubishi Mirage
40.0
3 Manufacturers below the 150,000 threshold for "large" manufacturers are excluded in years they did not meet the threshold.
4 Vehicles are shown based on estimated real-world fuel economy as calculated for this report. These values will differ from values found on the fuel
economy labels at the time of sale. For more information on fuel economy metrics see Appendix C.
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Table 2.3. Manufacturer Estimated Real-World Fuel Economy and CO2 Emissions for Model Year 2022-2024
MY 2022 Final
MY 2023 Final
MY2024 Preliminary
FE Change
C02 Change
Real-World
Real-World
Real-World
from
Real-World
from
Real-World
Real-World
FE
C02
FE
MY 2022
C02
MY 2022
FE
C02
Manufacturer
(mpg)
(g/mi)
(mpg)
(mpg)
(g/mi)
(g/mi)
(mpg)
(g/mi)
BMW
25.3
344
27.6
2.3
305
-39
29.1
285
Ford
23.1
380
23.2
0.1
374
-6
23.8
365
GM
22.0
406
22.4
0.4
396
-9
23.9
366
Honda
28.7
309
28.3
-0.4
314
4.4
29.8
296
Hyundai
29.1
302
29.8
0.7
292
-11
30.0
286
Kia
28.6
306
30.4
1.7
289
-17
29.6
289
Mazda
27.0
328
27.6
0.5
322
-6
27.8
319
Mercedes
23.7
372
27.5
3.7
304
-68
30.2
268
Nissan
27.4
322
28.9
1.4
305
-17
28.6
306
Stellantis
21.3
415
21.8
0.5
402
-13
23.3
360
Subaru
27.9
318
28.4
0.4
311
-7
28.0
316
Tesla
119.3
0
120.6
1.3
0
0
117.4
0
Toyota
27.8
319
27.5
-0.3
322
2
28.3
310
VW
26.1
333
27.0
1.0
317
-16
27.9
305
All Manufacturers
26.0
337
27.1
1.1
319
-18
28.0
305
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
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3. Vehicle Attributes
Vehicle CO2 emissions and fuel economy are strongly influenced by vehicle design
parameters, including weight, power, acceleration, and size. In general, vehicles that are
larger, heavier, and more powerful typically have lower fuel economy and higher CO2
emissions than other comparable vehicles. This section focuses on several key vehicle
design attributes that impact CO2 emissions and fuel economy and evaluates the impact of
a changing automotive marketplace on overall fuel economy.
A. Vehicle Class and Type
Manufacturers offer a wide variety of light-duty vehicles in the United States. Under the
CAFE and GHG regulations, new vehicles are separated into two distinct regulatory classes,
passenger cars and light trucks, and each vehicle class has separate GHG and fuel economy
standards5. Vehicles can qualify as light trucks based on the vehicle's functionality as
defined in the regulations (for example if the vehicle can transport cargo on an open bed or
the cargo carrying volume is more than the passenger carrying volume). Vehicles that have
a gross vehicle weight rating6 (GVWR) of more than 6,000 pounds or have four-wheel drive
and meet various off-road requirements, such as ground clearance, can also qualify as light
trucks. Vehicles that do not meet these requirements are considered cars. For more
information on car and truck regulatory definitions, see Appendix F.
Pickup trucks, vans, and minivans are classified as light trucks under NHTSA's regulatory
definitions, while sedans, coupes, and wagons are generally classified as cars. Sport utility
vehicles (SUVs) can fall into either category depending on the relevant attributes of the
specific vehicle. Based on the CAFE and GHG regulatory definitions, most two-wheel drive
SUVs under 6,000 pounds GVW are classified as cars, while most SUVs that have four-wheel
drive or are above 6,000 pounds GVW are considered trucks. SUV models that are less than
6,000 pounds GVW can have both car and truck variants, with two-wheel drive versions
classified as cars and four-wheel drive versions classified as trucks. As the fleet has
changed over time, the line drawn between car and truck classes has also evolved. This
5 Passenger vehicles (cars) and light trucks (trucks) are defined by regulation in EPA's 40 CFR 86.1818-12 which
references the Department of Transportation's 49 CFR 523.4-523.5.
6 Gross vehicle weight rating is the combined weight of the vehicle, passengers, and cargo of a fully loaded
vehicle.
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report uses the current regulatory car and truck definitions, and these changes have been
propagated back throughout the historical data.
This report further separates the car and truck regulatory classes into five vehicle type
categories based on their body style classifications under the fuel economy labeling
program^The regulatory car class is divided into two vehicle types: sedan/wagon and car
SUV. The sedan/wagon vehicle type includes mini-compact, subcompact, compact, midsize,
large, and two-seater cars, hatchbacks, and station wagons. Vehicles that are SUVs under
the labeling program and cars under the CAFE and GHG regulations are classified as car
SUVs in this report. The truck class is divided into three vehicle types: pickup, minivan/van,
and truck SUV. Vehicles that are SUVs under the labeling program and trucks under the
CAFE and GHG regulations are classified as truck SUVs. Figure 3.1 shows the two regulatory
classes and five vehicle types used in this report. The distinction between these five vehicle
types is important because different vehicle types have different design objectives, and
different challenges and opportunities for improving fuel economy and reducing CO2
emissions.
Figure 3.1. Regulatory Classes and Vehicle Types Used in This Report
Regulatory Class Vehicle Type
Fuel Economy and CO2 by Vehicle Type
The production volume of the different vehicle types has changed significantly over time.
Figure 3.2 shows the production shares of each of the five vehicle types since model year
1975. The overall new vehicle market continues to move away from the sedan/wagon
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vehicle type towards a combination of truck SUVs, car SUVs, and pickups. Sedan/wagons
were the dominant vehicle type in 1975, when more than 80% of vehicles produced were
sedan/wagons. Since then, their production share has generally been falling, and with a
market share of only 25% in model year 2023, sedans/wagons now hold less than a third of
the market share they held in model year 1975. Vehicles that could be classified as a car
SUV or truck SUV were a very small part of the production share in 1975 but now account
for more than half of all new vehicles produced. In model year 2023, both car and truck
SUVs increased market share, to their highest combined percentage of market share. Truck
SUV production share reached 45%, while Car SUV production share reached 12%. The
production share of pickups has fluctuated over time, peaking at 19% in 1994 and then
falling to 10% in 2012. Pickups have generally increased in recent years and accounted for
15% of the market in model year 2023. Minivan/vans captured less than 5% of the market
in 1975, increased to 11 % in model year 1995 but have fallen since to less than 3% of
vehicle production in recent years. The projected 2024 data shows a vehicle type
distribution that is similar to model year 2023.
Figure 3.2. Production Share and Estimated Real-World CO2 Emissions
The truck regulatory class (including pickups, minivan/vans, and truck SUVs) fell slightly in
the model year 2023, for the first time in twelve years. However, the overall truck
production share remained near an all-time high of 62%. Trucks are projected to increase
-------
overall production share slightly in 2024. In Figure 3.2, the dashed line between the car
SUVs and truck SUVs shows the split in car and truck regulatory class.
Figure 3.2, also shows estimated CO2 emissions for each vehicle type since 1975. In model
year 2023, compared to model year 2022, the four largest vehicle types continued their
trends of reduced CO2 emissions and increased fuel economy. Minivan/vans, which
accounted for less than 3% of new vehicle production in model year 2023, had C02
emissions that were unchanged. Most notable is the 60 g/mi, or 24%, reduction, in the
average new vehicle real-world CO2 emissions within car SUVs. This improvement in CO2
emissions stems from the influx of BEVs within car SUVs, with BEVs now accounting for
36% of all MY 2023 car SUVs. The car SUV vehicle type now has the lowest average new
vehicle C02 emissions. In the preliminary model year 2024 data (shown as a dot on Figure
3.2), all vehicle types except Car SUV are expected to improve CO2 emissions from model
year 2023, while car SUV CO2 emissions are projected to remain the same.
In terms of fuel economy, car SUVs increased fuel economy by 7.2 mpg, to become the
vehicle type with the highest fuel economy. Sedan/wagons increased fuel economy by 0.9
mpg, pickups increased by 0.5 mpg, and truck SUVs increased by 0.4 mpg, while
minivans/vans decreased by 0.1 mpg. Four of the five vehicle types, pickups being the
exception, now achieve fuel economy more than double what they achieved in 1975. Four
of the five vehicle types are also expected to improve fuel economy further based on
preliminary model year 2024 data, with only car SUVs declining slightly.
Overall fuel economy and C02 emissions trends depend on the trends within the five
vehicle types, but also on the market share of each of the vehicle types. Since 1975, the
market has shifted dramatically away from sedan/wagons and towards truck SUVs and car
SUVs. Until recently, the sedan/wagon vehicle type was the most efficient, so the market
shifts toward other vehicle types with lower fuel economy and higher CO2 emissions offset
some of the fleetwide benefits that otherwise would have been achieved from the
improvements within each vehicle type. However, the growth of electric vehicles,
particularly within the car SUV vehicle type, is changing the relationship between vehicle
types and overall average new vehicle real-world CO2 emissions.
The model year 2023 production breakdown by vehicle type for each manufacturer is
shown in Figure 3.3. There are clear variations in production distribution by manufacturer.
BMW had the highest production of sedan/wagons at 47%, Tesla had the highest
percentage of car SUVs at 55%, Mazda had the highest percentage of truck SUVs at 89%,
Ford had the highest percentage of pickups at 44%, and Stellantis had the highest
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percentage of minivan/vans at 10%. The distribution of production between vehicle types
remained similar between model year 2022 and 2023. Nissan, Tesla, and VW each
decreased sedan/wagon production by more than 10 percentage points, moving
production towards a combination of car and truck SUVs. GM increased their pickup
production share by 12 percentage points, while decreasing the percentage of truck SUVs.
All other vehicle type production shifts within each manufacturer were less than 10
percentage points.
Figure 3.3. Vehicle Type Distribution by Manufacturer for Model Year 2023
100%
£
CO
_c
(J)
c
o
75%-
2 50%
o
T3
O
25% _
0%_
Lower average CO Emissions
Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Mini van/Van
I Pickup
For some manufacturers, changes in the mix of vehicle types they produce has also led to a
significant impact on their overall new vehicle CO2 emissions and fuel economy. As shown
in Figure 2.5, Honda had the largest increase in average CO2 emission over the last five
years, at 18 g/mi. The increase in emissions for Honda was due to a shift in production
towards truck SUVs and pickups along with increases in the emission rates within both of
those vehicle types compared to model year 2018. Mazda had the second largest increase
at 12 g/mi, due entirely to a shift from 36% to 89% truck SUV production.
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A Closer Look at SUVs
SUV Classification
Since 1975, the production share of SUVs in the United States has increased in all but 10
years, and now accounts for 58% of all vehicles produced (see Figure 3.2). This includes both
the car and truck SUV vehicle types.
Based on the regulatory definitions of cars and trucks, SUVs that are less than 6,000 pounds
GVWR can be classified as either cars or trucks, depending on design requirements such as
minimum angles and clearances, and whether the vehicle has 2-wheel drive or 4-wheel drive.
This definition can lead to similar vehicles having different car or truck classifications, and
different requirements under the GHG and CAFE regulations. One trend of particular interest
is the classification of SUVs as either car SUVs or truck SUVs.
This report does not track GVWR, but instead tracks weight using inertia weight classes,
where inertia weight is the weight of the empty vehicle, plus 300 pounds (see weight
discussion on the next page). Figure 3.4 shows the breakdown of SUVs into the car and truck
categories over time for vehicles with an inertia weight of 4,000 pounds or less. Heavier
vehicles were excluded, as these vehicles generally exceed 6,000 pounds GVWR and are
classified as trucks. The relative percentage of SUVs with an inertia weight of 4,000 pounds or
less that meet the current regulatory truck definition increased to 72% in model year 2023,
which is the highest percentage of production since at least model year 2000. Model year
2024 data is projected to have a slightly lower ratio of truck SUVs.
Figure 3.4. Car-Truck Classification of SUVs with Inertia Weights of 4000
Pounds or Less
i ( 1 1 1 H
2000 2005 2010 2015 2020 2025
Model Year
a
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B. Vehicle Weight
Vehicle weight is a fundamental vehicle attribute and an important metric for analysis
because vehicles with a higher weight, other things being equal, will require more energy to
move. For vehicles with an internal combustion engine, this higher energy requirement
generally results in more C02 emissions and decreased fuel economy. Among battery
electric vehicles (BEVs), increased weight will likely decrease the overall efficiency of the
vehicle, measured either in kilowatt-hours per 100 miles or miles per gallon of gasoline
equivalent (mpge). However, it will not increase tailpipe CO2 emissions, since BEVs do not
have tailpipe emissions regardless of the weight of the vehicle. Due to the weight of battery
packs, electric vehicles are likely to weigh more than comparable internal combustion
engine vehicles.
All vehicle weight data in this report are based on inertia weight classes. Each inertia weight
class represents a range of loaded vehicle weights, or vehicle curb weights7 plus 300
pounds. Vehicle inertia weight classes are in 250-pound increments for classes below 3,000
pounds, while inertia weight classes over 3,000 pounds are divided into 500-pound
increments.
Vehicle Weight by Vehicle Type
Figure 3.5 shows the average new vehicle weight for all vehicle types since model year
1975. From model year 1975 to 1981, average vehicle weight dropped 21 %, from 4,060
pounds per vehicle to about 3,200 pounds; this was likely driven by both increasing fuel
economy standards (which, at the time, were universal standards, and not based on any
type of vehicle attribute) and higher gasoline prices.
From model year 1981 to model year 2004, the trend reversed, and average new vehicle
weight began to slowly but steadily climb. By model year 2004, average new vehicle weight
had increased 28% from model year 1981 and reached 4,111 pounds per vehicle, in part
because of the increasing truck share. Average vehicle weight in model year 2023 was
about 6% above 2004 and is currently at the highest point on record, at 4,371 pounds.
Preliminary model year 2024 data suggest that weight will continue to increase.
In model year 1975, the difference between the heaviest and lightest vehicle types was
about 215 pounds, or about 5% of the average new vehicle. In contrast, for model year
7 Vehicle curb weight is the weight of an empty, unloaded vehicle.
ID
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2023, the difference between the heaviest and lightest vehicle types was about 1,535
pounds, or about 35% of the average new vehicle weight. In 1975, the average new
sedan/wagon outweighed the average new pickup by about 45 pounds, but the different
weight trends over time for each of these vehicle types led to a very different result in
model year 2023, with the average new pickup outweighing the average new sedan/wagon
by about 1,535 pounds. Pickups are below their model year 2014 high of 5,485 pounds per
vehicle, due in part to vehicle redesigns of popular truck models and the use of weight
saving designs, such as aluminum bodies. However other trends, such as the growth in
battery electric vehicles (BEVs), appears to be pushing vehicle weights back up.
Figure 3.5. Average New Vehicle Weight by Vehicle Type
ALL Sedan/Wagon Car SUV
1975 1985 1995 2005 2015 20251975 1985 1995 2005 2015 20251975 1985 1995 2005 2015 2025
Model Year
Figure 3.6 shows the annual production share of different inertia weight classes for new
vehicles since model year 1975. In model year 1975, there were significant sales in all
weight classes from <2,750 pounds to 5,500 pounds. In the early 1980s, the largest vehicles
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disappeared from the market, and light cars <2,750 pounds inertia weight briefly captured
more than 25% of the market. Since then, cars in the <2,750-pound inertia weight class
have all but disappeared, and the market has moved towards heavier vehicles.
Interestingly, the heaviest vehicles in model year 1975 were mostly large cars, whereas the
heaviest vehicles today are largely pickups and truck SUVs.
Figure 3.6. Inertia Weight Class Distribution by Model Year
Weight
¦
<2750
2750
3000
3500
4000
4500
¦
5000
¦
5500
¦
6000
>6000
100%
75% H
CD
i
cc
.c
CO
.2 50%
o
"O
o
25%
i 1 1 1 1 1 1 1 1 1 1
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Vehicle Weight and Technology
In addition to the changes in vehicle type, the changing powertrain technologies used in
recent model years have also impacted typical vehicle weight. For example, BEVs require a
battery that can store enough energy to propel the vehicle over the design range of the
vehicle, which for many current BEVs is more than 300 miles. The large battery required to
hold that amount of energy increases the weight of the vehicle, often making it heavier
than an equivalent internal combustion engine vehicle.
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Figure 3.7 shows the average weight, by vehicle type, of internal combustion engine (ICE)
vehicles (including those with stop/start, but not hybrids or PHEVs) compared to BEVs and
PHEVs. The average of all vehicles within each vehicle type (including hybrids, PHEVs, and
FCEVs) is also shown as a solid black bar. For each vehicle type, BEVs and PHEVs are heavier
than their ICE counterparts. BEVs and PHEVs appear to be increasing the overall weight
within each vehicle type, with the magnitude of the impact dependent on the uptake of
BEVs and PHEVs within each vehicle type.
Overall vehicle weight has generally been trending upwards for several decades, as shown
in Figure 3.5. This trend has driven by many factors, including market shifts between
vehicle types. The weight difference between ICE vehicles and BEV/PHEV vehicles shown for
most vehicle types in Figure 3.7 is comparable to the difference in weight between ICE
sedan/wagons and ICE truck SUVs. Overall vehicle production has by and large been
moving away from sedan/wagons towards truck SUVs, as shown in Figure 3.2, for decades.
This market shift over time has, to date, had much more of an impact on overall new
vehicle average weight than the recent emergence of BEVs and PHEVs.
It is also important to note that even within vehicle types shown in Figure 3.7, the BEVs and
PHEVs available may not be exactly comparable to the ICE vehicles. For example, the only
electric vehicle pickup trucks are large full-sized pickups, while the ICE category includes
some smaller pickup trucks. This difference is likely increasing the weight difference shown
for pickups in Figure 3.7.
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Figure 3.7. Average New Vehicle Weight by Vehicle Type and Powertrain
7000-
6000-
tn
_Q
O)
CC
0
5000
4000
3000
¦5= 2000
1000
0
1 1
Sedan/Wagon Car
SUV
i 1 1
Truck Minivan/Van Pickup
SUV
Fleet Average
Gasoline ICE
BEV/PHEV
Vehicle Type
Vehicle Weight and CO2 Emissions
Heavier vehicles require more energy to move than lower-weight vehicles and, if all other
factors are the same, will have lower fuel economy and higher CO2 emissions. Figure 3.8
shows estimated real-world CO2 emissions and fuel economy as a function of vehicle
inertia weight for several model year 2023 technologies. Increased weight correlates to
lower fuel economy and higher C02 emissions for ICE and hybrid technologies and may
also correlate for PHEVs. For BEVs, weight does not impact tailpipe emissions, since all BEVs
have zero tailpipe emissions, however increasing BEV weight likely correlates to reduced
vehicle efficiency, as measure in miles per gallon of gasoline equivalent (mpge). Limited
data did not allow for trendlines in Figure 3.8 for PHEV and BEV data.
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Figure 3.8. Relationship of Inertia Weight and CO2 Emissions
Gasoline ICE Gasoline ICE + Stop/Start
MHEV
HEV
PHEV
BEV
1000
(0
c
o
"to
w
'E
LU
O E
0 ra 500¦
CO
*
E
o
c
o
o
LU
£ CL
05
Inertia Weight (lbs)
~
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C. Vehicle Power
Vehicle power, measured in horsepower (hp), has changed dramatically since model year
1975. In the early years of this report, horsepower fell, from an average of 137 hp in model
year 1975 to 102 hp in model year 1981. Since model year 1981, however, horsepower has
increased almost every year. The average new vehicle in model year 2023 produced 94%
more power than a new vehicle in model year 1975, and 160% more power than an
average new vehicle in model year 1981. The average new vehicle horsepower is at a
record high, increasing from 259 hp in model year 2022 to 266 hp in model year 2023. The
preliminary value for model year 2024 is 267 hp, which would be another record-high for
horsepower.
Electric motors provide power differently than internal combustion engines. For example,
internal combustion engines need to achieve a high rotation speed (rotations per minute,
or RPM) before they can achieve maximum horsepower. In addition, many BEVs have high
hp ratings due to the large amount of power electric motors can generate. Determining the
overall vehicle horsepower for BEVs can be complicated for vehicles that have more than
one electric motor, depending on how the multiple motors are integrated. PHEVs, which
have an internal combustion engine, at least one motor, and complicated control
strategies, can be even more difficult to assess. Therefore, horsepower values for the
increasing number of BEVs and PHEVs may have higher uncertainty.
Vehicle Power by Vehicle Type
As with weight, the changes in horsepower are also different among vehicle types, as
shown in Figure 3.9. Horsepower for sedan/wagons increased 69% between model year
1975 and 2023,139% for car SUVs, 77% for truck SUVs, 72% for minivan/vans, and 141 % for
pickups. Horsepower has generally been increasing for all vehicle types since about 1985,
but there is more variation between model types in the last decade.
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Figure 3.9. Average New Vehicle Horsepower by Vehicle Type
ALL Sedan/Wagon Car SUV
350
300.
250-1
200-
150-
|> 100-
o
Q.
CD
CO
fe 350 -|
X
300-
250-
200-
150-
100-
/ 94%
Since MY 1975
Truck SUV
69% 1
Since MY 1975
139%
Since MY 1975
Minivan/Van
Pickup
77% 1
Since MY 1975
72% I
Since MY 1975
141% 1
Since MY 1975
1975 1985 1995 2005 2015 2025 1975 1985 1995 2005 2015 2025 1975 1985 1995 2005 2015 2025
Model Year
The distribution of horsepower over time has shifted towards vehicles with higher
horsepower, as shown in Figure 3.10. While few new vehicles in the early 1980s had greater
than 200 hp, the average vehicle in model year 2023 had 266 hp. In addition, vehicles with
more than 250 hp make up more than half of new vehicle production, and the maximum
horsepower for an individual vehicle is now 1,600 hp. Horsepower is projected to increase
again in model year 2024, with almost 10% of vehicles projected to reach 400 hp or higher.
a
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Figure 3.10. Horsepower Distribution by Model Year
1975 1985 1995 2005 2015 2025
Model Year
Horsepower
¦
>450
400-450
¦
350-400
300-350
¦
250-300
200-250
¦
150-200
100-150
50-100
¦
0-50
Vehicle Power and Technology
Electric vehicles utilize an electric motor, instead of a gasoline internal combustion engine,
to move the vehicle. Electric motors have the advantage of having maximum torque
available from a standstill and can be used to create vehicles with high horsepower. Figure
3.11 shows the average horsepower, by vehicle type, of internal combustion engine (ICE)
vehicles (including those with stop start, but not hybrids or PHEVs) compared to PHEVs and
BEVs. For each of the four most popular vehicle types, PHEVs and BEVs have higher
horsepower than their ICE counterparts. For minivan/vans, the average PHEV and BEV have
lower horsepower, but there are also limited vehicles available to compare. The average of
all vehicles within each vehicle type is also shown. PHEVs and BEVs do appear to be
increasing the overall horsepower within each vehicle type (except for minivan/vans - in
part due perhaps to very limited offerings within this vehicle type) with the overall impact
dependent on the uptake of PHEVs and BEVs within each vehicle type.
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Figure 3.11. Average New Vehicle Horsepower by Vehicle Type and Powertrain
500
400
300
CD
I
CL
CD
CO
x 200
100
0
E
f'/
w,
Sedan/Wagon Car
SUV
Truck Minivan/Van Pickup
SUV
Vehicle Type
Fleet Average
Gasoline ICE
BEV/PHEV
Vehicle Power and CO2 Emissions
As with weight, higher horsepower vehicles are generally less efficient and have higher CO2
emissions, if all other factors are the same. However, the relationship between vehicle
power, CO2 emissions, and fuel economy has become more complex as new technology
and vehicles have emerged in the marketplace. Figure 3.12, shows estimated real-world
CO2 emissions and fuel economy as a function of vehicle horsepower for several model
year 2023 technologies. Increased horsepower correlates to lower fuel economy and
higher CO2 emissions for ICE, hybrid, and PHEV vehicles. For BEVs, horsepower does not
impact tailpipe emissions, since all BEVs have zero tailpipe emissions, however the
relationship between increasing BEV horsepower and vehicle efficiency, as measure in
miles per gallon of gasoline equivalent (mpge), is less clear. Limited data did not allow for
trendlines in Figure 3.12 for BEV data.
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Figure 3.12. Relationship of Horsepower and CO2 Emissions
Gasoline ICE Gasoline ICE + Stop/Start MHEV
HEV
LU
1000
750-
O E
0 o) 500-
a.
>>
E
O
C
o
o
LU
§ O
if 0-
2 1-
1
o
250
0
100
50
CD
-------
Vehicle Acceleration
Vehicle acceleration is closely related to vehicle horsepower. As new vehicles have
increased horsepower, the corresponding ability of vehicles to accelerate has also
increased. The most common vehicle acceleration metric, and one of the most recognized
vehicle metrics overall, is the time it takes a vehicle to accelerate from 0-to-60 miles per
hour, also called the 0-to-60 time. Data on 0-to-60 times are not directly submitted to EPA
but are calculated for most vehicles using vehicle attributes and calculation methods
developed by MacKenzie and Heywood (2012).8
The relationship between power and acceleration is different for BEVs than for vehicles
with internal combustion engines. Electric motors generally have maximum torque
available from a standstill, which is not true for internal combustion engines. The result is
that BEVs can have very fast 0-to-60 acceleration times, and the calculation methods used
for vehicles with internal combustion engines are not valid for BEVs. PHEVs and hybrids
may also use their motors to improve acceleration. Acceleration times for BEVs, PHEVs, and
hybrids must be obtained from external sources, and as with horsepower values for these
vehicles, there may be more uncertainty with these values.
Since the early 1980s, there has been a clear downward trend in 0-to-60 times. Figure 3.13
shows the average new vehicle 0-to-60 time since model year 1978. The average new
vehicle in model year 2023 had a 0-to-60 time of 7.3 seconds, which is the fastest average
0-to-60 time for any model year and less than half of the average 0-to-60 time of the early
1980s. The calculated 0-to-60 time for model year 2024 is projected to increase slightly to
7.4 seconds. The long-term downward trend in 0-to-60 times is consistent across all vehicle
types. Increasing BEV production will likely continue, and perhaps increase, the trend
towards lower 0-to-60 acceleration times.
8 MacKenzie, D. Heywood, J. 2012. Acceleration performance trends and the evolving relationship among
power, weight, and acceleration in U.S. light-duty vehicles: A linear regression analysis. Transportation Research
Board, Paper NO 12-1475, TRB 91st Annual Meeting, Washington, DC, January 2012.
a
a
34
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Figure 3.13. Calculated 0-to-60 Time by Vehicle Type
18 H
15-
12-
9-
C/)
c 1
o
o
5 18H
15-
12-
9-
ALL
Truck SUV
-43% ~
Since MY 1978
Sedan/Wagon
-46%
Since MY
1
1978
~\ 1 1 1 1 r
-46% ~
Since MY 1978
Minivan / Van
-43% ~
Since MY 1978
t 1 1 1 1 r
Car SUV
-50% ~
Since MY 1978
Pickup
-50%
Since MY 1978
4
1975 1985 1995 2005 2015 20251975 1985 1995 2005 2015 20251975 1985 1995 2005 2015 2025
Model Year
D. Vehicle Footprint
Vehicle footprint is an important attribute since it is the basis for the current C02 emissions
and fuel economy standards. Footprint is the product of wheelbase times average track
width (the area defined by where the centers of the tires touch the ground). This report
provides footprint data beginning with model year 2008, although footprint data from
model years 2008-2010 were aggregated from various sources and EPA has less
confidence in the precision of these data than that of formal compliance data. Beginning in
model year 2011, the first year when both car and truck CAFE standards were based on
footprint, automakers began to submit reports to EPA with footprint data at the end of the
model year, and these official footprint data are reflected in the final data through model
year 2023. EPA projects footprint data for the preliminary model year 2024 fleet based on
footprint values from the previous model year and, for new vehicle designs, publicly
available data.
a J 35
5 0 JJ
u
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Vehicle Footprint by Vehicle Type
Figure 3.14 shows overall new vehicle and vehicle type footprint data since model year
2008. Between model year 2008 and 2023, the overall average footprint increased 6%, from
48.9 to 51.8 square feet. All five vehicle types have increased average footprint since model
year 2008, with sedan wagons increasing 4.9%, Car SUVs and minivans/vans increasing
4.5%, truck SUVs increasing 3.7%, and pickups increasing 3.4%. This increase, which is
larger than the increase within any individual vehicle type, was impacted by both the trends
within each vehicle type and the changing mix of vehicles over time, as the market has
shifted towards larger vehicles.
Figure 3.14. Footprint by Vehicle Type for Model Years 2008-2023
70-
60-
o
o
50-
40-
Pickup
Fleetwide Average
Car SUV
Sedan/Wagon
2008
2010
2012
2014
2016
2018
2020
2022
2024
Model Year
The distribution of footprints across all new vehicles, as shown in Figure 3.15, also shows a
slow reduction in the number of smaller vehicles with a footprint of less than 45 square
feet, along with growth in larger vehicle categories. This is consistent with the changes in
market trends towards larger vehicles, as seen in Figure 3.2 and elsewhere in this report.
Projected data for model year 2024 suggest that overall average footprint will decrease
slightly to 51.6 square feet.
q J 36
5 0 JO
u
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Figure 3.15. Footprint Distribution by Model Year
100%-
75% -
50% -
25% -
0% -
2008
2010
2012
2014
2016
2018
2020
2022
2024
Model Year
Footprint
>65
J 60-65
55-60
H 50-55
45-50
40-45
<40
Vehicle Footprint and Technology
Figure 3.16 shows the average footprint, by vehicle type, of internal combustion engine
(ICE) vehicles (including those with stop start, but not hybrids or PHEVs) compared to BEVs
and PHEVs. For all vehicle types, BEVs and PHEVs have slightly larger footprints than their
ICE counterparts. The average of all vehicles within each vehicle type is also shown, with
the overall impact dependent on the uptake of BEVs and PHEVs within each vehicle type.
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Figure 3.16. Average New Vehicle Footprint by Vehicle Type and Powertrain
70
60
50
cr
« 40
CL
o
o
30
20
10
0
Fleet Average
Gasoline ICE
BEV/PHEV
Sedan/Wagon Car
SUV
Truck Minivan/Van Pickup
SUV
Vehicle Type
Vehicle Footprint and CO2 Emissions
Vehicles with a larger footprint are likely to weigh more and have more frontal area, which
leads to increased aerodynamic resistance. Increased weight and aerodynamic resistance
increase CO2 emissions and decrease fuel economy. Figure 3.17 shows estimated real-
world CO2 emissions and fuel economy as a function of vehicle footprint for several model
year 2023 technologies. Increased footprint correlates to lower fuel economy and higher
C02 emissions for ICE and hybrid technologies and may also correlate for PHEVs. For BEVs,
footprint does not impact tailpipe emissions, since all BEVs have zero tailpipe emissions,
however increasing BEV footprint likely correlates to reduced vehicle efficiency, as measure
in miles per gallon of gasoline equivalent (mpge). Limited data did not allow for trendlines
in Figure 3.17 for PHEV and BEV data.
~
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Figure 3.17. Relationship of Footprint and CO2 Emissions
Gasoline ICE Gasoline ICE + Stop/Start
MHEV
V)
c
o
LU
CD
a>
>s
E
o
c
o
o
LU
£ Q-
(0
d>
Cd
1000
750-
CM
O E
0 o) 500'
250
0
100
50
im
40 50 60 70
40 50 60 70
HEV
A
l!^
40 50 60 70 40 50 60 70
Footprint (sq. ft.)
PHEV
BEV
40 50 60 70
40 50 60 70
39
-------
E. Vehicle Type and Attribute Tradeoffs
The past 50 years of data show striking changes in the mix of vehicle types, and the
attributes of those vehicles, produced for sale in the United States. Between 1975 and the
early 1980s, average new vehicle fuel economy increased rapidly, while the vehicle weight
and horsepower fell. For the next twenty years, average new vehicle weight and
horsepower steadily increased, while fuel economy steadily decreased. Model year 2004
was another inflection point, after which fuel economy, horsepower, and weight have all
generally increased together, to historic highs in model year 2023. Since model year 2004,
average new vehicle fuel economy has increased 40%, horsepower increased 26%, and
weight increased 6%. Footprint has increased 6% since EPA began tracking it in model year
2008. Fuel economy, weight, and horsepower are all projected to increase again in model
year 2024, as shown in Figure 3.18.
The changes within each of these metrics is due to the combination of design and
technology changes within each vehicle type, as well as the market shifts between vehicle
types. For example, overall new vehicle footprint has increased within each vehicle type
since model year 2008, but the average new vehicle footprint has increased more than the
increase in any individual vehicle type over that time span, due to market shifts towards
larger vehicle types. Fuel economy has also increased in all vehicle types since model year
2008, however the market shift towards less efficient vehicle types has offset some of the
fleetwide fuel economy and CO2 emission benefits that otherwise would have been
achieved through improving technology.
Vehicle fuel economy and CO2 emissions are clearly related to vehicle attributes
investigated in this section, namely weight, horsepower, and footprint. Future trends in fuel
economy and CO2 emissions will be dependent, at least in part, by design choices related to
these attributes.
~
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Figure 3.18. Relative Change in Fuel Economy, Weight, Horsepower, and
Footprint
m
G)
0
o
c
W
0
O)
c
CO
_c
O
100%
75%
50%
25%
0%
-25%
Real-World Fue
Economy
/
Horsepower
Weight
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
CO
o
o
C\l
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Table 3.1. Vehicle Attributes by Model Year
Model Year
Real-World
co2
(g/mi)
Real-World
FE
(mpg)
Weight
(lbs)
Horsepower
(HP)
0 to 60
(s)
Footprint
(ft2)
Car
Production
Share
Truck
Production
Share
1975
681
13.1
4,060
137
-
-
80.7%
19.3%
1980
466
19.2
3,228
104
15.6
-
83.5%
16.5%
1985
417
21.3
3,271
114
14.1
-
75.2%
24.8%
1990
420
21.2
3,426
135
11.5
-
70.4%
29.6%
1995
434
20.5
3,613
158
10.1
-
63.5%
36.5%
2000
450
19.8
3,821
181
9.8
-
58.8%
41.2%
2005
447
19.9
4,059
209
9.0
-
55.6%
44.4%
2010
394
22.6
4,001
214
8.8
48.5
62.8%
37.2%
2011
399
22.3
4,126
230
8.5
49.5
57.8%
42.2%
2012
377
23.6
3,979
222
8.5
48.8
64.4%
35.6%
2013
368
24.2
4,003
226
8.4
49.1
64.1%
35.9%
2014
369
24.1
4,060
230
8.3
49.7
59.3%
40.7%
2015
360
24.6
4,035
229
8.3
49.4
57.4%
42.6%
2016
359
24.7
4,035
230
8.3
49.5
55.3%
44.7%
2017
357
24.9
4,093
234
8.2
49.8
52.6%
47.4%
2018
353
25.1
4,137
241
8.0
50.4
48.0%
52.0%
2019
356
24.9
4,156
245
7.9
50.8
44.4%
55.6%
2020
349
25.4
4,166
246
7.8
50.9
43.9%
56.1%
2021
347
25.4
4,289
253
7.7
51.5
37.1%
62.9%
2022
337
26.0
4,303
259
7.6
51.6
36.9%
63.1%
2023
319
27.1
4,371
266
7.3
51.8
37.5%
62.5%
2024 (prelim)
305
28.0
4,419
267
7.4
51.6
36.7%
63.3%
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
~
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Table 3.2. Estimated Real-World Fuel Economy and CO2 by Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
Pickup
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
World
World
World
World
World
World
World
World
World
World
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Model Year
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
1975
80.6%
660
13.5
0.1%
799
11.1
1.7%
806
11.0
4.5%
800
11.1
13.1%
746
11.9
1980
83.5%
446
20.0
0.0%
610
14.6
1.6%
676
13.2
2.1%
629
14.1
12.7%
541
16.5
1985
74.6%
387
23.0
0.6%
443
20.1
4.5%
538
16.5
5.9%
537
16.5
14.4%
489
18.2
1990
69.8%
381
23.3
0.5%
472
18.8
5.1%
541
16.4
10.0%
498
17.8
14.5%
511
17.4
1995
62.0%
379
23.4
1.5%
499
17.8
10.5%
555
16.0
11.0%
492
18.1
15.0%
526
16.9
2000
55.1%
388
22.9
3.7%
497
17.9
15.2%
555
16.0
10.2%
478
18.6
15.8%
534
16.7
2005
50.5%
379
23.5
5.1%
440
20.2
20.6%
531
16.7
9.3%
460
19.3
14.5%
561
15.8
2010
54.5%
340
26.2
8.2%
386
23.0
20.7%
452
19.7
5.0%
442
20.1
11.5%
527
16.9
2011
47.8%
344
25.8
10.0%
378
23.5
25.5%
449
19.8
4.3%
424
20.9
12.3%
516
17.2
2012
55.0%
322
27.6
9.4%
381
23.3
20.6%
445
20.0
4.9%
418
21.3
10.1%
516
17.2
2013
54.1%
313
28.4
10.0%
365
24.3
21.8%
427
20.8
3.8%
422
21.1
10.4%
509
17.5
2014
49.2%
313
28.4
10.1%
364
24.4
23.9%
412
21.6
4.3%
418
21.3
12.4%
493
18.0
2015
47.2%
306
29.0
10.2%
353
25.1
28.1%
406
21.9
3.9%
408
21.8
10.7%
474
18.8
2016
43.8%
303
29.2
11.5%
338
26.2
29.1%
400
22.2
3.9%
410
21.7
11.7%
471
18.9
2017
41.0%
293
30.2
11.6%
339
26.1
31.7%
398
22.3
3.6%
399
22.2
12.1%
470
18.9
2018
36.7%
286
30.8
11.3%
324
27.4
35.0%
384
23.1
3.1%
389
22.8
13.9%
466
19.1
2019
32.7%
285
30.9
11.7%
323
27.5
36.5%
378
23.5
3.4%
396
22.4
15.6%
467
19.0
2020
30.9%
277
31.7
13.0%
310
28.4
38.7%
374
23.8
2.9%
379
23.4
14.4%
465
19.2
2021
25.7%
270
32.2
11.4%
278
31.0
44.7%
368
24.1
2.2%
322
27.3
16.1%
463
19.3
2022
26.5%
260
33.2
10.4%
250
33.4
43.8%
364
24.2
2.9%
339
26.0
16.4%
444
20.0
2023
25.0%
249
34.1
12.5%
190
40.5
45.3%
356
24.7
2.5%
339
25.9
14.7%
432
20.5
2024 (prelim)
21.3%
248
34.3
15.4%
190
40.3
46.6%
333
26.0
1.8%
332
26.3
14.9%
418
21.0
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
~
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Table 3.3. Model Year 2023 Vehicle Attributes by Manufacturer
Real-World
Real-World
co2
FE
Weight
Horsepower
0-to-60
Footprint
Manufacturer
(g/mi)
(mpg)
(lbs)
(HP)
(s)
(ft2)
BMW
305
27.6
4600
321
6.0
50.2
Ford
374
23.2
4845
316
6.6
58.2
GM
396
22.4
4766
288
7.3
55.7
Honda
314
28.3
3936
212
7.7
49.4
Hyundai
292
29.8
3824
206
8.1
48.7
Kia
289
30.4
3721
191
8.3
47.9
Mazda
322
27.6
3864
196
8.9
46.7
Mercedes
304
27.5
4843
306
6.4
52.3
Nissan
305
28.9
4075
222
8.3
48.4
Stellantis
402
21.8
4836
316
7.0
56.0
Subaru
311
28.4
3939
198
9.0
46.0
Tesla
0
120.6
4384
407
4.6
50.7
Toyota
322
27.5
4227
231
7.7
50.4
VW
317
27.0
4361
263
7.0
48.8
Other
276
29.1
4940
352
6.6
50.8
All Manufacturers
319
27.1
4371
266
7.3
51.8
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
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Table 3.4. Model Year 2023 Estimated Real-World Fuel Economy and CO2 by Manufacturer and Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
Pickup
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
Real-
World
World
World
World
World
World
World
World
World
World
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Prod
C02
FE
Manufacturer
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
Share
(g/mi)
(mpg)
BMW
46.6%
268
31.0
4.7%
342
26.0
48.7%
338
25.2
-
-
-
-
-
-
Ford
1.3%
408
21.8
8.4%
135
47.5
44.7%
401
22.1
1.6%
351
25.3
44.0%
392
22.2
GM
14.5%
252
32.5
11.6%
301
29.4
48.6%
422
21.1
-
-
-
25.3%
474
19.0
Honda
42.5%
267
33.3
7.3%
269
33.0
35.3%
344
25.9
8.0%
377
23.6
6.9%
424
21.0
Hyundai
33.9%
246
35.4
27.1%
262
32.1
39.1%
352
25.2
-
-
-
-
-
-
Kia
45.3%
242
35.7
9.9%
300
29.6
41.9%
330
26.7
2.9%
386
23.0
-
-
-
Mazda
11.3%
285
31.1
-
-
-
88.7%
327
27.2
-
-
-
-
-
-
Mercedes
34.6%
297
28.6
16.2%
129
48.0
40.0%
357
24.0
9.2%
411
21.6
-
-
-
Nissan
38.5%
257
33.6
16.3%
268
33.2
36.5%
339
26.2
-
-
-
8.7%
447
19.9
Stellantis
15.2%
425
20.9
0.0%
329
27.0
50.8%
382
22.7
10.2%
334
25.6
23.8%
458
19.5
Subaru
13.5%
321
27.6
-
-
-
86.5%
310
28.5
-
-
-
-
-
-
Tesla
36.1%
0
126.8
55.1%
0
117.1
8.8%
0
118.5
-
-
-
-
-
-
Toyota
29.4%
258
34.4
8.6%
284
31.0
39.7%
329
26.8
3.1%
249
35.7
19.1%
435
20.4
VW
25.3%
310
28.0
13.8%
203
38.6
60.9%
345
25.0
-
-
-
-
-
-
Other
11.3%
182
40.7
8.7%
88
54.4
76.1%
323
26.0
0.5%
331
26.9
3.5%
0
69.4
All Manufacturers
25.0%
249
34.1
12.5%
190
40.5
45.3%
356
24.7
2.5%
339
25.9
14.7%
432
20.5
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
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Table 3.5. Footprint by Manufacturer for Model Year 2022-2024 (ft2)
Manufacturer
Final MY 2022
Final MY 2023
Preliminary MY2024
Car
Truck
All
Car
Truck
All
Car
Truck
All
BMW
48.3
52.8
50.5
48.6
52.0
50.2
48.8
52.1
50.5
Ford
48.1
56.9
55.9
49.2
59.2
58.2
48.0
57.8
56.4
GM
46.1
59.3
56.0
46.4
59.0
55.7
46.3
59.6
55.0
Honda
46.3
50.4
48.3
46.9
51.9
49.4
46.6
50.9
48.4
Hyundai
46.9
50.3
48.3
47.6
50.3
48.7
47.8
50.8
49.2
Kia
46.6
51.2
48.8
46.2
50.0
47.9
47.0
51.3
49.4
Mazda
44.2
46.7
46.3
44.0
47.0
46.7
44.4
47.1
46.9
Mercedes
50.6
53.4
52.2
50.7
53.9
52.3
51.3
53.0
52.1
Nissan
46.6
52.9
49.1
46.6
50.6
48.4
46.6
51.6
48.9
Stellantis
51.5
57.5
56.7
52.8
56.6
56.0
42.0
56.0
55.7
Subaru
45.2
46.5
46.3
45.0
46.2
46.0
45.4
46.1
46.0
Tesla
50.7
51.7
50.8
50.7
51.5
50.7
50.8
51.1
50.8
Toyota
46.5
52.0
49.7
46.9
52.6
50.4
46.5
53.6
51.3
VW
46.2
50.1
48.6
46.5
50.3
48.8
46.7
50.3
49.2
Other
45.7
51.1
49.2
47.4
51.6
50.8
47.5
53.4
52.1
All Manufacturers
47.2
54.2
51.6
47.7
54.2
51.8
47.5
54.0
51.6
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
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4. Vehicle Technology
Since model year 1975, the technology used in vehicles has continually evolved. Today's
vehicles utilize an increasingly wide array of technological solutions developed by the
automotive industry to improve vehicle attributes discussed previously in this report,
including CO2 emissions, fuel economy, vehicle power, and acceleration. Automotive
engineers and designers are constantly creating and evaluating new technology and
deciding how, or if, it should be applied to their vehicles. This section of the report looks at
vehicle technology from two perspectives; first, how the industry has adopted specific
technologies over time, and second, how those technologies have impacted CO2 emissions
and fuel economy.
Vehicle Architecture
All vehicles use some type of engine or motor to convert energy stored on the vehicle,
usually in a fuel or battery, into rotational energy to propel the vehicle forward. The
generalized vehicle architecture for a vehicle with a gasoline internal combustion engine
(ICE) is shown in Figure 4.1. Internal combustion engines typically combust gasoline or
diesel fuel to rotate an output shaft. The engine is paired with a transmission to convert the
rotational energy from the relatively narrow range of speeds available at the engine to the
appropriate speed required for driving conditions. The transmission is connected to a
driveline that transfers the rotational energy from the transmission to the two or four
wheels being used to move the vehicle. Each of these components has energy losses, or
inefficiencies, which ultimately increase vehicle CO2 emissions and decrease fuel economy.
Figure 4.1. Vehicle Energy Flow for an Internal Combustion Engine Vehicle
*
Tires
I
Engine
1
Transmission J
I
Driveline
m h
-------
The general vehicle design shown in Figure 4.1 was nearly universal in the automotive
industry for decades, but more recent technology developments have created vehicle
architectures that look quite different.
Vehicles that have stop/start systems generally use a larger alternator and enhanced
battery, which enables the vehicle to turn off the engine at idle to save fuel. Hybrid vehicles
use a larger battery to recapture braking energy and provide traction power when
necessary, allowing for a smaller, more efficiently operated engine. Hybrids can be
separated into smaller "mild" hybrid systems (MHEVs) that provide launch assist but cannot
propel the vehicle on their own, and "strong" hybrid systems (HEVs) that can temporarily
power the vehicle without engaging the engine. Plug-in hybrid vehicles (PHEV) have both a
battery that can be charged from an external electricity source and a gasoline engine and
operate on electricity until the battery is depleted or cannot meet driving needs. Strong
hybrids and PHEVs often have much more complicated architectures that allow for
complex energy optimization strategies that ultimately improve some combination of
vehicle C02 emission, fuel economy, and vehicle performance. These vehicles use a
combination of an engine and one or more motors to power the wheels, and recapture
braking energy.
Full battery electric vehicles (BEVs) employ a battery pack that is externally charged and an
electric motor exclusively for propulsion, and do not have an onboard gasoline engine.
BEVs can have very simple layouts, as vehicles with one electric motor can be directly
connected to the driveline without a traditional transmission.9 However, some
manufacturers are producing electric vehicles with 2-speed transmissions, and others have
developed vehicles with 2 or more motors that propel the vehicle in combination.
Vehicles with diesel engines are also present in the light-duty automotive market, and
briefly reached 6% of all production in model year 1981. Vehicles relying on the combustion
of a fuel other than gasoline or diesel, such as compressed natural gas (CNG), have
occasionally been produced for sale in the U.S. Fuel cell electric vehicles (FCEVs) which use
a fuel cell stack to create electricity from an onboard fuel source (usually hydrogen) to
power a motor, have also been produced in recent years. These vehicles are included in the
data for this report, but generally have not been produced in large volumes.10
9 For more information on electric vehicles, see EPA's Green Vehicle Guide (https://www.epa.gov/greenvehicles)
or the U.S. Department of Energy's Alternative Fuels Data Center (https://afdc.energy.gov/vehicles/how-do-all-
electric-cars-workl or www.fueleconomy.gov(https://fueleconomy.gov/feg/evtech.shtml)
10 Vehicles converted to an alternative fuel in the aftermarket are not included in this data.
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Overall Industry Trends
Innovation in the automobile industry has led to a wide array of technology available to
manufacturers to achieve C02 emissions, fuel economy, and performance goals. Figure 4.2
illustrates manufacturer-specific technology usage for model year 2023 for technologies
that represent increasing levels of vehicle electrification, as well as the recent adoption
trends of those technologies across the industry. The technologies in Figure 4.2 are being
used by manufacturers, in part, to reduce C02 emissions and increase fuel economy.
Manufacturers' strategies to develop and adopt these technologies are unique and vary
significantly. Each manufacturer is choosing technologies that best meet the design
requirements of their vehicles. In model year 2023, gasoline vehicles with stop/start,
MHEVs, HEVs, PHEVs, and BEVs all gained market share and captured their largest market
shares on record.
In addition to electrification technologies, other technologies continue to improve the
performance of internal combustion engines (ICE), including the engines found in hybrids
and PHEVS. These technologies include a combination of turbocharged engines (Turbo),
gasoline direct injection (GDI), fuel injection systems that can alternate between GDI or port
fuel injection (GDPI), and cylinder deactivation (CD). Higher speed transmissions and
continuous variable transmissions (CVT) also enable the engine to operate in the most
efficient way possible. Table 4.1 shows the implementation of several of these
technologies, as used in conjunction with the electrification technologies identified in
Figure 4.2.
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Figure 4.2. Manufacturer Use of Electrification Technologies for Model Year 2023
100%-
75%-
-------
Table 4.1. Production Share by Drive Technology for Model Year 2023
Gasoline
Gasoline
Mild
Strong
Plug-In
Battery
Fuel
ICE without
ICE with
Hybrid
Hybrid
Hybrid
Electric
Cell
Technology
Diesel
Stop/Start
Stop/Start
(MHEV)
(HEV)
(PHEV)
(BEV)
(FCEV)
All
Production
Share
0.8%
26.3%
49.2%
4.9%
7.2%
1.7%
9.8%
0.0%
100.0%
Stop/Start
95.0%
-
100.0%
100.0%
100.0%
100.0%
-
-
63.8%
GDI
-
36.2%
67.7%
68.0%
43.1%
68.7%
-
-
50.5%
GDPI
-
34.3%
20.6%
3.2%
46.8%
13.5%
-
-
22.9%
Turbo
100.0%
21.4%
52.6%
58.5%
23.9%
66.0%
-
-
38.0%
7+ Gears
100.0%
44.1%
75.9%
100.0%
10.6%
56.6%
-
-
56.4%
CVT
-
31.7%
21.4%
-
69.6%
28.8%
-
-
24.4%
Average Fuel
Economy
24.1
24.9
24.0
23.0
36.4
36.8
106.7
70.1
27.1
(mpge)
Average GHG
Emissions
422
357
370
387
244
174
0
0
319
(g/mi)
Average #
Cylinders
6
4.9
4.9
5.7
4.2
4.4
-
-
4.9
Figure 4.3. shows the current adoption rates of electrification and engine improvement
technologies for the fourteen largest manufacturers. The technologies in Figure 4.3. have
emerged as significant technology developments within the last 10-15 years (some, like
turbocharged engines, were available before this timeframe, but in small numbers).
Manufacturers are continuing to implement both electrification and engine technology
improvements across their vehicles to improve CO2 emissions, fuel economy, and
performance.
The following sections provide a deeper look into many of the technology trends identified
here, beginning with engine/propulsion technologies, then transmissions, and drivelines.
While the evolution of vehicles in more recent years challenges the breakdown of
technology into these traditional categories, it is still a useful context for evaluating
different aspects of vehicle technology and the many changes taking place across the
automotive industry.
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Figure 4.3. Manufacturer Use of Emerging Technologies for Model Year 2023
Tesla -
Kia -
Hyundai -
Nissan -
Subaru -
Honda -
BMW -
Mazda -
Toyota -
Mercedes -
VW-
Ford-
GM-
Stellantis -
All Manufacturers -
26%
63%
34%
50%
52%
25%
70%
23%
59%
37%
41%
82%
74%
23%
43%
25%
98%
91%
74%
31%
81%
33%
60%
38%
72%
90%
90%
89%
49%
21%
100%
76%
5%
18%
87%
33%
43%
26%
75%
81%
4%
81%
33%
78%
88%
3%
86%
59%
75%
83%
6%
5%
88%
58%
49%
91%
56%
11%
78%
87%
23%
19%
19%
2%
97%
51%
38%
73%
15%
24%
56%
49%
0%
11%
10%
18%
28%
24%
38%
25%
8%
17%
5%
7%
2%
1%
0%
8%
2%
0%
1%
1%
9%
2%
1 1 1
Turbo GDI or Cylinder
GDPI Deactivation
i 1 1 1
CVT 7+ Non-Hybrid MHEV
Gears StopStart
HEV
1
PHEV
100%
3%
7%
3%
2%
10%
0%
1%
19%
12%
7%
4%
10%
0%
0%
0%
BEV
i
FCEV
0
a
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A. Vehicle Propulsion
As discussed above, all vehicles use at least one engine or motor to convert stored energy
into rotational energy to propel the vehicle forward. Over the 50 years that EPA has been
collecting data, the technology used in engines, and now motors, has continually evolved.
The industry continues to develop new and innovative technologies to improve vehicle
efficiency, reduce emissions, and increase vehicle performance and features. The following
analysis will look at technology trends within gasoline engine vehicles, hybrids, PHEVs and
EVs, and diesels. Each of these categories of engine technologies has unique properties,
metrics, and trends over time.
Gasoline Engines
Since EPA began tracking vehicle data in 1975, nearly 700 million vehicles have been
produced for sale in the United States. While electric vehicles have been capturing a
growing share of the market in recent years, as shown in Figure 4.2, vehicles with gasoline
engines still make up most of the market today and in past years have often been nearly
the only option available.
The following analysis focuses on engine technology and metrics for gasoline engines.
Hybrid and plug-in hybrid vehicles are included in this data unless they are explicitly
excluded. For the purposes of this report "flex fuel" vehicles that are capable of operating
on gasoline or a blend of 85% ethanol and 15% gasoline (E85) are included with gasoline
engines and are not evaluated seperately.
Engine Size and Displacement
Measuring and tracking new vehicle engine size is one of the most basic, and important
ways to track engine trends, because larger engines strongly correlate with higher fuel use.
Engine size is a generally described in one of two ways, either the number of cylinders or
the total displacement of the engine (the total volume of the cylinders). Figure 4.4 shows
the production share of gasoline engines by number of cylinders over time.
In the mid and late 1970s, the 8-cylinder gasoline engine was dominant, accounting for well
over half of all new vehicle production. Between model year 1979 and 1980, there was a
significant change in the market, as 8-cylinder engine production share dropped, as larger
engines were replaced with smaller 4-cylinder and some 6-cylinder engines. From model
year 1987 through 2004, production moved back towards larger 6-cylinder and 8-cylinder
53
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engines. This trend reversed again in 2005 as production began trending back towards 4-
cylinder engines. Four-cylinder gasoline engines are the most popular engine option,
capturing about 51 % of the market in model year 2023.
Figure 4.4. Gasoline Engine Production Share by Number of Cylinders
100%.
0
!
TO
_C
(J)
c
o
"8
T3
O
75% ¦
50% ¦
25% ¦
0%-
l 1 1 1 1 1 1 1 1 1 r
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Cylinders
Less than 4
4 Cylinder
I 5 Cylinder
I 6 Cylinder
8 Cylinder
I More than 8
Overall engine size, as measured by the total volume of all the engine's cylinders, is directly
related to the number of cylinders. As vehicles have moved towards engines with a lower
number of cylinders, the total engine size, or displacement, is also at an all-time low. The
average new vehicle in model year 1975 had a displacement of nearly 300 cubic inches (or
just under 5 liters), compared to an average of 170 cubic inches (about 2.8 liters) in model
year 2023. Gasoline engine displacement per cylinder has been relatively stable over the
time of this report (around 35 cubic inches, or 0.6 liters, per cylinder since 1980), so the
reduction in overall new vehicle engine displacement is almost entirely due to the shift
towards engines with fewer cylinders.
Even as gasoline engine displacement has fallen over time, horsepower has generally
increased. One way to examine the relationship between gasoline engine horsepower and
a
a
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displacement is to look at the trend in specific power (HP/Displacement), which is a metric
to compare the power output of an engine relative to its size. Specific power has doubled
between model year 1975 and model year 2023. The rate at which specific power has
increased has been remarkably steady, as shown in Figure 4.5. The specific power of new
vehicle gasoline engines (excluding hybrids and PHEVS) has increased by about 0.02
horsepower per cubic inch every year for 50 years. Considering the numerous and
significant changes to engines over this time span, changes in consumer preferences, and
the external pressures on vehicle purchases, the long-standing linearity of this trend is
noteworthy. The roughly linear increase in specific power does not appear to be slowing.
Turbocharged engines, direct injection, higher compression ratios, and many other engine
technologies are likely to continue increasing engine specific power.
Figure 4.5 also shows two other important engine metrics, the amount of fuel consumed
compared to the overall size of the engine (Fuel Consumption/Displacement), and the
amount of fuel consumed relative to the amount of power produced by an engine (Fuel
Consumption/HP). For Figure 4.5, gasoline engines in hybrids and PHEVs have been
excluded. The amount of fuel consumed by a gasoline engine in model year 2023, relative
to the total displacement, is about 11 % lower than in model year 1975. Fuel consumption
relative to engine horsepower has fallen more than 70% since model year 1975. Taken as a
whole, the trend lines in Figure 4.5 clearly show that gasoline engine improvements over
time have been steady and continual and have resulted in impressive improvements to
internal combustion engines.
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Figure 4.5. Percent Change for Specific Gasoline Non-Hybrid Engine Metrics
200% -
150%
LO
£ 100%'
-------
engines (GDPI), as shown in Figure 4.6. TBI and PFI systems use fuel injectors to
electronically deliver fuel and mix it with air outside of the engine cylinder; the resulting air
and fuel mixture is then delivered to the engine cylinders for combustion. Engines that
utilize GDI spray fuel directly into the air in the engine cylinder for better control of the
combustion process. Engines using GDI were first introduced into the market with very
limited production in model year 2007. The use of GDI has increased in subsequent years
to the point where 74% of the model year 2023 fleet had either GDI or GDPI. In model year
2023, GDI engines were installed in 51 % of model year 2023 vehicles, while GDPI engines
were installed in 23% of new vehicles.
Another key aspect of engine design is the valvetrain. Each engine cylinder must have a set
of valves that allow for air (or an air/fuel mixture) to flow into the engine cylinder prior to
combustion and for exhaust gases to exit the cylinder after combustion. The number of
valves per cylinder and the method of controlling the valves (i.e., the valvetrain) directly
impacts the overall efficiency of the engine. Generally, engines with four valves per cylinder
instead of two, and valvetrains that can alter valve timing during the combustion cycle can
provide more precise control of the combustion process and therefore increase engine
power and efficiency.
This report began tracking multi-valve engines (i.e., engines with more than two valves per
cylinder) for cars in model year 1986 and for trucks in model year 1994. Since that time,
about 90% of the fleet has converted to multi-valve design. While some three- and five-
valve engines have been produced, the majority of multi-valve engines are based on four
valves per cylinder. Engines with four valves generally use two valves for air intake and two
valves for exhaust. In addition, this report began tracking variable valve timing (VVT)
technology for cars in model year 1990 and for trucks in model year 2000, and since then
nearly the entire fleet has adopted this technology. Figure 4.6 shows the evolution of
engine technology, including fuel delivery method and the introduction of VVT and multi-
valve engines.
As shown in Figure 4.6, fuel delivery and valvetrain technologies have often been
developed simultaneously. Nearly all carbureted engines relied on fixed valve timing and
had two valves per cylinder, as did early port-injected engines. Port-injected engines largely
developed into engines with both multi-valve and WT technology. Engines with GDI are
almost exclusively using multi-valve and WT technology. These four engine groupings, or
packages, represent a large share of the engines produced over the timespan covered by
this report.
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Figure 4.6. Production Share by Engine Technology
£
CO
_£Z
cn
c
o
o
3
T3
O
100% -
75% -
50% -
25% -
0%
100%
75% -
50% -
25% -
0%-
14
13-
Car
12
P
10
9"
.15
-14
Truck
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Fuel Delivery
Valve Timing
Number of Valves
Key
Carbureted
Fixed
Two-Valve
1
Multi-Valve
2
Throttle Body Injection
Fixed
Two-Valve
3
Multi-Valve
4
Port Fuel Injection
Fixed
Two-Valve
5
Multi-Valve
6
Variable
Two-Valve
7
Multi-Valve
8
Gasoline Direct
Fixed
Multi-Valve
9
Injection (GDPI)
Variable
Multi-Valve
10
Gasoline Direct
Fixed
Multi-Valve
11
Injection (GDI)
Variable
Multi-Valve
12
Two-Valve
13
Diesel
14
BEV/FCEV
15
-------
Figure 4.7 shows the changes in specific power and fuel consumption per horsepower for
each of these engine packages over time. There is a very clear increase in specific power of
each engine package as engines moved from carbureted engines to engines with two
valves, fixed timing, and port fuel injection, then to engines with multi-valve VVT and port
fuel injection, and finally to GDI engines. Some of the increase for GDI engines may also be
due to the pairing of GDI engines with turbochargers to further increase power. Vehicles
with fixed valve timing and two valves per cylinder have been limited in recent years and
are no longer included in Figure 4.7 after model year 2015 due to very limited production.
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Figure 4.7. Engine Metrics for Different Gasoline Technology Packages
1.6
1.2
0.8
0.4
Variable Timing,
Multi-Valve Engines
Fixed Timing,
Two-Valve Engines
Carbureted Engines
a
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0.06-
0.05-
0.04-
0.03-
0.02-
Carburetec
Engines
Fixed Timing,
Two-Valve Engines
Variable Timing,
Multi-Valve Engines
GDI Engines
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
60
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Turbocharging
Turbochargers increase the power that an engine can produce by forcing more air, and
thus fuel, into the engine. An engine with a turbocharger can produce more power than an
identically sized engine that is naturally aspirated or does not have a turbocharger.
Turbochargers are powered using the pressure of the engine exhaust as it leaves the
engine. Superchargers operate the same way as turbochargers but are directly connected
to the engine for power, instead of using the engine exhaust. Alternate turbocharging and
supercharging methods, such as electric superchargers, are also beginning to emerge. A
limited number of new vehicles utilize both a turbocharger and supercharger in one engine
package. Most current gasoline turbocharged engines also use GDI and WT. This allows for
more efficient engine operation, helps increase the resistance to premature combustion
(engine knock), and reduces turbo lag (the amount of time it takes for a turbocharger to
engage).
Gasoline turbocharged engines have grown steadily in the marketplace, accounting for
more than 35% of all production in model year 2023, as shown in Figure 4.8. Many of these
engines are applying turbochargers to create "turbo downsized" engine packages that can
combine the improved fuel economy of smaller engines during normal operation but can
provide the power of a larger engine by engaging the turbocharger when necessary. As
evidence of this turbo downsizing, most gasoline turbocharged engines in model year 2023
are either 4-cylinder or 3-cylinder engines. Model year 2024 is projected to be a similar
distribution, as shown in Figure 4-9.
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Figure 4.8. Gasoline Turbo Engine Production Share by Vehicle Type
03
-C
CO
c
o
"O
o
40%-
30% -
20% -
10%-
0% -
Vehicle Type
Sedan/Wagon
¦ Car SUV
Truck SUV
Minivan/Van
| Pickup
2003
2008
2013
Model Year
2018
2023
Figure 4-9. Gasoline Turbo Engine Production Share by Number of Cylinders
40%-
30% -
(J)
o 20% -|
o
D
"D
O
Cylinders
3 Cylinder
4 Cylinder
I 6 Cylinder
8 Cylinder
I Other
10%-
0%-
0
a
¦¦¦¦niiiiiii
2003
2008
2013
Model Year
2018
2023
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Cylinder Deactivation
Cylinder deactivation is an engine management approach that turns off the flow of fuel to
one or more engine cylinders, and the corresponding spark plugs, when driving conditions
do not require full engine power. This effectively allows a large engine to act as a smaller
engine when the additional cylinders are not needed, increasing engine efficiency and fuel
economy. The use of cylinder deactivation in gasoline vehicles steadily climbed through
model year 2021, but fell slightly, less than one percentage point, in model year 2023 to
15% of all new vehicles. Projected model year 2023 data suggests another small drop in the
use of cylinder deactivation across all new vehicles.
Non-hybrid Stop/Start
Engine stop/start technology allows the engine to be automatically turned off at idle and
very quickly restarted when the driver releases the brake pedal. By turning the engine off, a
vehicle can eliminate the fuel use and C02 emissions that would have occurred if the
engine was left running. This report began tracking stop/start technology in model year
2012 at less than one percent. Since then, the use of stop/start has increased to more than
50% of all new gasoline non-hybrid vehicles in model year 2023. While non-hybrid
stop/start systems have been used in a wide range of applications, they are found more
often in larger vehicles and engines, as shown in Figure 4.10 and Figure 4.11.
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Figure 4.10. Gasoline Non-Hybrid Stop/Start Production Share by Vehicle Type
(D
03
CO
£=
O
-4"
o
=3
"O
o
50%
40%
30%
20%
10%
0%
Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
I Pickup
2010
^lallllll
2015
2020
2025
Model Year
Figure 4.11. Gasoline Non-Hybrid Stop/Start Production Share by Number of
Cylinders
50%
40%
Cylinders
4 Cylinder
| 6 Cylinder
8 Cylinder
Other
oj
CO
.c
(1.1
c
o
-4"
O
=3
"O
O
30%
20%
10%
0%
2010
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2015
2020
2025
Model Year
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Hybrids
Gasoline hybrid vehicles feature a battery pack that is larger than the battery found on a
typical gasoline vehicle, which allows these vehicles to store and strategically apply
electrical energy to supplement the gasoline engine. The result is that the engine can be
smaller than what would be needed in a non-hybrid vehicle, and the engine can be
operated near its peak efficiency more often. Hybrids also frequently utilize regenerative
braking, which uses a motor/generator to capture energy from braking instead of losing
that energy to friction and heat, as in traditional friction braking, and stop/start technology
to turn off the engine at idle. The combination of these strategies can result in significant
reductions in fuel use and CO2 emissions.
The hybrid category includes "mild" hybrids (MHEVs), which employ a lower voltage
electrical system that can provide launch assist and assist the engine but cannot directly
propel the vehicle. "Strong" hybrid systems (HEVs) can temporarily power the vehicle
without engaging the engine and may be able to capture more regenerative braking. For
the purposes of this report, new vehicles with a 48V or less electrical system are classified
as mild hybrids, while higher voltage electrical systems are classified as strong hybrids.
Hybrids were first introduced in the U.S. marketplace in model year 2000 with the Honda
Insight. As more models and options were introduced into the market, hybrid production
increased to 3.8% of all vehicles in model year 2010, before slowly declining to 1.8% of new
vehicle production in model year 2016. Since model year 2016 however, the percent of new
vehicles that are hybrids has steadily grown and reached a new high of 12.1 % of all new
vehicles in model year 2023. Hybrid growth is projected to continue growing in model year
2024, to 14.6% of new vehicle production.
Early hybrids were mostly the sedan/wagon vehicle type, but recent growth in other vehicle
types, particularly truck SUVs, has propelled recent growth, as shown in Figure 4.12. In
model year 2020, the production of hybrids in the truck SUV category surpassed the
production of sedan/wagon hybrids for the first time and did so by more than 50%. Hybrids
are also being used in the pickup and minivan/van vehicle types. Sedan/wagon hybrids
accounted for only 25% of all hybrid production in model year 2023. Hybrid vehicles
typically use a 4-cylinder engine, although an increasing number of 6- and 8-cylinder
engines are being used in hybrid systems, as shown in Figure 4.13.
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Figure 4.12. Gasoline Hybrid Engine Production Share by Vehicle Type
15%-
Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
| Pickup
10%-
5% -
0%-
II
2000
2005
2010 2015
Model Year
2020
2025
Figure 4.13. Gasoline Hybrid Engine Production Share by Number of Cylinders
15%
10%
a
a
u
5% ¦
0%
Cylinders
4 Cylinder
| 6 Cylinder
8 Cylinder
I Other
2000 2005 2010 2015 2020 2025
Model Year
66
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While strong hybrids have grown market penetration in recent years, the growth of mild
hybrids from very limited numbers to current production has contributed to the overall
market share rise for hybrids. Mild hybrids accounted for about 40% of hybrid production
in model year 2023, as shown in Figure 4.14.
Figure 4.14. Gasoline Hybrid Engine Production Share Hybrid Type
15%
Hybrid Type
MHEV
I HEV
g>
TO
-C
CO
c
o
¦-4'
o
3
T3
O
10%
5% ¦
0%-
2000
2005
2010
2015
2020
2025
Model Year
Plug-In Hybrid Electric, Battery Electric, and Fuel Cell Electric
Vehicles
PHEVs and BEVs are two types of vehicles that can store electricity from an external source
onboard the vehicle, utilizing that stored energy to propel the vehicle. PHEVs are similar to
gasoline hybrids discussed previously, but the battery packs in PHEVs can be charged from
an external electricity source; this cannot be done in mild or strong hybrids. BEVs operate
using only energy stored in a battery from external charging. Fuel cell electric vehicles use a
fuel cell stack to create electricity from an onboard fuel source (usually hydrogen), which
then powers an electric motor or motors to propel the vehicle. The use of electricity instead
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of gasoline as a fuel source complicates the comparison of BEVs (and PHEVs) to ICE
vehicles, requiring different metrics11 and an evolving analysis of vehicle technology.
BEVs rely on electricity stored in a battery for fuel. Combustion does not occur onboard the
vehicle, and therefore there are no tailpipe emissions created by the vehicle. The electricity
used to charge BEVs can create emissions at the power plant. The amount of emission
varies depending on the fuel source of the electricity, which can in turn vary based on
location and time of day. The electric grid in the U.S. has also been changing over time, as
natural gas and renewable energy resources make up a growing portion of electricity
generation across the U.S. Depending on the source of electricity, BEVs often result in
lower CO2 emissions over their lifetime compared to gasoline vehicles.
Since BEVs do not use gasoline, the familiar metric of miles per gallon cannot be applied to
BEVs. Instead, BEVs are rated in terms of miles per gallon-equivalent (mpge), which is the
number of miles that a BEV travels on an amount of electrical energy equivalent to the
energy in a gallon of gasoline. This metric enables a direct comparison of energy efficiency
between BEVs and gasoline vehicles. BEVs generally have a much higher energy efficiency
than gasoline vehicles because electric motors are much more efficient than gasoline
engines.
PHEVs can operate either on electricity stored in a battery, or gasoline, allowing for a wide
range of engine designs and strategies for the utilization of stored electrical energy during
typical driving. Most PHEVs will operate on electricity only, like a BEV, for a limited range,
and then will operate like a strong hybrid until their battery is recharged from an external
source. The use of electricity to provide some or all of the energy required for propulsion
can significantly lower fuel consumption and tailpipe CO2 emissions. For a much more
detailed discussion of BEV and PHEV metrics, as well as upstream emissions from
electricity, see Appendix E.
The production of BEVs and PHEVs has increased rapidly in recent years. Prior to model
year 2011, BEVs were available, but generally only in small numbers for lease in
California.12 In model year 2011 the first PHEV, the Chevrolet Volt, was introduced along
with the Nissan Leaf BEV. Many additional models have been introduced since, and in
model year 2023 combined BEV/PHEV production reached almost 12% of all new vehicles.
Combined BEV and PHEV production is projected to reach a new high of almost 15% of all
production in model year 2024. In model year 2023 there were two hydrogen FCEV models
11 See Appendix E for a detailed discussion of BEV and PHEV metrics.
12 At least over the timeframe covered by this report. BEVs were initially produced more than 100 years ago.
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produced, but they were only available in small numbers and in the state of California and
Hawaii. However there continues to be interest in FCEVs as a future technology. The trend
in EVs, PHEVs, and FCEVs are shown in Figure 4.15.
Figure 4.15. Production Share of BEVs, PHEVs, and FCEVs13
15%
£ 10%
CO
5%
0%
Plug-In Hybrid Electric Vehicle
Battery Electric Vehicle
Fuel Cell Electric Vehicle
.¦¦II
1995 2000 2005 2010
Model Year
2015
2020
2025
The inclusion of model year 2023 BEV and PHEV production reduced the overall new
vehicle average CO2 emissions by 38 g/mi and increased new vehicle average fuel economy
by 2.2 mpg, as shown in Figure 4.16. Without BEV and PHEV production, the CO2 emissions
and fuel economy of the remaining new vehicles was relatively flat.
13 BEV production data were supplemented with data from Ward's and other publicly available production data
for model years prior to 2011. The data only include offerings from original equipment manufacturers and does
not include data on vehicles converted to alternative fuels in the aftermarket.
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Figure 4.16. Impact of BEVs and PHEVs
400
375
350
325
300
t t
Without BEVs and PHEVs: 357
*
I
All New Vehicles: 319
28-
26
? 24-
22
All New Vehicles: 27.1
9 - - |
8 § Without BEVs and PHEVs: 24.9
2010
2015 2020
Model Year
2025
Figure 4.17 and Figure 4.18 show the production share by vehicle type for BEVs and PHEVs.
Early production of BEVs was mostly in the sedan/wagon vehicle type, but recent model
years have shown growth in car SUVs and truck SUVs. Electric pickup trucks first entered
the market in model year 2022, along with new BEV models across many of the vehicle
types. Production of PHEVs has shifted from exclusively sedan/wagons to mostly truck
SUVs, with limited production across the sedan/wagon, car SUV, and minivan/van vehicle
types.
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Figure 4.17. Battery Electric Vehicle Production Share by Vehicle Type
12%-
9%-
6%-
3%-
0%-
VehicleType
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
I Pickup
2010
2015
2020
2025
Model Year
Figure 4.18. Plug-In Hybrid Vehicle Production Share by Vehicle Type
E
TO
.C
CO
c
o
3
T3
O
12%
9%-
6%-
3%-
0%-
Vehicle Type
Sedan/Wagon
| Car SUV
Truck SUV
Minivan/Van
2010
2015
2020
2025
Model Year
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Figure 4.19 shows the range and fuel economy trends for BEVs and PHEVs14. The average
range of new BEVs has climbed substantially. In model year 2023, the average new BEV
range is 292 miles, or almost four times the range of an average BEV in 2011. The range
values shown for PHEVs are the charge-depleting range, where the vehicle is operating on
energy in the battery from an external source. This is generally the all-electric range of the
PHEV, although some vehicles also use the gasoline engine in small amounts during charge
depleting operation. The average charge depleting range for PHEVs has remained largely
unchanged since model year 2011.
Figure 4.19. Charge Depleting Range and Fuel Economy for BEVs and PHEVs
Range (mi) Fuel Economy (mpge)
Model Year Model Year
The fuel economy of electric vehicles has also improved since model year 2011, as
measured in miles per gallon of gasoline equivalent (mpge). In model year 2022 and 2023
14 The range and fuel economy values in this figure are the combined values from the fuel economy label, which
weights city and highway driving 55% and 45%, as compared to the rest of the report, which uses a 43% city and
57% highway weighting. See Appendix C for more information.
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the fuel economy of average new BEVs fell, mostly due to the introduction of larger vehicles
that have lower overall fuel economy ratings. The combined fuel economy of PHEVs has
been more variable but is about 35% lower in model year 2023 than in model year 2011
and is expected to decrease further in 2024. This may be attributable to the growth of truck
SUV PHEVs, as shown in Figure 4.18. For more information about BEV and PHEV metrics,
see Appendix E.
As the number of electric vehicles available continues to increase and diversify, comparing
technology trends across electric vehicles will become more meaningful and important.
Figure 4.20 shows the distribution of BEV energy consumption, in terms of kWh per 100
miles, compared to vehicle inertia weight class. There is a general trend that heavier EVs
have a higher energy consumption, but there is a large spread at each inertia weight class.
Pickups and truck SUVs represent the heaviest BEVs and are somewhat less efficient than
other vehicle types, consistent with trends across the broader industry.
Figure 4.20. BEV Energy Consumption by Weight and Vehicle Type
60-
VehicleType
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
Pickup
3500 4000 4500 5000 5500 6000 6500 7000 7500
Inertia Weight (lbs)
ID
a J 73
5 0 ' °
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Diesel Engines
Vehicles with diesel engines have been available in the U.S. at least as long as EPA has been
collecting data. However, sales of diesel vehicles have rarely broken more than 1 % of the
overall market. Diesel vehicle sales peaked at 5.9% of the market in model year 1981 but
have been at or below 1 % of production per year since 1985. In MY 2023, diesel vehicles
were slightly below 1% of all new vehicles produced.
Vehicles that rely on diesel fuel often achieve higher fuel economy than gasoline vehicles,
largely because the energy density of diesel fuel is about 15% higher than that of gasoline.
However, there is less of an advantage in terms of CO2 emissions because diesel fuel also
contains about 15% more carbon per gallon, and thus emits more CO2 per gallon burned
than gasoline.
Figure 4.21 shows the production share of diesel engines by vehicle type. Diesel engines
have historically been more prevalent in the sedan/wagon vehicle type, however, since
model year 2015 there have been very few sedan/wagon vehicles with diesel engines and
most light-duty diesel production has been pickups. This report does not include the
largest heavy-duty pickup trucks, work vans, or vocational trucks, which have a higher
penetration of diesel engines. As shown in Figure 4.22, current production of diesel engines
for light-duty vehicles is largely comprised of six-cylinder engines, along with a smaller
share of 4-cylinder engines.
Diesel engines, as with gasoline engines, have improved over time. Figure 4.23 shows the
same metrics and trends that are explored in Figure 4.5 for gasoline engines. The specific
power (HP/displacement) for diesel engines has increased more than 200% since model
year 1975. Fuel consumption per displacement dropped in the 1980s but has increased
back to about 20% below model year 1975. Finally, fuel consumption per horsepower for
diesel engines has declined about 75% since model year 1975.
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Figure 4.21. Diesel Engine Production Share by Vehicle Type
6%
<1)
&_
05
-C
CD
c
o
o
~C5
o
4% -
Q_ 2%
0%
Vehicle Type
Sedan/Wagon
| Car SUV
Truck SUV
Minivan/Van
| Pickup
llli
i 1 1 1 1 1 1 1 1 1
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Figure 4.22. Diesel Engine Production Share by Number of Cylinders
Cylinders
4 Cylinder
16 Cylinder
8 Cylinder
1 Other
..1
1,..
...illll
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
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Figure 4.23. Percent Change for Specific Diesel Engine Metrics
250%
200%
150%
0
o
(§ 100%
0
cn
c
CO
O
50%
0%
-50%
HP/Displacement i
Fuel
Consumption/Displacement
Fue
Consumption/HP
¦
1975 1980 1985
1990 1995 2000 2005
Model Year
2010 2015 2020 2025
Other Engine Technologies
In addition to the engine technologies described above, there have been a small number of
other technologies available in the U.S. marketplace over the years. Vehicles that operate
on compressed natural gas (CNG) are one example, but there are currently no CNG
vehicles available from vehicle manufacturers (aftermarket conversions are not included
here). This report will continue to track all vehicles produced for sale in the U.S., and if CNG
or other technologies reach widespread availability they will be included in future versions
of this report.
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B. Vehicle Drivetrain
A vehicle drivetrain includes all components responsible for transmitting rotational energy
from an engine or electric motor to the wheels. The design of the drivetrain impacts CO2
emissions and fuel economy in two ways; first through direct energy losses or inefficiencies
within the drivetrain, and second by allowing a vehicle's engine, or electric motor, to
operate in a more efficient manner.
For non-hybrid vehicles with an internal combustion engine, the drivetrain includes a
transmission and the driveline (a driveshaft, differential, axle shafts and related
components), as shown in Figure 4.24. Mild hybrids generally use a conventional
transmission and drivetrain, but strong hybrids often replace the transmission entirely with
a planetary gearset or some other enabling configuration. PHEVs generally resemble full
hybrids but can have numerous configurations that allow for complicated energy
optimization. Battery electric vehicles generally use a single speed transmission and do not
need the numerous gears required by combustion engines. However, some high-
performance electric vehicles are now being produced with 2-speed transmissions (e.g.,
Porsche Taycan).
Transmissions
There are two important aspects of transmissions that impact overall vehicle efficiency and
fuel economy. First, as torque (rotational force) is transferred through the transmission, a
small amount is lost to friction, which reduces vehicle efficiency. Second, the design of the
transmission impacts how the engine is operated, and generally transmissions with more
speeds offer more opportunity to operate the engine in the most efficient way possible. For
example, a vehicle with an eight-speed transmission will have more flexibility in
determining engine operation than a vehicle with a five-speed transmission. This can lead
to reduced fuel consumption and CO2 emissions compared to a vehicle that is identical
except for the number of transmission gears.
Transmission designs have been rapidly evolving to increase the number of gears available
and allow for both better engine operation and improved efficiency. The number of gears
in new vehicles continues to increase, as does the use of continuously variable
transmissions (CVTs). Figure 4.24 shows the evolution of transmission production share for
cars and trucks since model year 1980.15 For this analysis, transmissions are separated into
15 EPA has incomplete transmission data prior to model year 1980.
S T 77
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manual transmissions, CVTs, and automatic transmissions. Automatic transmissions are
further separated into those with and without lockup mechanisms, which can lock up the
torque converter in an automatic transmission under certain driving conditions and
improve efficiency. CVTs have also been split into hybrid and non-hybrid versions to reflect
the fact that hybrid CVTs are generally very different mechanically from traditional CVTs.
The hybrid CVT category includes CVTs used for PHEVs.
Dual clutch transmissions (DCTs) are essentially automatic transmissions that operate
internally much more like traditional manual transmissions. The two main advantages of
DCTs are that they can shift very quickly, and they can avoid some of the internal resistance
of a traditional automatic transmission by eliminating the torque converter. Currently,
automaker submissions to EPA do not explicitly identify DCTs as a separate transmission
category. Thus, the introduction of DCTs shows up in Figure 4.24 as a slight increase in
automatic transmissions without torque converters (although some DCTs may still be
reported as traditional automatic transmissions).
In the early 1980s, three-speed automatic transmissions, both with and without lockup
torque converters (shown as L3 and A3), were the most popular transmissions, but by
model year 1985, the four-speed automatic transmission with lockup (L4) became the most
popular transmission, a position it would hold for 25 years. Over 80% of all new vehicles
produced in model year 1999 were equipped with a four-speed transmission. After model
year 1999, the production share of four-speed transmissions slowly decreased as five and
six speed transmissions were introduced into the market. Six-speed transmissions peaked
in model year 2013 at 60% of new vehicle production, but then fell quickly, down to 8% by
model year 2023. Eight-speed transmissions became the most popular transmission in
model year 2019. In model year 2023, vehicles with eight-speed transmissions accounted
for about 30% of all new vehicles, while vehicles with CVTs or vehicles with transmissions of
nine or more speeds each accounted for more than 20% of new vehicle production.
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Figure 4.24. Transmission Production Share
100%-
CD
CD
-C
CD
c
o
'¦4'
o
"O
o
75% -
50% -
25% -
0%-
100%^
75% -
50% -
25%
0%-
L4
L3
A4^
A3
03
o
M6^
M5
^ 110
M4
L9
M3
L4
L5 L6
L8
L3
A3
CVT(H)
CVT(N-H)^ A8yJ_A6
o
1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Transmission
Lockup?
Number of Gears
Key
Single Speed
-
1
SS
Automatic
No
2
A2*
Semi-Auto matic
3
A3
Automated Manual
4
A4
5
A5*
6
A6
7
A7
8
A8
Yes
2
L2*
3
L3
4
L4
5
L5
6
L6
7
L7
8
ls
9
L9
10
L10
Manual
-
3
M3
4
M4
5
M5
6
M6
7
M7*
Continuously\teriable
(Non-Hybrid)
CVT(N-H)
Continuously\teriable
(Hybrid)
CVT(H)
Other
-
OT
'Categories A2, A5, L2, and M7 are too small to depict in the area plot.
79
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Transmission trends also vary by vehicle engine technology, as shown in Figure 4.25. For
model year 2023, diesel engines were most often paired with a ten-speed lockup
transmission, with some eight speed transmissions. Gasoline engines were paired with a
wide variety of transmissions, including CVTs, lockup transmissions from ten to five speeds,
a small number of manual transmissions, and a small number of non-lockup transmissions
(likely dual clutch transmissions). Mild hybrids are most often paired with an eight or nine
speed transmission, while strong hybrids most often use a hybrid CVT transmission. PHEVs
currently use a wide array of transmission technologies, including traditional automatic
transmissions, CVTs, and single-speed transmissions. BEVs are generally designed without
a traditional transmission and utilize a single speed design. However, a limited number of
high-performance EVs do have a 2-speed transmission.
Figure 4.25. Transmission By Engine Technology, Model Year 2023
100%-
75% -
CD
CO
-C
(/)
c
o
'¦4'
o
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o
50% -
25% -
Diesel
Gasoline
ICE
MHEV HEV
Fuel Type
PHEV
BEV
Transmission
¦
Single Speed
A2
A6
A7
¦
A8
CVT (Hybrid)
CVT (Non-Hybrid)
L5
L6
L7
L8
L9
¦
L10
M5
M6
¦
M7
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Another notable trend in Figure 4.24 is the decline in manual transmissions. Manual
transmissions were included in almost 35% of new vehicles in model year 1980, but have
been gradually declining since, and have been below 1 % of all production since model year
2021. Today, manual transmissions are available only in a limited number of small vehicles,
sports cars, off-road truck SUVs, and a few small pickups.
Part of the reason for the decline in manual transmission is because modern automatic
transmissions are now generally more efficient and can offer better performance than
manual transmissions. In the past, automatic transmissions have generally been less
efficient than manual transmissions, largely due to inefficiencies in the automatic
transmission torque converter and fewer gears. Over time, both manual and automatic
transmissions added gears, but automatic transmissions added gears faster. In model year
2012, the average number of gears in an automatic transmission passed the average
number of gears in a manual transmission. Figure 4.26 shows the average number of gears
in new vehicle transmissions since model year 1980 for automatic and manual
transmissions (excluding BEVs and PHEVs). The continued shrinking availability of manual
transmissions in each model year limits the relevance of analyses comparing current
manual transmissions to automatic transmissions.
Figure 4.26. Average Number of Transmission Gears
03
CD
o
CD
-Q
E
CD
O)
CD
CD
<:
a
a
~
u
8
5-
4-
3-
/
^
Manual
fAutomatic
1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
81
-------
Drive Types
There has been a long and steady trend in new vehicle drive type away from rear-wheel
drive vehicles towards front-wheel drive and four-wheel drive (including all-wheel drive)
vehicles, as shown in Figure 4.27. In model year 1975, over 91 % of new vehicles were
produced with rear-wheel drive. Since then, production of rear-wheel drive vehicles has
steadily declined to about 10% in model year 2023. Most vehicles available today with rear
wheel drive are performance-oriented sedan/wagons and pickup trucks, but there are
limited rear wheel drive vehicles available in all vehicle types.
Production of front-wheel drive vehicles increased from 5% of new vehicle production in
model year 1975 to 64% in model year 1990 and 63% in model year 2009. Since 2009
however, the production of front-wheel vehicles has also been declining and is down to
29% in model year 2023. Four-wheel drive systems have steadily increased from 3.3% of
new vehicle production in model year 1975 to 61 % of production in model year 2023. Four-
wheel drive systems have increased for both cars and trucks, but the high penetration rate
of 83.0% within trucks (including pickups, truck SUVs, and minivan/vans) and the market
shifts towards these vehicles has accelerated the trend towards four-wheel drive vehicles.
Figure 4.27. Front-, Rear-, and Four-Wheel Drive Production Share
<1)
&_
05
-C
CD
c
o
o
~C5
o
0
a
100%-
u
75% ¦
50%-
25% ¦
0%-
Drive
Four-Wheel
Front-Wheel
Rear-Wheel
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
82
-------
C. Technology Adoption and Comparison
One additional way to evaluate the evolution of technology in the automotive industry is to
focus on how technology has been adopted over time. Understanding how the industry has
adopted technology can lead to a better understanding of past changes in the industry,
and how emerging technology may be integrated in the future. The following analysis
provides more details about how manufacturers and the overall industry have adopted
new technology.
Industry-Wide Technology Adoption Since 1975
Figure 4.28 shows industry-wide adoption rates for seven technologies in passenger cars.
These technologies are fuel injection (including throttle body, port, and direct injection),
front-wheel drive, multi-valve engines (i.e., engines with more than two valves per cylinder),
engines with variable valve timing, lockup transmissions, advanced transmissions
(transmissions with six or more speeds, and CVTs), and gasoline direct injection engines. To
provide a common scale, the adoption rates are plotted in terms of the number of years
after the technology achieved first significant use in the industry. First significant use
generally represents a production threshold of 1 %, though in some cases, where full data
are not available, first significant use represents a slightly higher production share.
The technology adoption pattern shown in Figure 4.28 is roughly similar for each of the
seven technologies, even though they vary widely in application, complexity, and when they
were initially introduced. It has taken, on average, approximately 15-20 years for new
technologies to reach maximum penetration across the industry. GDI is a newer technology
that has likely not reached maximum penetration across the industry but appears to be
following the adoption trend of other more mature technologies. While some of these
technologies may eventually be adopted in 100% of new vehicles, there may be reasons
that other technologies, like front-wheel drive, will likely never be adopted in all vehicles.
Adoption rates for these technologies in trucks are similar, with the exception of front-
wheel drive.
The analysis for Figure 4.28 focuses on technologies that have achieved widespread use by
multiple manufacturers and does not look at narrowly adopted technologies which never
achieved widespread use. One limitation to the data in this report is that EPA does not
begin tracking technology production share data until after the technologies had achieved
some limited market share. For example, EPA did not begin to track multi-valve engine data
until model year 1986 for cars and model year 1994 for trucks, and in both cases multi-
83
u
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valve engines had captured about 5% market share by that time. Likewise, turbochargers
were not tracked in this report until model year 1996 for cars and model year 2003 for
trucks, and while turbochargers had less than a 1 % market share in both cases at that time,
it is likely that turbochargers had exceeded 1 % market share in the late 1980s. Cylinder
deactivation was utilized by at least one major manufacturer in the 1980s.
Figure 4.28. Industry-Wide Car Technology Penetration after First Significant
Use
CD
03
O
-4"
o
"O
o
100%-
80% -
w 60% -
40% -
20% -
0% -
Fuel Injection
Advanced /V
Transmission / / ^ ^
Lockup
/iVIulti-Valvi
a \
Front-Wheel \
/ LGD\^y
Drive
' J Variable-Valve
/ Timing
10 20 30 40
Years after First Significant Use
50
Technology Adoption by Manufacturers
The rate at which the overall industry adopts technology is determined by how quickly, and
at what point in time, individual manufacturers adopt the technology. While it is important
to understand the industry-wide adoption rates over time, the trends in Figure 4.28 mask
the fact that not all manufacturers introduced these technologies at the same time, or at
the same rate. The "sequencing" of manufacturers introducing new technologies is an
important aspect of understanding the overall industry trend of technology adoption.
Figure 4.29 begins to disaggregate the industry-wide trends to examine how individual
manufacturers have adopted new technologies.16 For each technology, Figure 4.29 shows
16 This figure is based on available data. Some technologies may have been introduced into the market before
this report began tracking them. Generally, these omissions are limited, with the exception of multi-valve
engine data for Honda. Honda had already achieved 70% penetration of multi-valve engines when this report
began tracking them in 1986, so this figure does not illustrate Honda's prior trends.
0
a
~
u
84
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the amount of time it took specific manufacturers to move from initial introduction to 80%
penetration for each technology, as well as the same data for the overall industry. After
80% penetration, the technology is assumed to be largely incorporated into the
manufacturer's fleet, and changes between 80% and 100% are not highlighted.
Of the seven technologies shown in Figure 4.29, five are now at or near full market
penetration for the included manufacturers, and two are still in the process of adoption by
manufacturers. The technologies shown in Figure 4.29 vary widely in terms of complexity,
application, and when they were introduced into the market. For each technology, there
are clearly variations between manufacturers, both in terms of when they began to adopt a
technology, and the rate with which they adopted the technology. The degree of variation
between the manufacturers also varies by technology.
The data for WT, for example, show that several manufacturers adopted the technology
much faster than the overall industry, which achieved 80% penetration in just over 20
years. It was not the rate of technology adoption alone, but rather the staggered
implementation timeframes among manufacturers that resulted in the longer industry-
wide average.
Fuel injection systems show the least amount of variation in initial adoption timing
between manufacturers, which resulted in a faster adoption by the industry overall than
technologies like WT. One important driver for adoption of fuel injection was increasingly
stringent emissions standards. Advanced transmissions, which have been available in small
numbers for some time, have very rapidly increased market penetration in recent years
and are now widely adopted. GDI engines appear to be following a similar path of quick
uptake in recent years. Turbocharged engines have long been available, but the focus on
turbo downsized engine packages is leading to much higher market penetration, although
it is too early to tell what level of penetration, they will ultimately achieve industry wide.
There are many factors outside the scope of this report that influence the rate and timing
of when technology is adopted by individual manufacturers (e.g., price, manufacturing
constraints, regulatory drivers, etc.) While no attempt is made here to identify the
underlying causes, it is important to recognize that variation between manufacturers for
given technologies can be masked when only the industry-wide trends are evaluated.
Technology adoption by individual manufacturers is often more rapid than the overall
industry trend would suggest.
~
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Sk
85
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Figure 4.29. Manufacturer Specific Technology Adoption over Time for Key
Technologies
<1)
i
O
a
c
05
Toyota ¦
GM ¦
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai1
AH Manufacturers1
Toyota ¦
GM ¦
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai1
AH Manufacturers1
Toyota.
GM.
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai ¦
AH Manufacturers¦
Toyota.
GM.
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai ¦
AH Manufacturers¦
Toyota.
GM.
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai ¦
AH Manufacturers¦
Toyota
GM.
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai ¦
AH Manufacturers¦
Toyota.
GM.
Ford ¦
Stellantis ¦
Honda¦
Nissan ¦
Hyundai ¦
AH Manufacturers¦
Fuel Injection
1975 1980
1990
2000
2010
2020 2025
Lockup
1975 1980
1990
2000
2010
2020 2025
Multi-Valve
1975 1980
1990
2000
2010
2020 2025
1975 1980
Variable Valve
Timing
1990
2000
2010
2020 2025
Advanced
Transmissions
1975 1980
1990
2000
2010
2020 2025
1975 1980
Gasoline Direct
Injection
1990
2000
2010
2020 2025
1975 1980
Turbocharged
1990 2000
Model Year
2010
2020 2025
Percent of Production
20% to 25%
10% to 15%
0% to 5% I
I I
25% to 50% 75% to 80%
I 15% to 20% 50% to 75%
80% to 100%
5% to 10%
a
a
~
u
86
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Table 4.2. Production Share by Powertrain
Model Year
Diesel ICE
Gasoline
ICE without
Stop/Start
Gasoline
ICE with
Stop/Start
Mild
Hybrid
(MHEV)
Strong
Hybrid
(HEV)
Plug-in
Hybrid
(PHEV)
Battery
Electric
(BEV)
Fuel Cell
Electric
(FCEV)
Other
1975
0.2%
99.8%
-
-
-
-
-
-
-
1980
4.3%
95.7%
-
-
-
-
-
-
-
1985
0.9%
99.1%
-
-
-
-
-
-
-
1990
0.1%
99.9%
-
-
-
-
-
-
-
1995
0.0%
100.0%
-
-
-
-
-
-
-
2000
0.1%
99.8%
-
0.0%
-
-
-
-
-
2005
0.3%
98.6%
-
0.3%
0.8%
-
-
-
-
2010
0.7%
95.5%
-
0.0%
3.8%
-
-
0.0%
-
2011
0.8%
97.0%
-
-
2.2%
0.0%
0.1%
0.0%
0.0%
2012
0.9%
95.2%
0.3%
0.1%
3.0%
0.3%
0.1%
0.0%
0.0%
2013
0.9%
92.6%
2.3%
0.3%
3.3%
0.4%
0.3%
-
0.0%
2014
1.0%
90.8%
4.9%
0.1%
2.5%
0.4%
0.3%
0.0%
0.0%
2015
0.9%
88.9%
7.0%
0.0%
2.4%
0.3%
0.5%
0.0%
0.0%
2016
0.5%
87.5%
9.4%
0.0%
1.8%
0.3%
0.5%
0.0%
0.0%
2017
0.3%
78.4%
17.7%
0.0%
2.3%
0.8%
0.6%
0.0%
-
2018
0.4%
65.5%
29.6%
0.4%
1.9%
0.8%
1.4%
0.0%
-
2019
0.1%
57.6%
36.8%
1.3%
2.5%
0.5%
1.2%
0.0%
-
2020
0.5%
46.9%
45.4%
1.8%
3.1%
0.5%
1.8%
0.0%
-
2021
1.0%
41.1%
44.0%
4.0%
5.3%
1.2%
3.2%
0.0%
-
2022
0.8%
33.4%
48.9%
4.2%
6.0%
1.5%
5.2%
0.0%
-
2023
0.8%
26.3%
49.2%
4.9%
7.2%
1.7%
9.8%
0.0%
-
2024 (prelim)
0.8%
14.9%
55.0%
5.3%
9.3%
3.3%
11.4%
0.1%
-
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
~
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Table 4.3. Production Share by Fuel Delivery Method
Model
Year
Gasoline Engines -
Fuel Delivery Method
Carb TBI
Port
GDI
GDPI
1975
95.7% 0.0%
4.1%
-
-
1980
89.7% 0.8%
5.2%
-
-
1985
56.1% 24.8%
18.2%
-
-
1990
2.1% 27.0%
70.8%
-
-
1995
8.4%
91.6%
-
-
2000
0.0%
99.8%
-
-
2005
-
99.7%
-
-
2010
-
91.0%
8.3%
-
2011
-
83.8%
15.4%
-
2012
-
76.4%
22.5%
0.1%
2013
-
67.7%
30.5%
0.6%
2014
-
60.9%
37.4%
0.4%
2015
-
56.0%
41.9%
0.7%
2016
-
48.7%
48.0%
2.3%
2017
-
44.2%
49.7%
5.2%
2018
-
37.7%
50.2%
10.3%
2019
-
31.6%
52.9%
14.2%
2020
-
26.6%
57.1%
14.0%
2021
-
23.6%
53.4%
18.7%
2022
-
21.0%
52.3%
20.6%
2023
-
16.0%
50.5%
22.9%
2024
(prelim)
-
11.8%
54.6%
21.4%
Ok
~
u
Diesel
BEV
Other
0.2%
-
-
4.3%
-
-
0.9%
-
-
0.1%
-
-
0.0%
-
-
0.1%
-
-
0.3%
-
-
0.7%
-
0.0%
0.8%
0.1%
0.0%
0.9%
0.1%
0.0%
0.9%
0.3%
-
1.0%
0.3%
0.0%
0.9%
0.5%
0.0%
0.5%
0.5%
0.0%
0.3%
0.6%
0.0%
0.4%
1.4%
0.0%
0.1%
1.2%
0.0%
0.5%
1.8%
0.0%
1.0%
3.2%
0.0%
0.8%
5.2%
0.0%
0.8%
9.8%
0.0%
0.8%
11.4%
0.1%
88
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Table 4.4. Production Share by Gasoline17 Engine Technologies
Variable Valve
Cylinder
Non-hybrid
Avg. No. of
Displacement
Horsepower
Multi-
Timing
Deactivation
Turbo-
Stop/
Model Year
Cylinders
(CID)
(HP)
Valve
(VVT)
(CD
charged
Start
1975
6.8
293
137
-
-
^1
-
-
1980
5.6
196
105
-
-
-
-
-
1985
5.5
189
114
-
-
-
-
-
1990
5.4
185
135
23.1%
-
-
-
-
1995
5.6
196
158
35.5%
-
-
-
-
2000
5.7
200
181
44.8%
15.0%
-
1.2%
-
2005
5.8
205
209
65.5%
45.7%
0.8%
1.4%
-
2010
5.3
188
214
84.8%
83.8%
6.4%
2.6%
-
2011
5.4
193
230
85.6%
93.0%
9.5%
6.1%
-
2012
5.1
181
222
90.9%
96.5%
8.1%
7.5%
0.6%
2013
5.1
177
227
91.9%
97.4%
7.7%
13.0%
2.3%
2014
5.1
181
231
88.2%
97.6%
10.6%
13.8%
4.9%
2015
5.0
177
229
90.2%
97.2%
10.5%
14.8%
7.0%
2016
5.0
173
230
91.8%
98.0%
10.4%
19.4%
9.4%
2017
5.0
173
233
91.7%
98.1%
11.9%
23.2%
17.7%
2018
5.0
172
239
90.6%
96.4%
12.5%
29.6%
29.6%
2019
5.1
174
244
89.9%
97.2%
14.9%
29.8%
36.8%
2020
4.9
169
243
90.2%
95.8%
14.7%
34.2%
45.4%
2021
5.0
176
249
86.9%
94.4%
16.6%
31.8%
44.0%
2022
4.9
171
249
86.7%
92.5%
15.9%
35.8%
48.9%
2023
4.9
170
253
83.0%
88.0%
15.1%
37.3%
49.2%
2024 (prelim)
4.7
158
249
83.2%
87.5%
13.3%
44.4%
55.0%
17 This table includes technology penetration rates for new vehicles with gasoline engines, including hybrids and PHEVs (except for non-hybrid stop/start,
which excludes hybrids and PHEVs), as compared to all new vehicles. The values in this table are slightly lower than values elsewhere this report that
include other technologies. For example, most vehicles that operate on diesel fuel are turbocharged, and when included, as in Table 4.1, will slightly
increase the overall share of vehicles that are turbocharged.
89
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Table 4.5. Production Share by Transmission Technologies
Model Year
Manual
Automatic
with
Lockup
Automatic
without
Lockup
CVT
(Hybrid)
CVT
(Non-
Hybrid)
Other
4 Gears
or
Fewer
5
Gears
6
Gears
7
Gears
8
Gears
9+
Gears
Average
No. of
Gears
1975
23.0%
0.2%
76.8%
-
-
^1
99.0%
1.0%
-
-
-
-
-
1980
34.6%
18.1%
46.8%
-
-
0.5%
87.9%
12.1%
-
-
-
-
3.5
1985
26.5%
54.5%
19.1%
-
-
-
80.7%
19.3%
-
-
-
-
3.7
1990
22.2%
71.2%
6.5%
-
0.0%
0.0%
79.9%
20.0%
0.1%
-
-
-
4.0
1995
17.9%
80.7%
1.4%
-
-
-
82.0%
17.7%
0.2%
-
-
-
4.1
2000
9.7%
89.5%
0.7%
-
0.0%
-
83.7%
15.8%
0.5%
-
-
-
4.1
2005
6.2%
91.5%
0.1%
1.0%
1.3%
-
56.0%
37.3%
4.1%
0.2%
-
-
4.5
2010
3.8%
84.1%
1.2%
3.8%
7.2%
-
24.6%
23.5%
38.1%
2.7%
0.2%
-
5.2
2011
3.2%
86.5%
0.3%
2.0%
8.0%
-
14.2%
18.7%
52.3%
3.1%
1.7%
-
5.5
2012
3.6%
83.4%
1.1%
2.9%
8.9%
-
8.1%
18.2%
56.3%
2.8%
2.6%
-
5.5
2013
3.5%
80.4%
1.4%
3.3%
11.4%
-
5.4%
12.8%
60.1%
2.8%
4.1%
-
5.6
2014
2.8%
76.7%
1.6%
2.7%
16.3%
-
2.2%
7.8%
58.4%
3.3%
8.4%
1.1%
6.0
2015
2.6%
72.3%
1.4%
2.4%
21.3%
-
1.5%
4.5%
54.2%
3.1%
9.5%
3.5%
6.0
2016
2.2%
72.3%
2.6%
1.8%
21.0%
-
1.1%
3.0%
54.9%
2.9%
11.2%
4.1%
6.0
2017
2.1%
71.5%
2.6%
2.5%
21.2%
-
1.0%
2.4%
49.0%
3.4%
14.6%
5.9%
6.1
2018
1.6%
72.8%
3.2%
2.2%
20.1%
-
1.9%
2.0%
37.6%
3.7%
19.0%
13.5%
6.5
2019
1.4%
72.1%
2.4%
2.4%
21.7%
-
1.5%
1.6%
26.1%
2.6%
27.5%
16.5%
6.8
2020
1.1%
68.3%
2.7%
3.3%
24.5%
-
1.8%
0.8%
17.3%
2.1%
28.8%
21.2%
7.1
2021
0.9%
67.0%
5.4%
5.4%
21.2%
-
3.2%
1.1%
12.2%
2.0%
32.5%
22.4%
7.0
2022
0.9%
65.2%
8.1%
5.7%
20.1%
-
5.0%
1.1%
8.7%
2.1%
33.8%
23.5%
7.1
2023
0.8%
59.9%
14.9%
5.5%
18.9%
-
9.9%
1.0%
8.3%
2.4%
29.9%
24.1%
7.1
2024 (prelim)
0.9%
56.6%
15.9%
7.5%
19.2%
-
11.5%
0.8%
8.6%
2.1%
29.3%
21.0%
6.9
~
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90
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Table 4.6. Production Share by Drive Technology
Model Year
Car
Truck
All
Front
Wheel
Drive
Rear
Wheel
Drive
Four
Wheel
Drive
Front
Wheel
Drive
Rear
Wheel
Drive
Four
Wheel
Drive
Front
Wheel
Drive
Rear
Wheel
Drive
Four
Wheel
Drive
1975
6.5%
93.5%
-
-
82.8%
17.2%
5.3%
91.4%
3.3%
1980
29.7%
69.4%
0.9%
1.4%
73.6%
25.0%
25.0%
70.1%
4.9%
1985
61.1%
36.8%
2.1%
7.3%
61.4%
31.3%
47.8%
42.9%
9.3%
1990
84.0%
15.0%
1.0%
15.8%
52.4%
31.8%
63.8%
26.1%
10.1%
1995
80.1%
18.8%
1.1%
18.4%
39.3%
42.3%
57.6%
26.3%
16.2%
2000
80.4%
17.7%
2.0%
20.0%
33.8%
46.3%
55.5%
24.3%
20.2%
2005
79.2%
14.2%
6.6%
20.1%
27.7%
52.2%
53.0%
20.2%
26.8%
2010
82.5%
11.2%
6.3%
20.9%
18.0%
61.0%
59.6%
13.7%
26.7%
2011
80.1%
11.3%
8.6%
17.7%
17.3%
65.0%
53.8%
13.8%
32.4%
2012
83.8%
8.8%
7.5%
20.9%
14.8%
64.3%
61.4%
10.9%
27.7%
2013
83.0%
9.3%
7.7%
18.1%
14.5%
67.5%
59.7%
11.1%
29.1%
2014
81.3%
10.6%
8.2%
17.5%
14.2%
68.3%
55.3%
12.1%
32.6%
2015
80.4%
9.7%
9.9%
16.0%
12.6%
71.4%
52.9%
10.9%
36.1%
2016
79.8%
9.1%
11.0%
15.9%
12.2%
72.0%
51.2%
10.5%
38.3%
2017
79.7%
8.3%
12.0%
16.1%
11.1%
72.8%
49.6%
9.6%
40.8%
2018
76.5%
9.4%
14.1%
13.4%
10.9%
75.6%
43.7%
10.2%
46.1%
2019
75.5%
10.1%
14.4%
14.4%
10.2%
75.4%
41.6%
10.1%
48.3%
2020
76.5%
8.8%
14.7%
12.5%
10.0%
77.5%
40.6%
9.4%
49.9%
2021
70.7%
11.2%
18.0%
8.5%
9.2%
82.3%
31.6%
10.0%
58.5%
2022
65.9%
11.2%
22.9%
10.0%
8.9%
81.0%
30.6%
9.8%
59.6%
2023
60.3%
14.9%
24.8%
9.5%
7.1%
83.4%
28.5%
10.1%
61.4%
2024 (prelim)
60.7%
12.3%
27.0%
9.1%
6.9%
84.0%
28.1%
8.9%
63.1%
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5. Manufacturer GHG Compliance
Manufacturers that produce passenger cars, light-duty trucks, and medium-duty passenger
vehicles for sale in the United States are required to meet greenhouse gas (GHG) emissions
and fuel economy standards. The Environmental Protection Agency (EPA) regulates
greenhouse gas (GHG) emissions through the light-duty GHG program, and the National
Highway Traffic Safety Administration (NHTSA) regulates fuel economy through the
Corporate Average Fuel Economy (CAFE) program. The following analysis is designed to
provide as much information as possible about how manufacturers are performing under
EPA's GHG program, including final compliance data through model year 2023 and credit
trades reported to EPA as of October 1, 2024.
This report reflects the current light-duty GHG and fuel economy regulations as finalized by
EPA and NHTSA, including updated standards through model year 2032 and 2031,
respectively. Any applicable regulatory changes finalized by EPA and NHTSA will be
included in future versions of this report.
Figure 5.1. The GHG Compliance Process
EPA's GHG program defines standards for
each manufacturer's car and truck fleets
based on the average footprint of the
vehicles produced for sale. Each
manufacturer fleet generates credits if the
fleet average emissions performance is below
the standards or generates deficits if
performance is above the standards. Credits,
or deficits, that manufacturers have accrued
in previous model years, credits earned as
part of the early credit program, credit trades,
credit forfeitures, and credit expirations are
also important components in determining
the final compliance status of each
manufacturer. Manufacturers that maintain a
positive, or zero, credit balance are
considered in compliance with the GHG program. Manufacturers that end any model year
with a deficit have up to three years to offset all deficits to avoid non-compliance and may
not report deficits for more than 3 years in a row. The general compliance process that
manufacturers follow at the end of each model year is shown in Figure 5.1.
1) Calculate
Model Year
Standards
2) Measure
Model Year
Performance
r
3) Evaluate Credits and Deficits
for each Model Year
Standards vs Performance
Credit Transactions
Credit Expirations
4) Determine Overall Credit
Balance and Compliance
Status
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Averaging, banking, and trading (ABT) provisions have been an important part of many
mobile source programs under the Clean Air Act. These provisions help manufacturers in
planning and implementing a phase-in of emissions reduction technology in their
production that is consistent with their unique redesign schedules. As part of the GHG
program, ABT provisions allow manufacturers to average their car or truck fleet CO2
emissions (i.e., the standards do not apply to individual vehicles), to earn and "bank" credits
by reducing their car or truck fleet performance to below the applicable standards, and to
trade credits between manufacturers. The net effect of the ABT provisions is that they
allow additional flexibility, encourage earlier introduction of emission reduction
technologies than might otherwise occur, and do so without reducing the overall
effectiveness of the program.
Manufacturer standards and model
year performance are discussed in
this report as per vehicle emission
rates, measured in grams of C02 per
mile (g/mi). Any discussion of
manufacturer total credit balances,
credit transactions, and compliance
will be in terms of total mass of CO2
emissions, measured in Megagrams
of CO2 (Mg). The use of a mass-based
metric enables the banking and
trading portions of the GHG program
by accounting for vehicle lifetime
emissions for all vehicles produced.
Converting from an emission rate to
total emissions is straightforward, as
shown in the box on the right.
Unlike the previous sections of this report, the tailpipe CO2 emission data presented in this
section are compliance data, based on EPA's City and Highway test procedures (referred to
as the "2-cycle" tests). These values should not be compared to the estimated real-world
data throughout the rest of this report. For a detailed discussion of the difference between
real-world and compliance data, see Appendix C. To download the data presented in this
section please see the report website: https://www.epa.gov/automotive-trends.
How to Calculate Total Emissions
from an Emission Rate
Total emissions, or credits, are calculated by multiplying a
C02 emission rate, the production volume of applicable
vehicles, and the expected lifetime vehicle miles travelled
(VMT) of those vehicles. To calculate total emissions, or
credits, the following equation is used:
Credits = ( CO2 Emissions x VMT x Production ) / 1,000,000
In the above equation, "Credits" are measured in
megagrams (Mg) of C02, "CO2 emissions" are measured in
grams per mile (g/mi), and "VMT" is in miles, and specified
in the regulations as 195,264 miles for cars and 225,865 for
trucks. To calculate g/mi from Mg:
CO2 Emissions = ( Credits x 1,000,000) / (VMT x Production )
When using these equations to calculate values for cars and
trucks in aggregate, use a production weighted average of
the car and truck VMT values. For the 2023 model year, the
industry wide weighted VMT is 214,384 miles.
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A. Footprint-Based CO2 Standards
At the end of each model year, manufacturers are required to calculate unique CO2
standards for their car and truck fleets, based on the vehicles produced that model year.
The GHG program uses footprint, which is the area between the four tires, as a metric for
determining the specific standard for each manufacturer's car and truck fleets.
Manufacturers must calculate new standards each year as the regulations become more
stringent, and as their footprint distribution and production change. See Section 3 for a
discussion of footprint and vehicle production trends and Appendix F for the definitions of
"car" and "truck" under the regulations.
Since the beginning of the GHG program, two notable changes in manufacturer groupings
have occurred. Porsche was part of the program as an independent manufacturer for
model years 2012 and 2013, but Porsche has been included as part of Volkswagen for all
following model years. Beginning in model year 2020, Lotus and Volvo submitted data as
one manufacturer for compliance with the GHG program, since both companies are
majority owned by Zhejiang Geely Holding Group Co., Ltd (Geely). EPA determinations
related to this merger are subject to change and will be updated in future reports as
necessary.
The regulations define footprint "curves" that provide a CO2 emissions target for every
vehicle footprint, as shown in Figure 5.2. For example, a car with a footprint of 47.7 square
feet in model year 2023 (the average car footprint) has a compliance C02 target of 170
g/mi. This is a target and not a standard, as there are no footprint-based CO2 emissions
requirements for individual vehicles at the time of certification. The unique CO2 standards
for each manufacturer's car and truck fleets are production-weighted averages of the CO2
target values, as determined from the curves, for all the unique footprint values of the
vehicles within that fleet. This is an element of the "averaging" approach of the ABT
provisions. Using one production-weighted average to define a single fleet standard allows
for some individual vehicles to be above that standard, while others are below.
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Figure 5.2. 2012-2023 Model Year CO2 Footprint Target Curves
400
350
CO
300-
O
CD
O
c
CO
^ 250
o
O
200
150
2012 Truck
2023 Truck
40
50 60
Footprint (sq ft)
70
80
The footprint curves for the 2012 and 2023 model years are shown in Figure 5.2. The GHG
targets have gradually decreased (become more stringent) from 2012 to the current 2023
levels, as defined in the regulations. Larger vehicles have higher targets, although the
increases are capped beyond a certain footprint size (i.e., the curves become flat). Trucks
have higher targets than cars of the same footprint in the same model year.
In addition to the footprint-based standards, EPA established several alternative standards
for small to intermediate manufacturers. These provisions provide additional lead-time for
manufacturers that may not be able to take full advantage of averaging or other program
flexibilities due to the limited scope of the vehicles they sell.
The Temporary Lead-time Allowance Alternative Standards (TLAAS) provisions were
available to manufacturers with production of less than 400,000 vehicles in model year
2009. This provision allowed manufacturers to place vehicles in an alternative car or truck
TLAAS fleet each model year, with those vehicles subject to a less stringent standard. The
standard for a TLAAS fleet was 1.25 times the standard that would have applied to that
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fleet according to the footprint-based approach applied to all other car and truck fleets.
Each manufacturer could apply the TLAAS standards to a maximum of 100,000 vehicles,
cumulative over model years 2012-2015. Mercedes, Jaguar Land Rover, Volvo, Porsche,
Ferrari, Aston Martin, Lotus, and McLaren participated in the TLAAS program. The overall
industry-wide impact of the TLAAS program was less than 1 g/mi for all years it was
available.
The intermediate volume provisions allowed intermediate volume manufacturers (those
that produced less than 50,000 vehicles in the 2009 model year) to use an alternative
compliance schedule in model years 2017-2020. Under these provisions, manufacturers
were required to meet the model year 2016 standards in the model years 2017 and 2018,
delay meeting the 2019-2020 standards by one model year, and finally align with the
primary standards and other manufacturers in the 2021 model year. Jaguar Land Rover
and Volvo are the two manufacturers that utilized these alternative compliance schedules.
Small volume manufacturers, with U.S. production of less than 5,000 vehicles per year,
have additional options under the GHG program. This includes the ability to petition EPA
for alternative standards for model year 2017 and later and allowing these manufacturers
to meet an established alternative model year 2017 standard in model years 2015 and
2016. Aston Martin, Ferrari, Lotus, and McLaren applied for unique alternative standards
for model years 2017-2021, and EPA established alternative standards for these
manufacturers in a July 2020 determination.18 These manufacturers submitted petitions for
alternative standards for model year 2022 and beyond, and in 2024 EPA codified19 that the
applicable 2021 model year small volume manufacturer standards will continue for five
additional model years, through the 2026 model year. Lotus is no longer eligible for a small
volume manufacturer alternative standard as the company is now majority owned by
Geely, along with Volvo.
Each manufacturer's standards for model year 2023 are shown in Table 5.1. In model year
2023, average new car footprint increased 0.5 square feet while truck footprint increased
0.1 square feet. The more stringent model year 2023 footprint targets, along with changes
to footprint, resulted in a reduction of the car standard by 14 g/mi, from 183 g/mi to 170
g/mi, and the truck standard by 27 g/mi, from 260 g/mi to 234 g/mi. While there is no
combined car and truck standard for regulatory purposes, this report will often calculate
one to provide an overall view of the industry and to allow comparison across
18 89 FR 39561, July 1, 2020.
19 89 FR 27927, April 18, 2024.
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manufacturers. Overall, the effective combined car and truck standard decreased in model
year 2023 by 23 g/mi, from 234 g/mi to 212 g/mi.
Table 5.1 shows the manufacturers that produced vehicles in model year 2023 using
current manufacturer groupings, while later tables in this report show all manufacturers
that were regulated independently in any model year, to allow for complete credit
accounting.
Table 5.1. Manufacturer Footprint and Standards for Model Year 2023
Manufacturer
Footprint (ft2)
Standards (g/mi)
Car
Truck
All
Car
Truck
All
Aston Martin
48.8
55.4
52.0
376
376
376
BMW
48.6
52.0
50.2
173
225
200
Ferrari
47.7
-
47.7
373
-
373
Fisker
53.8
-
53.8
191
-
191
Ford
49.2
59.2
58.2
175
253
246
GM
46.4
59.0
55.7
165
253
232
Honda
46.9
51.9
49.4
167
225
198
Hyundai
47.6
50.3
48.7
169
218
190
Jaguar Land Rover
46.5
53.5
53.4
165
231
230
Kia
46.2
50.0
47.9
164
217
190
Lucid
53.2
-
53.2
189
-
189
Mazda
44.0
47.0
46.7
160
205
201
McLaren
46.6
-
46.6
329
-
329
Mercedes
50.7
53.9
52.3
179
232
207
Mitsubishi
38.7
45.6
44.7
146
200
194
Nissan
46.6
50.6
48.4
165
219
191
Rivian
-
59.5
59.5
-
255
255
Stellantis
52.8
56.6
56.0
188
243
236
Subaru
45.0
46.2
46.0
160
202
197
Tesla
50.7
51.5
50.7
180
223
184
Toyota
46.9
52.6
50.4
167
227
206
vw
46.5
50.3
48.8
165
218
199
Volvo
48.0
51.2
50.2
170
222
206
All Manufacturers
47.7
54.2
51.8
170
234
212
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B. Model Year Performance
After determining car and truck fleet standards for the model year, manufacturers must
determine the performance value for their car and truck fleets. This is the average
production-weighted CO2 tailpipe emissions of each fleet, including the impact of several
optional performance credits and adjustments. These credits and adjustments allow
manufacturers to benefit from technologies that reduce emissions but are not wholly
captured in standard regulatory tests, provide incentives for manufacturers to adopt
advanced technologies, and provide flexibility in other areas of the program. The available
performance credits and adjustments include:
Performance credits for producing alternative fuel vehicles
Performance credits for improving air conditioning systems
Performance credits for deploying "off-cycle" technologies that reduce emissions
but are not captured on EPA's regulatory test cycles
Adjustments for utilizing alternate methane and nitrous oxide standards
The impact of these credits and adjustments are integral to the annual model year analysis.
Any performance credits generated must be included in the model year fleet calculations
before a manufacturer can bank or trade credits. In addition, the performance value,
including the impact of the performance credits and adjustments, is the most accurate way
to compare how manufacturers' car and truck fleets are performing in comparison to the
standards within a model year. The standards discussed previously were designed
assuming manufacturers would use these optional provisions; therefore, any comparison
that excludes them is incomplete. Manufacturer tailpipe emissions, and each of the
performance credits and adjustments, are examined in detail below.
Tailpipe CO2 Emissions
The starting point for determining compliance for each manufacturer is its "2-cycle" tailpipe
GHG emissions value. All manufacturers are required to test their vehicles on the Federal
Test Procedure (known as the "City" test) and the Highway Fuel Economy Test (the
"Highway" test). Results from these two tests are combined by weighting the City test by
55% and the Highway test by 45%, to achieve a single combined C02 value for each vehicle
model. Manufacturers then calculate a sales-weighted average of all the combined
city/highway values for each car and truck fleet. This represents the measured tailpipe CO2
emissions of a fleet without the application of any additional performance credits. As
discussed previously in this report, 2-cycle tailpipe CO2 emissions should only be used in
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the context of the compliance regulations and are not the same as and should not be
compared to the estimated real-world values reported in Sections 1-4.
As part of the GHG program, electric vehicles and fuel cell vehicles are included in the 2-
cycle tailpipe calculations with zero g/mi of tailpipe emissions. Plug-in hybrid vehicles
(PHEVs) are allowed to use a zero g/mi value for the portion of operation attributed to the
use of grid electricity (i.e., only emissions from the portion of operation attributed to the
gasoline engine are counted). Use of the zero g/mi option was limited to the first 200,000
qualified vehicles produced by a manufacturer in the 2012-2016 model years. No
manufacturer reached this limit. In the 2017-2032 model years, manufacturers may
continue to use zero g/mi for these vehicles, without any limits.
Figure 5.3 shows the 2-cycle tailpipe emissions reported by each manufacturer for the 2012
and 2023 model years, for all vehicles and for car and truck fleets. Companies that produce
solely electric vehicles (Tesla) are shown separately in the figure because they produce zero
tailpipe emissions on the 2-cycle tests. Figure 5.3 includes all manufacturers that reported
production in 2012 and 2023; there are additional manufacturers that produced vehicles in
that timespan that are not shown. The tailpipe values in Figure 5.3 should not be directly
compared to the manufacturer's standards presented in Table 5.1, as the standards were
created taking into consideration the optional performance credits available to
manufacturers to reduce their performance values.
Every manufacturer that has been in the U.S. market since the GHG program was
implemented in 2012 has reduced fleetwide overall tailpipe GHG emissions, except for
those manufacturers that only produce electric vehicles. Compared to the first year of the
program, Volvo leads manufacturers in the overall reduction of 2-cycle CO2 emissions with
a reduction in their average new vehicle emission rate of 119 g/mi, or 38%. Eleven
manufacturers have reduced tailpipe CO2 emissions by 10% or more. Overall, tailpipe CO2
emissions of the entire fleet have been reduced by 53 g/mi, or about 17%, since the 2012
model year. Compliance is assessed on a fleet-specific basis, and most manufacturers have
reduced emissions within their car and truck fleets, some considerably, leading to
reductions of 82 g/mi in each of the car and truck fleets since model year 2012.
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Figure 5.3. Changes in 2-Cycle Tailpipe CO2 Emissions by Manufacturer
All Car
Truck
Tesla
Volvo
Mitsubishi
Kia
Hyundai
Nissan
BMW
Subaru
Honda
Mercedes
Toyota
VW
Mazda
Ford
GM
Stellantis
Jaguar Land Rover
Ferrari
All.
Manufacturers
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Performance Credits for Producing Alternative Fuel Vehicles
EPA's GHG program provides performance credits for dedicated and dual fuel alternative
fuel vehicles. Dedicated alternative fuel vehicles run exclusively on an alternative fuel while
dual fuel vehicles can run both on an alternative fuel and on conventional gasoline. This
section describes two pathways for manufacturers to benefit from the production of
alternative fuel vehicles. The first pathway is through a set of defined production
multipliers available for certain alternative fuel vehicles. The second pathway is based on
incentives for gasoline-ethanol flexible fuel vehicles (FFVs), which can run on E85 (85%
ethanol and 15% gasoline), or on conventional gasoline.
Performance Credits for Advanced Technology Vehicles
The GHG program created an incentive for advanced technology vehicles through the
introduction of vehicle "multipliers" for electric vehicles (BEVs), plug-in hybrid electric
vehicles (PHEVs), fuel cell electric vehicles (FCEVs), and compressed natural gas (CNG)
vehicles. Multipliers allow manufacturers to increase the volume of credits created by each
vehicle during the compliance process. For example, the 1.5 multiplier for 2023 model year
BEVs allows manufacturers to increase the credits created by each electric or fuel cell
vehicle by an additional 50%. In model years 2023 and 2024, BEVs, FCEVs, and PHEVs are
eligible for production multipliers subject to a cumulative credit cap of 10 g/mi per
manufacturer across both model years. Previous model years where multipliers were
available did not have a cap. Advanced technology multiplier credits will be evaluated again
after the 2024 model year to ensure accuracy and consistency with regards to the credit
cap.
The impact of the multipliers is calculated separately from the main car or truck fleet of
each manufacturer and is included in this report as an advanced technology credit. The
multipliers established by rulemaking are shown in Table 5.2.
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Table 5.2. Production Multipliers by Model Year
Model
Year
2017
2018
2019
2020
2021
2022
Electric Vehicles
and Fuel Cell Vehicles
Plug-In Hybrid Electric
Vehicles
Dedicated and Dual-
Fuel Natural Gas
Vehicles
2.0
2.0
2.0
1.75
1.5
1.6
1.6
1.6
1.45
1.3
1.6
1.6
1.6
1.45
1.3
2.0
2023-2024
2025+
None
1.5
None
None
1.3
None
None
None
Figure 5.4 shows the model year 2023 production volume of vehicles that are in categories
that qualify for model year 2023 incentives. More than 1.6 million BEVs, PHEVs, and FCEVs
were produced in the 2023 model year. Of those vehicles, about 85% were BEVs, 15% were
PHEVs, and less than 1 % were FCEVs. Figure 4.15 in the previous section shows the overall
growth in BEVs, PHEVs, and FCEVs. The impacts of the advanced technology multiplier
credit are shown in Figure 5.5. Eight manufacturers reached the capped multiplier credit
threshold of 10 g/mi while one, BMW, elected to take less than the maximum credit
allowance, leaving room for credit generation in the 2024 model year.
EPA finalized a technical amendment on March 31, 2020 that corrects the regulations
pertaining to how manufacturers calculate credits for the GHG program's advanced
technology incentives. Manufacturers that produced vehicles eligible for these incentives
have resubmitted 2-cycle data to EPA, and this report uses these updated data and
calculations.
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Figure 5.4. Model Year 2023 Production of BEVs, PHEVs, and FCEVs
800-
700-
600-
O 500-
O,
.1 400-
+-I
o
3
T3
O 300-
CL
200-
100-
0-
Figure 5.5. Model Year 2023 Advanced Technology Credits by Manufacturer
10.0-
¦ Battery Electric Vehicle
¦ Plug-In Hybrid Electric Vehicle
Fuel Cell Electric Vehicle
l_
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Gasoline-Ethanol Flexible Fuel Vehicles
For the 2012 to 2015 model years, FFVs could earn performance credits corresponding to
the fuel economy credits under CAFE. For both programs, it was assumed that FFVs
operated half of the time on each fuel. The GHG credits were based on the arithmetic
average of alternative fuel and conventional fuel CO2 emissions. Further, to fully align the
GHG credit with the CAFE program, the CO2 emissions measurement on the alternative fuel
was multiplied by 0.15. The 0.15 factor was used because, under the CAFE program's
implementing statutes, a gallon of alternative fuel is deemed to contain 0.15 gallons of
gasoline fuel, and the E85 fuel economy is divided by 0.15 before being averaged with the
gasoline fuel economy.
Starting in model year 2016, GHG compliance values for FFVs are based on the actual
emissions performance of the FFV on each fuel, weighted by EPA's assessment of the actual
use of these fuels in FFVs. In 2014, EPA issued a determination defining an "F factor" of 0.14
to use when weighting E85 and gasoline CO2 emissions for the 2016-2018 model years
FFVs; this reflects EPA's estimate that FFVs would be operating 14% of the time on E85. This
approach is comparable to the "utility factor" method used to weight gasoline and
electricity for PHEVs, which projects the percentage of miles that a PHEV will drive using
electricity based on how many miles a fully charged PHEV can drive using grid electricity.
EPA also adopted an F-factor of 0.14 for model years 2019 and 2020, and in a separate
action has extended the use of 0.14 to model years 2021 and later.20 This value will
continue to apply until EPA issues a new determination.
FFVs can still represent a CO2 emissions benefit and can help to lower the emissions of a
manufacturer's fleet, but the overall impact is significantly diminished. Because the FFV
values now incorporate the slightly lower CO2 emissions when operating on E85 (typically
1 -3% lower than on gasoline), and a realistic rate of E85 fuel use, the benefit from FFVs is
no longer of the same magnitude that it was through the 2015 model year. Thus, we are no
longer illustrating a g/mi benefit to manufacturers specific to producing FFVs. The impact of
E85, a lower-GHG fuel than gasoline, is inseparable from, and built into, the 2-cycle
emissions described earlier.
20 "E85 Flexible Fuel Vehicle Weighting Factor for Model Years 2020 and Later Vehicles," EPA Office of Air and
Radiation, CD-20-12.
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Performance Credits for Improved Air Conditioning Systems
Almost all new cars and light trucks in the United States are equipped with air conditioning
(A/C) systems. There are two mechanisms by which A/C systems contribute to the
emissions of greenhouse gases: through leakage of hydrofluorocarbon (HFC) refrigerants
(i.e., "direct" emissions) and through the combustion of fuel to provide mechanical power
to the A/C system (i.e., "indirect" emissions). The EPA 2-cycle compliance tests do not
measure either A/C refrigerant leakage or the increase in tailpipe emissions attributable to
the additional engine load of A/C systems. Thus, the GHG emission regulations include a
provision that allows manufacturers to earn optional credits for implementing technologies
that reduce either type of A/C-related emissions.
Air Conditioning Leakage Performance Credits
Refrigerants used in automotive air conditioning systems can have high global warming
potentials (GWP)21, such that leakage of a small amount of refrigerant can have a far
greater impact on global warming than emissions of a similar mass of CO2. The impacts of
refrigerant leakage can be reduced significantly by using systems with leak-tight
components, by using a refrigerant with a lower GWP, or by implementing both
approaches.
A manufacturer choosing to generate A/C leakage credits is required to calculate a leakage
"score" for the specific A/C system. This score is based on the number, performance, and
technology of the components, fittings, seals, and hoses of the A/C system and is calculated
as refrigerant emissions in grams per year, using the procedures specified by the SAE
Surface Vehicle Standard J2727. The score is then converted to a g/mi credit value based on
the GWP of the refrigerant. In model year 2012, all leakage credits were based on
improvements to the A/C system components (e.g., O-rings, seals, valves, and fittings).
In model year 2013, GM and Honda introduced vehicles using a refrigerant with a
significantly reduced GWP. This new refrigerant, HFO-1234yf, has a GWP of 4, compared to
a GWP of 1430 for the predominant refrigerant at the time, HFC-134a, as illustrated in
Figure 5.6. In the nine model years since, low GWP refrigerant use has expanded to 97% of
new vehicles. All manufacturers reported some type of A/C leakage credits in the 2023
model year, resulting in an overall performance credit of 15.4 g/mi for the industry.
21 The global warming potential (GWP) represents how much a given mass of a chemical contributes to global
warming over a given time period compared to the same mass of C02. The GWP of C02 is 1.0.
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Figure 5.6. HFO-1234yf Adoption by Manufacturer
100%
75%
<1)
&_
05
sz
CD
.2 50%
o
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o
25%
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Model Year
Air Conditioning Efficiency Performance Credits
The A/C system also contributes to increased tailpipe CO2 emissions through the additional
work required by the engine to operate the compressor, fans, and blowers. This power
demand is ultimately met by using additional fuel, which is converted into CO2 by the
engine during combustion and exhausted through the tailpipe. Increasing the overall
efficiency of an A/C system reduces the additional load on the engine from A/C operation,
and thereby leads to a reduction in fuel consumption and a commensurate reduction in
GHG emissions.
Most of the additional load on the engine from A/C systems comes from the compressor,
which pressurizes the refrigerant and pumps it around the system loop. A significant
additional load may also come from electric or hydraulic fans, which move air across the
condenser, and from the electric blower, which moves air across the evaporator and into
the cabin. Manufacturers have several options for improving efficiency, including more
efficient compressors, fans, and motors, and system controls that avoid over-chilling the air
(and subsequently re-heating it to provide the desired air temperature). For vehicles
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equipped with automatic climate-control systems, real-time adjustment of several aspects
of the overall system can result in improved efficiency.
The regulations provide manufacturers with a menu of A/C system technologies and
associated credit values (in g/mi of CO2), some of which are described above. These credits
are capped at 5.7 g/mi for all vehicles in model years 2012-2016, and at 5.0 and 7.2 g/mi
for cars and trucks, respectively, in model year 2017 and later. Twenty out of twenty-two
manufacturers reported A/C efficiency credits in model year 2023, resulting in an average
credit of 5.8 g/mi for the industry.
Air Conditioning Performance Credit Summary
A summary of the A/C leakage and efficiency performance credits reported by the industry
is shown in Figure 5.7. Leakage credits have been more prevalent than efficiency credits,
but both credit types are growing in use.
Figure 5.8 shows the benefit of A/C credits, for each manufacturer's fleet for the 2023
model year. All manufacturers used the A/C credit provisionsleakage reductions,
efficiency improvements, or bothas part of their compliance demonstration in the 2023
model year. Ford had the highest reported credit on a per vehicle g/mi basis, at 23.9 g/mi.
Thus, A/C credits resulted in about an 8% reduction from tailpipe emissions for Ford. All
manufacturers reported at least 12 g/mi of credits, and the overall industry reported an
average of 21.2 g/mi of total A/C credits (5.8 g/mi from efficiency improvements and 15.4
from leakage reductions).
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Figure 5.7. Fleetwide A/C Credits by Credit Type
25-
20-
3 15
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xs
a>
O
o 10.
X
o
0-
Credit Source
A/C Efficiency
¦ A/C Leakage
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Model Year
Figure 5.8. Total A/C Credits by Manufacturer for Model Year 2023
25
20
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3 15
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Performance Credits for "Off-Cycle" Technology
In some cases, manufacturers employ technologies that result in CO2 emission reductions
that are not adequately captured on the 2-cycle test procedures. These benefits are
acknowledged in EPA's regulations by giving manufacturers three pathways by which to
accrue "off-cycle" performance credits. The first, and most widely used, pathway is a
predetermined list or "menu" of credit values for specific off-cycle technologies. The second
pathway is to use a broader array of emissions testing (5-cycle testing) to demonstrate the
C02 emission reduction. The third pathway allows manufacturers to seek EPA approval to
use an alternative methodology to demonstrate CO2 emission reductions.
Off-Cycle Performance Credits Based on the Menu
The first pathway to generating off-cycle credits is for a manufacturer to install
technologies from a predetermined list or "menu" of technologies preapproved by EPA. The
off-cycle credit menu provides specific credit values, or the calculation method for such
values, for each technology.22 Technologies from the menu may be used beginning in
model year 2014. This pathway allows manufacturers to use conservative credit values
established by EPA for a wide range of off-cycle technologies, with minimal data submittal
or testing requirements.
The regulations clearly define each technology and any requirements that apply for the
technology to generate credits. Figure 5.9 shows the adoption of menu technologies, by
manufacturer. The amount of credit awarded varies for each technology and between cars
and trucks. The impact of credits from this pathway on a manufacturer's fleet was capped
at 10 g/mi through model year 2022, meaning that any single vehicle might accumulate
more than 10 g/mi, but the cumulative effect on a single manufacturer's fleet may not
exceed a credit of more than 10 g/mi. The manufacturer cap increased to 15 g/mi for
model year 2023 through 2026 before reverting to 10 g/mi through model year 2030, then
phasing out entirely in model year 2033. Manufacturers will no longer be able to generate
credits under this method for vehicles with zero tailpipe emissions beginning in model year
2027.
Off-cycle technology credits based on the menu were widely used in model year 2023, with
more than 95% of off-cycle credits generated via the menu pathway. Each of these
technologies is discussed below.
: See 40CFR 86.1869-12(b).
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Figure 5.9. Off-Cycle Menu Technology Adoption by Manufacturer, Model Year
2023
Aston Martin -
BMW-
Ferrari -
Fisker -
Ford -
GM -
Honda -
Hyundai -
Jaguar Land Rover -
Kia -
Lucid -
Mazda -
McLaren -
Mercedes -
Mitsubishi -
Nissan -
Rivian -
Stellantis -
Subaru -
Tesla -
Toyota -
VW-
Volvo -
All Manufacturers -
24%
82%
34%
100% 21%
53%
96%
100%
26%
83%
84%
44%
100%
97% 18%
87% 32%
55% 12%
31% 100% 31%
99% 67%
17% 100% 22%
100% 100% 100%
93% 21%
7%
100%
100%
100%
100% 100%
100%
100% 100%
17%
100% 100%
66%
20%
68%
79%
28%
64%
29%
91%
59%
12%
100%
48%
90%
82%
15%
56%
66%
82%
100%
51%
20%
29%
0%
42%
35%
6%
21%
5%
100% 100%
12%
34%
100%
100%
100% 89%
98%
91%
100%
99%
100%
44%
100%
100%
90%
43%
76%
90%
30%
38%
91%
45%
87%
78%
i? /o
78%
10%
82%
17%
59%
43%
91%
98%
100%
100%
100%
59%
85%
26%
100%
26%
76%
69%
48%
90%
44%
7%
94%
no/.
71%
84%
72%
100%
100%
100%
100%
28%
12%
58%
15%
39%
50%
70%
94%
46%
1%
25%
90%
21%
3%
66%
81%
85%
99%
100%
20%
96%
100%
26%
45%
79%
63%
100%
60%
34%
20%
90%
25%
14%
51%
10%
62%
62%
89%
0%
0%
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Active Aerodynamics
Active aerodynamics refers to technologies which are automatically activated to improve
the aerodynamics of a vehicle under certain conditions. These include grill shutters and
spoilers, which allow air to flow over and around the vehicle more efficiently, and
suspension systems that improve air flow at higher speeds by reducing the height of the
vehicle. Credits are variable and based on the measured improvement in the coefficient of
drag, a test metric that reflects the efficiency of airflow around a vehicle. Most
manufacturers implemented at least some level of active aerodynamics on their model
year 2023 vehicles. Fisker, Lucid, and Tesla all reported implementation of active
aerodynamics on 100% of their new vehicles. Overall, 60% of new vehicles qualified for
these credits, reducing overall fleet CO2 emissions by 0.7 g/mi.
Thermal Control Technologies
Thermal control systems help to maintain a comfortable air temperature of the vehicle
interior, without the use of the A/C system. These technologies lower the load on the A/C
system and thus the amount of fuel required to run the A/C system, subsequently lowering
GHG tailpipe emissions. The thermal control technologies included in the off-cycle menu
are:
Active and passive cabin ventilation - Active systems use mechanical means to
vent the interior, while passive systems rely on ventilation through convective air
flow. Credits available for this technology range from 1.7 to 2.8 g/mi.
Active seat ventilation - These systems move air through the seating surface,
transferring heat away from the vehicle occupants. Credits are 1.0 g/mi for cars
and 1.3 g/mi for trucks.
Glass or glazing - Credits are available for glass or glazing technologies that
reduce the total solar transmittance through the glass, thus reducing the heat
from the sun that reaches the occupants. The credits are calculated based on
the measured solar transmittance through the glass and on the total area of
glass on the vehicle.
Solar reflective surface coating - Credits are available for solar reflective surface
coating (e.g., paint) that reflects at least 65% of the infrared solar energy. Credits
are 0.4 g/mi for cars and 0.5 g/mi for trucks.
Active cabin ventilation was installed on 34% of all new vehicles in model year 2023, with
six manufacturers reporting this technology on all of their vehicles. Five manufacturers
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reporting using passive cabin ventilation on all model year 2023 production, and overall
passive cabin ventilation had a 25% adoption rate.
Active seat ventilation was used by many manufacturers and the rate of implementation
remained about the same at 20% in model year 2023. Lucid and Rivian utilized active seat
ventilation in all of their model year 2023 vehicles, followed by Jaguar Land Rover at 67%.
Glass or glazing technology continues to be used throughout the industry, with 90% of
model year 2023 vehicles equipped with these technologies. Solar reflective coatings have
been used less widely, with a penetration of 14% across new vehicles in model year 2023,
and no manufacturer above 30%.
Due to the likelihood of synergistic effects among the various thermal technologies, the
total credit allowed from this technology group is capped at 3.0 g/mi for cars and 4.3 g/mi
for trucks. Overall, manufacturers widely adopted thermal control technologies, which
reduced model year 2023 overall new vehicle fleet CO2 emissions by 2.3 g/mi.
Active Engine and Transmission Warmup
Active engine and transmission warmup systems use heat from the vehicle that would
typically be wasted (exhaust heat, for example) to warm up key elements of the engine,
allowing a faster transition to more efficient operation. An engine or transmission at its
optimal operating temperature minimizes internal friction, and thus operates more
efficiently and reduces tailpipe C02 emissions. Systems that use a single heat-exchanging
loop that serves both transmission and engine warmup functions are eligible for either
engine or transmission warmup credits, but not both. Active engine and transmission
warmup technologies are each worth credit up to 1.5 g/mi for cars and 3.2 g/mi for trucks.
Most manufacturers adopted warmup technologies for their engines, transmissions, or
both. Active engine warmup was installed in 51 % of all new vehicles, and active
transmission warmup in 10% of the fleet, resulting in a CO2 reduction of about 1.7 g/mi
across the 2023 model year fleet. Honda and Stellantis led the industry in active engine
warmup, with more than 75% of their new vehicles employing the technology. McLaren led
the industry in active transmission warmup technologies, with 100% of their new vehicles
utilizing these technologies.
Engine Idle Stop/Start
Engine idle stop/start systems allow the engine to turn off when the vehicle is at a stop,
automatically restarting the engine when the driver releases the brake and/or applies
pressure to the accelerator. If equipped with a switch to disable the system, EPA must
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determine that the predominant operating mode of the system is the "on" setting
(defaulting to "on" every time the key is turned on is one basis for such a determination).
Thus, some vehicles with these systems are not eligible for credits. Credits range from 1.5
to 4.4 g/mi and depend on whether the system is equipped with an additional technology
that, at low ambient temperatures, allows heat to continue to be circulated to the vehicle
occupants when the engine is off during a stop-start event.
The implementation of stop/start has been increasing rapidly, as discussed in Section 4,
which aggregates and reports on these systems regardless of the regulatory eligibility for
credits. In model year 2023, 62% of new vehicles qualified for and claimed this credit,
resulting in a fleetwide CO2 reduction of about 2.3 g/mi. Eighteen manufacturers installed
stop start systems on at least some of their 2023 vehicles.
High Efficiency Exterior Lights
High efficiency lights (e.g., LEDs) reduce the total electric demand, and thus the fuel
consumption and related GHG emissions, of a lighting system in comparison to
conventional incandescent lighting. Credits are based on the specific lighting locations,
ranging from 0.05 g/mi for high beams to 0.38 g/mi for low beams. The total of all lighting
credits summed from all lighting locations may not exceed 1.0 g/mi.
Unlike some other off-cycle technologies, safety regulations require that all vehicles must
be equipped with lights, and the popularity of high efficiency lights across manufacturers
may reflect that lighting improvements are relatively straightforward to implement. Most
manufacturers reported wide-spread usage of high efficiency lighting in model year 2023
new vehicles, except Mazda, and Mitsubishi. Overall, in model year 2023, 89% of new
vehicles implemented high efficiency lighting in some form, reducing fleetwide CO2
emissions by 0.6 g/mi.
High Efficiency Alternators
Alternators convert mechanical energy from an engine into electrical energy, which is used
to power the vehicle's electrical system and accessories. High efficiency alternators reduce
the amount of mechanical energy needed to drive the alternator and provide the necessary
electrical requirements of the vehicle. High efficiency alternators were added as an off-
cycle menu option beginning in model year 2020. Fifteen manufacturers claimed menu
credits for high-efficiency alternators on 62% of all new vehicles, reducing fleetwide CO2
emissions by 0.7 g/mi. Stellantis, Jaguar Land Rover, and Toyota also claimed credits for
high-efficiency alternators in model year 2023 through the alternative methodology
described below.
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Solar Panels
Vehicles that use electric motors for propulsion, such as battery electric, plug-in hybrid
electric, and hybrid electric vehicles may receive credits for solar panels that are used to
charge the battery directly or to provide power directly to essential vehicle systems (e.g.,
heating and cooling systems). Credits are based on the rated power of the solar panels.
Fisker was the only manufacturer that claimed this credit in model year 2023.
Summary of Off-Cycle Menu-Based Performance Credits
As shown in Table 5.3, manufacturers are using a mix of off-cycle menu technologies,
though each uses and benefits from the individual technologies to differing degrees. In
model year 2023, the industry achieved 8.2 g/mi of credits from the menu, based on a
production weighted average of credits across all manufacturers. The effective off-cycle
menu credit cap for 2023 model year was increased to 15 g/mi from 10 g/mi in the 2022
model year. Multiple manufacturers including Volvo, Jaguar Land Rover, GM, Ford, Fisker
and BMW, achieved or exceeded 10 g/mi while no manufacturers exceeded the 15 g/mi off-
cycle menu credit cap. The overall industry-wide value of 8.2 g/mi reflects all off-cycle menu
credits submitted by manufacturers. The off-cycle menu credit cap will remain at 15 g/mile
through 2026 model year then phase out to 0 g/mi in the 2033 model year.
Off-Cycle Performance Credits Based on 5-Cycle Testing
In cases where additional laboratory testing can demonstrate emission benefits, a second
pathway allows manufacturers to use a broader array of emission tests (known as "5-cycle"
testing because the methodology uses five different testing procedures) to demonstrate
and justify off-cycle CO2 credits.23 The additional emission tests allow emission benefits to
be demonstrated over elements of real-world driving not captured by the GHG compliance
tests, including high speeds, rapid accelerations, and cold temperatures. Credits
determined according to this methodology do not undergo additional public review.
Manufacturers will no longer be able to generate credits under this method beginning in
model year 2027.
1 See 40CFR 86.1869-12(c).
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Table 5.3. Model Year 2023 Off-Cycle Technology Credits from the Menu, by Manufacturer and Technology
(g/mi)
Active
Active
Active
High
High
Total
Aero-
Thermal
Engine
Trans
Engine
Efficiency
Efficiency
Solar
Menu
Manufacturer
dynamics
Controls
Warmup
Warmup
Stop-Start Alternator
Lighting
Panels
Credits
Aston Martin
0.2
-
-
0.5
2.0
-
0.3
-
2.9
BMW
1.3
3.3
0.8
-
2.8
0.8
1.0
-
10.0
Ferrari
-
0.3
-
-
-
-
1.0
-
1.3
Fisker
0.8
-
-
-
-
-
1.0
12.1
13.9
Ford
1.5
2.5
2.1
0.6
2.9
1.0
0.6
-
11.2
GM
0.9
2.1
1.8
0.9
3.8
0.5
0.8
-
10.7
Honda
0.3
1.3
2.4
0.9
2.9
0.4
0.5
-
8.8
Hyundai
0.2
2.2
1.4
-
1.7
1.0
0.4
-
6.9
Jaguar Land Rover
1.6
2.7
-
-
4.4
0.6
0.5
-
9.7
Kia
0.3
2.6
1.3
0.0
1.5
0.7
0.2
-
6.6
Lucid
0.9
3.0
-
-
-
-
1.0
-
4.9
Mazda
0.7
4.0
0.7
-
0.2
0.1
-
-
5.7
McLaren
0.1
-
-
1.5
1.5
-
0.8
-
3.9
Mercedes
-
3.0
-
-
1.3
-
0.9
-
5.2
Mitsubishi
0.4
1.0
-
-
0.4
0.5
-
-
2.3
Nissan
0.7
1.2
1.4
-
1.1
1.5
0.6
-
6.5
Rivian
-
2.9
-
-
-
-
0.7
-
3.6
Stellantis
0.8
2.3
2.3
-
3.1
0.7
0.3
-
9.6
Subaru
0.2
1.3
-
0.0
2.1
0.7
0.4
-
4.7
Tesla
1.1
3.1
-
-
-
-
0.7
-
4.9
Toyota
0.2
2.6
1.2
-
1.8
0.6
0.6
0.0
7.0
Volkswagen
0.3
2.5
1.7
-
2.8
1.5
0.8
-
9.6
Volvo
-
3.6
1.3
-
3.4
1.4
1.0
-
10.7
All
0.7
2.3
1.5
0.3
2.3
0.7
0.6
0.0
8.2
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GM is the only manufacturer to date to have claimed off-cycle credits based on 5-cycle
testing. These credits are for an auxiliary electric pump used on certain GM gasoline-
electric hybrid vehicles to keep engine coolant circulating in cold weather while the vehicle
is stopped, and the engine is off. This enables the engine stop-start system to turn off the
engine more often during cold weather, while maintaining a comfortable temperature
inside the vehicle. GM received off-cycle credits during the early credits program for
equipping hybrid full size pick-up trucks with this technology and has since applied the
technology to several other vehicles through model year 2017. They did not claim credits
for this technology in model year 2023.
Off-Cycle Performance Credits Based on an Alternative Methodology
This third pathway for off-cycle technology performance credits allows manufacturers to
seek EPA approval to use an alternative methodology for determining off-cycle technology
C02 credits.24 This option is only available if the benefit of the technology cannot be
adequately demonstrated using the 5-cycle methodology. Manufacturers may also use this
option for model years prior to 2014 to demonstrate CO2 reductions for technologies that
are on the off-cycle menu, or reductions that exceed those available via use of the menu.
The regulations require that EPA seek public comment on and publish each manufacturer's
application for credits sought using this pathway.
After reviewing the petitions submitted by manufacturers, EPA drafts and publishes
decision documents that explain the impacts and applicability of the unique alternative
method technologies via the Federal Register. Each alternative methodology Federal
Register notice and technology explanation can be found through the following EPA
website: https://www.epa.gov/ve-certification/compliance-information-light-duty-
greenhouse-gas-ghg-standards. To date, thirteen manufacturers have applied for and
received credits for technologies through alternative methodologies. Several applications
request credits for technologies initially submitted by other manufacturers, thus, more
than one manufacturer may ultimately request credits for similar technology.
Manufacturers will no longer be able to generate credits under this method beginning in
model year 2027.
The off-cycle technologies that have been approved to date under the alternative pathway
include:
^ See 40CFR 86.1869-12(d).
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Menu technologies (alternative values or retroactive credits)
EPA has approved credit requests for retroactive credits back to model year 2012, or for
manufacturers that have requested alternative credit amounts. This includes credits for
stop-start systems, high-efficiency lighting, infrared glass glazing, solar reflective paint, and
active seat ventilation technologies. EPA is no longer accepting retroactive credit claims.
High Efficiency Air Conditioning Compressors
In September of 2015, EPA approved credits for the use of high efficiency air conditioner
compressors. These systems provide real-world benefits using an A/C compressor with
variable crankcase suction valve technology.
High Efficiency Alternators
In December of 2016, EPA approved credits for the use of high efficiency alternators. High
efficiency alternators use new technologies that reduce the overall load on the engine
while continuing to meet the electrical demands of the vehicle systems, resulting in lower
fuel consumption and lower CO2 emissions. High efficiency alternators were added to the
off-cycle menu credits beginning in model year 2020, although some manufacturers
continue to receive credits through alternative methodology instead.
Active Climate Controlled Seats
In September of 2017, EPA approved credits for the use of active climate-controlled seats,
which provide cooled air directly to the occupants through the seats, thus reducing the
overall load on the air conditioning system.
Brushless Motors
In October of 2019, EPA approved credits for the use of a pulse width modulated brushless
motor power controller through the alternative methodology pathway. This "brushless
motor" technology is used to improve the efficiency of the HVAC system.
Cold Storage Evaporators
In October of 2020, EPA approved credits for a "cold storage evaporator." Air-conditioning
systems employing this technology essentially freeze a mass of material during normal
operation, such that the material can provide cabin cooling when the engine is off. This
allows stop-start systems to leave the engine off longer, resulting in reductions in
emissions and fuel usage.
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Summary of Off-Cycle Alternative Methodology Credits
Since the beginning of the light-duty GHG program, twelve manufacturers have been
granted approval for alternative methodology off-cycle GHG credits using the alternative
methodology pathway. Eight manufacturers requested off-cycle credits based on the
approved alternative methodologies in model year 2023. Table 5.4 shows the impact of the
credits submitted for model year 2023. On a total fleetwide basis, the aggregated credit is
0.4 g/mi for model year 2023.
Table 5.4. Model Year 2023 Off-Cycle Technology Credits from an Alternative
Methodology, by Manufacturer and Technology (g/mi)
Active
Cold
Total
Menu
A/C
High-
Climate
Storage
Alt.
Tech-
Com-
Efficiency
Control
Brushless
Evap-
Method
Manufacturer
nologies
pressor
Alternator
Seats
Motors
orator
Credits
GM
-
-
-
-
0.1
-
0.1
Honda
-
-
-
-
-
0.7
0.7
Hyundai
0.0
0.8
-
-
-
-
0.8
Jaguar Land
-
-
0.8
-
-
-
0.8
Rover
Kia
-
0.5
-
-
-
-
0.5
Mazda
0.9
-
-
-
-
-
0.9
Mitsubishi
0.7
-
-
-
-
-
0.7
Nissan
-
0.1
-
-
-
-
0.1
Stellantis
-
-
0.4
-
-
-
0.4
Subaru
-
-
-
-
0.0
-
0.0
Toyota
-
0.1
0.0
0.1
0.1
0.6
0.9
All
0.0
0.1
0.0
0.0
0.0
0.1
0.4
Manufacturers
Off-Cycle Performance Credit Summary
In total, the industry achieved 8.6 g/mi of off-cycle performance credits in model year 2023.
More than 95% of those credits were claimed using technologies, and credit definitions, on
the off-cycle menu. The remaining credits were due almost entirely to manufacturer
submitted alternative methodologies. Figure 5.10 shows the average credit, in g/mi, that
each manufacturer achieved in model year 2023. Fisker achieved the highest gram per mile
benefit from off-cycle credits at 13.9 g/mi, followed closely by multiple manufacturers
around 10-11 g/mi. All manufacturers that qualified for the GHG Program reported at least
some off-cycle credits for model year 2023.
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Figure 5.10. Total Off-Cycle Credits by Manufacturer for Model Year 2023
14-
12-
10-
£
jra 8 -
T3
-------
as part of their GHG reporting. Hence, this GHG compliance report does not include
information from manufacturers using this option.
The second option for manufacturers is to include CH4 and N2O, on a C02-equivalent basis,
when calculating their fleet average performance values, in lieu of demonstrating
compliance with the regulatory caps. This method directly accounts for CH4 and N2O,
increasing the performance value of a manufacturer's fleets, while the standards remain
unchanged. Analyses of emissions data have shown that use of this option may add
approximately 3 g/mi to a manufacturer's fleet average. No manufacturers have elected to
use this approach since the 2019 model year.
The third option for complying with the CH4 and N2O standards allows manufacturers to
propose an alternative, less stringent CH4 and/or N2O standard for any vehicle that may
have difficulty meeting the specific standards. However, manufacturers that use this
approach must also calculate the increased emissions due to the less stringent standards
and the production volumes of the vehicles to which those standards apply, and then add
that impact from their overall fleet performance. Ten manufacturers made use of the
flexibility offered by this approach in the 2023 model year. In aggregate, the impact of the
methane and nitrous oxide flexibilities resulted in an increase in the industry-wide
performance of about 0.2 g/mi.
Summary of Manufacturer Performance
Each of the performance credits and adjustments described here have been used by
manufacturers as part of their compliance strategies under the GHG program. As
described above, the availability of these provisions, and the magnitude of their impact,
has varied both by manufacturer and model year. Table 5.5 through Table 5.10 below
detail the impact of these provisions by manufacturer for model year 2023, and for the
aggregated industry over the course of the GHG Program. The performance values in these
tables can be derived by subtracting the credits and adjustment from the 2-Cycle Tailpipe
value.
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Table 5.5. Manufacturer Performance in Model Year 2023, All (g/mi)
Performance Credits and Adjustments
2-Cycle
Adv.
Off-
ch4&
Performance
Manufacturer
Tailpipe
Tech
FFV
A/C
Cycle
n2o
Value
Aston Martin
394
-
-
15.6
2.9
-
375
BMW
236
4.7
-
21.7
10.0
-0.0
200
Ferrari
390
-
-
13.8
1.3
-
375
Fisker
0
10.0
-
17.6
13.9
-
-42
Ford
290
7.8
-
23.9
11.2
-0.2
248
GM
307
2.9
-
22.9
10.8
-0.5
271
Honda
242
-
-
20.3
9.4
-
212
Hyundai
228
6.0
-
19.3
7.7
-0.0
195
Jaguar Land Rover
338
0.5
-
24.1
10.5
-
303
Kia
227
3.7
-
19.2
7.1
-0.0
197
Lucid
0
10.0
-
18.8
4.9
-
-34
Mazda
250
0.0
-
22.0
6.5
-0.6
222
McLaren
291
-
-
12.0
3.9
-
275
Mercedes
242
10.0
-
14.6
5.2
-
212
Mitsubishi
224
3.3
-
22.1
3.0
-
196
Nissan
232
2.5
-
20.3
6.6
-
203
Rivian
0
10.0
-
23.4
3.6
-
-37
Stellantis
315
2.7
-
23.4
9.9
-0.2
279
Subaru
240
2.4
-
20.9
4.7
-0.0
212
Tesla
0
10.0
-
17.5
4.9
-
-32
Toyota
248
1.8
-
20.6
7.9
-0.3
218
Volkswagen
249
10.0
-
20.8
9.6
-0.0
209
Volvo
192
10.0
-
21.9
10.7
-
150
All Manufacturers
249
4.1
-
21.2
8.6
-0.2
215
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Table 5.6. Industry Performance by Model Year, All (g/mi)
Performance Credits and Adjustments
2-Cycle
Adv.
Off-
ch4&
Performance
Model Year
Tailpipe
Tech
FFV
A/C
Cycle
n2o
Value
2012
302
-
8.1
6.1
1.0
-0.2
287
2013
294
-
7.8
6.9
1.1
-0.3
278
2014
294
-
8.9
8.5
3.3
-0.2
273
2015
286
-
6.4
9.4
3.4
-0.2
267
2016
285
-
-
10.3
3.6
-0.1
271
2017
284
2.2
-
13.8
5.6
-0.2
262
2018
280
3.7
-
16.3
7.1
-0.1
253
2019
282
3.0
-
17.9
7.7
-0.1
253
2020
275
2.9
-
19.3
8.4
-0.2
244
2021
272
3.8
-
20.8
8.7
-0.3
239
2022
263
-
-
21.1
9.2
-0.2
233
2023
249
4.1
-
21.2
8.6
-0.2
215
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Table 5.7. Manufacturer Performance in Model Year 2023, Car (g/mi)
Performance Credits and Adjustments
2-Cycle
Adv.
Off-
ch4&
Performance
Manufacturer
Tailpipe
Tech
FFV
A/C
Cycle
n2o
Value
Aston Martin
364
-
-
13.8
2.9
-
347
BMW
212
-
-
18.7
6.7
-0.1
187
Ferrari
390
-
-
13.8
1.3
-
375
Fisker
-
10.0
-
17.6
13.9
-
-42
Ford
132
42.4
-
18.8
5.6
-0.0
65
GM
211
12.5
-
18.4
5.9
-
174
Honda
199
-
-
16.7
6.2
-
176
Hyundai
196
9.8
-
17.3
4.9
-0.1
164
Jaguar Land Rover
342
-
-
18.7
4.9
-
318
Kia
197
5.8
-
17.2
3.7
-0.1
170
Lucid
-
10.0
-
18.8
4.9
-
-34
Mazda
221
0.2
-
17.7
3.5
-0.4
200
McLaren
291
-
-
12.0
3.9
-
275
Mercedes
192
10.0
-
13.3
4.7
-
164
Mitsubishi
167
-
-
18.1
0.3
-
149
Nissan
197
4.8
-
17.8
4.3
-
170
Rivian
-
-
-
-
-
-
-
Stellantis
347
-
-
18.8
2.3
-0.1
326
Subaru
251
-
-
15.4
0.9
-0.1
235
Tesla
-
10.0
-
16.8
4.7
-
-32
Toyota
199
1.0
-
17.6
4.1
-0.0
176
Volkswagen
213
10.0
-
17.1
6.5
-0.0
179
Volvo
80
15.4
-
17.6
5.7
-
41
All Manufacturers
176
7.0
-
17.4
4.8
-0.0
147
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Table 5.8. Industry Performance by Model Year, Car (g/mi)
Performance Credits and Adjustments
2-Cycle
Adv.
Off-
ch4&
Performance
Model Year
Tailpipe
Tech
FFV
A/C
Cycle
n2o
Value
2012
259
-
4.0
5.4
0.6
-0.1
249
2013
251
-
4.0
6.3
0.7
-0.3
240
2014
250
-
4.6
7.5
2.2
-0.3
236
2015
243
-
3.1
8.1
2.3
-0.1
230
2016
240
-
-
8.8
2.3
-0.1
229
2017
235
4.3
-
10.2
3.5
0.0
217
2018
228
7.6
-
12.9
4.2
0.0
204
2019
228
6.3
-
14.7
4.5
0.0
203
2020
221
6.5
-
15.8
5.2
-0.1
194
2021
210
8.5
-
17.0
5.3
0.0
179
2022
197
-
-
17.3
6.0
0.0
174
2023
176
7.0
-
17.4
4.8
0.0
147
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Table 5.9. Manufacturer Performance in Model Year 2023, Truck (g/mi)
Manufacturer
2-Cycle
Tailpipe
Performance Credits and Adjustments
Performance
Value
Adv.
Tech
FFV
A/C
Off-
Cycle
ch4&
n2o
Aston Martin
421
-
-
17.2
2.9
-
401
BMW
258
9.0
-
24.4
13.0
(0.0)
212
Ferrari
-
-
-
-
-
-
-
Fisker
-
-
-
-
-
-
-
Ford
305
4.6
-
24.4
11.7
(0.2)
264
GM
336
-
-
24.3
12.2
(0.6)
300
Honda
278
-
-
23.3
12.2
-
243
Hyundai
271
0.9
-
22.1
11.5
-
237
Jaguar Land Rover
338
0.5
-
24.2
10.6
-
303
Kia
258
1.4
-
21.4
10.7
-
224
Lucid
-
-
-
-
-
-
-
Mazda
253
-
-
22.4
6.9
(0.7)
224
McLaren
-
-
-
-
-
-
-
Mercedes
286
10.0
-
15.8
5.7
-
254
Mitsubishi
232
3.8
-
22.6
3.4
-
202
Nissan
269
-
-
22.8
9.0
-
237
Rivian
-
10.0
-
23.4
3.6
-
(37)
Stellantis
310
3.1
-
24.1
11.1
(0.2)
272
Subaru
239
2.8
-
21.7
5.3
-
209
Tesla
-
10.0
-
23.8
6.9
-
(41)
Toyota
274
2.1
-
22.1
10.0
(0.4)
240
Volkswagen
269
10.0
-
22.8
11.3
(0.0)
225
Volvo
240
7.7
-
23.7
12.8
-
196
All Manufacturers
287
2.6
-
23.2
10.6
(0.2)
251
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Table 5.10. Industry Performance by Model Year, Truck (g/mi)
Performance Credits and Adjustments
2-Cycle
Adv.
Off-
ch4&
Performance
Model Year
Tailpipe
Tech
FFV
A/C
Cycle
n2o
Value
2012
369
-
14.5
7.3
1.6
-0.3
346
2013
360
-
13.8
7.9
1.7
-0.3
337
2014
349
-
14.3
9.7
4.6
-0.1
321
2015
336
-
10.3
11.0
4.6
-0.2
310
2016
332
-
-
11.8
5.1
-0.2
315
2017
330
0.2
-
17.3
7.7
-0.3
305
2018
320
0.6
-
19.0
9.3
-0.2
292
2019
318
0.7
-
20.1
9.9
-0.1
288
2020
311
0.5
-
21.6
10.6
-0.3
279
2021
304
1.4
-
22.7
10.4
-0.5
270
2022
297
-
-
23.1
10.8
-0.3
263
2023
287
2.6
-
23.2
10.6
-0.2
251
~
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C. GHG Program Credits and Deficits
The previous two sections outlined how to determine manufacturer standards and
manufacturer performance values for the current model year. The next step in the
compliance process it to compare the car and truck standards to the corresponding
performance values to determine if each fleet was above or below the standards. This
process then allows manufacturers to determine if each fleet will create GHG program
credits or deficits. These program credits are the credits available to manufacturers to
bank, trade, and ultimately show compliance with the overall GHG program.
Program credits are always expressed as mass-based credits in megagrams of CO2. A mass-
based credit metric captures the performance of each manufacturer's fleets relative to the
standards, the total number of vehicles produced in each fleet, and the expected lifetime
vehicle miles travelled for those vehicles. This conversion is necessary to enable the
banking and trading of credits across manufacturer fleets, model years, and between
manufacturers. To convert g/mi emission rates to total emission reductions in Mg, see the
insert "How to Calculate Total Emissions from an Emission Rate" at the beginning of this
section.
Manufacturers also had a limited, and voluntary, option to generate program credits in
model years 2009 through 2011 from early technology adoption before the standards went
into effect. Credit expirations, credit forfeitures, and credit trades between manufacturers,
are also important in determining the overall program credits available to manufacturers.
This section will detail these components of the GHG program, which are essential in
determining manufacturer overall credit balances and manufacturer compliance with the
GHG program.
Generating Credits and Deficits from Model Year Performance
Manufacturers can calculate the credits or deficits created within a model year by
comparing their car and truck fleet standards to their respective performance values and
converting from a gram per mile emission rate to a mass-based total. When a car or truck
fleet is below the applicable standard, that fleet generates credits for the manufacturer.
Conversely, when a car or truck fleet is above the applicable standard, that fleet generates
deficits.
The GHG program evaluates car and truck fleets separately, which means that there is no
single, overall standard for manufacturers. However, it is possible to calculate an effective
a J 127
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overall manufacturer standard, and performance value, from the underlying passenger car
and truck data. Figure 5.11 illustrates the performance of all manufacturers in model year
2023, compared to their effective overall standards.
Of the 23 manufacturers that produced vehicles in model year 2023, eight were below their
overall effective standards, and generated net credits (accounting for credits and deficits
from each manufacturer's car and truck fleets). Fifteen manufacturers were above their
standards and generated net deficits in model year 2023. The fact that manufacturers were
above their standards in Figure 5.11 does not mean that these manufacturers were out of
compliance with the GHG program, as discussed later in this report.
Figure 5.11. Performance and Standards by Manufacturer, Model Year 2023
Jaguar Land Rover-
Stellantis
GM -
Mazda -
Subaru -
Honda -
Toyota -
Nissan -
Volkswagen -
Kia -
Hyundai -
Mercedes -
Mitsubishi
Ferrari -
Ford-
BMW-
Aston Martin -
McLaren -
Volvo -
Tesla -
Lucid -
Fisker-
Rivian -
0 100 200 300 400
Compliance GHG (g/mi)
Above
Standard
Below
Standard
303
1199^209
1190^197
1190^195
[207^212
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In model year 2023, four manufacturers generated credits from their truck fleets, while
fifteen generated deficits. Nine manufacturers generated credits with their car fleets,
compared to 13 that generated deficits.25 Table 5.11 through Table 5.16 provide a
summary of the standards, manufacturer performance, and the credits and deficits
generated by each manufacturer's car and truck fleets for model year 2023 and for the
aggregated industry for model years 2009-2023 (including early credits). These tables show
only credits generated within a model year, and do not account for credits used to offset
deficits in other model years, credits that are traded between manufacturers, or credits
that have expired or been forfeited - all of which will be discussed later in this section. The
tables showing combined car and truck, or overall industry values, are aggregated from the
underlying car and truck data.
25 Not all manufacturers have both a car and truck fleet. Four manufacturers (Ferrari, Fisker, Lucid, and
McLaren) did not produce trucks in model year 2023, and one (Rivian) did not produce cars.
a
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Table 5.11. Credits Earned by Manufacturers in Model Year 2023, All
Performance
Standard
Credits
Value
Standard
Exceedance
Generated
Manufacturer
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Aston Martin
375
376
-1
2,417
397
BMW
200
200
-1
349,611
37,895
Ferrari
375
373
2
3,413
-1,289
Fisker
-42
191
-233
6,895
313,070
Ford
248
246
1
1,540,119
-406,987
GM
271
232
38
2,132,177
-17,767,927
Honda
212
198
14
1,003,728
-2,877,872
Hyundai
195
190
5
990,102
-1,031,926
Jaguar Land Rover
303
230
73
97,472
-1,602,600
Kia
197
190
7
893,905
-1,287,359
Lucid
-34
189
-223
6,745
293,307
Mazda
222
201
21
341,605
-1,628,396
McLaren
275
329
-54
1,159
12,188
Mercedes
212
207
5
302,914
-306,509
Mitsubishi
196
194
2
89,507
-45,058
Nissan
203
191
11
998,235
-2,385,123
Rivian
-37
255
-292
39,151
2,582,415
Stellantis
279
236
43
1,201,130
-11,538,248
Subaru
212
197
15
519,743
-1,764,790
Tesla
-32
184
-217
789,720
33,896,698
Toyota
218
206
12
2,158,030
-5,457,268
Volkswagen
209
199
10
605,163
-1,244,913
Volvo
150
206
-57
123,459
1,512,529
All Manufacturers
215
212
4
14,196,400
-10,697,766
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Table 5.12. Total Credits Earned by Model Year, All
Performance
Standard
Credits
Model
Value
Standard
Exceedance
Generated
Credit
Year
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Expiration
2009
98,522,058
2014
2010
96,891,340
2021
2011
38,770,273
2021
2012
287
299
-12
13,446,550
33,033,097
2021
2013
278
292
-14
15,200,118
42,234,774
2021
2014
273
287
-13
15,514,338
43,292,494
2021
2015
267
274
-7
16,740,264
25,218,704
2021
2016
271
263
8
16,279,911
-27,615,344
2021
2017
262
258
4
17,015,504
-15,370,662
2023
2018
253
252
1
16,259,539
-3,204,647
2024
2019
253
246
7
16,139,407
-23,247,116
2024
2020
244
239
6
13,720,942
-17,093,797
2025
2021
239
238
1
13,811,848
-2,738,562
2026
2022
233
234
-1
12,859,584
3,025,361
2027
2023
215
212
4
14,196,400
-10,697,766
2028
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Table 5.13. Credits Earned by Manufacturers in Model Year 2023, Car
Performance
Standard
Credits
Value
Standard
Exceedance
Generated
Manufacturer
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Aston Martin
347
376
-29
1,245
6,988
BMW
187
173
14
179,271
-478,511
Ferrari
375
373
2
3,413
-1,289
Fisker
-42
191
-233
6,895
313,070
Ford
65
175
-110
149,284
3,197,512
GM
174
165
9
556,762
-1,002,694
Honda
176
167
9
500,159
-882,174
Hyundai
164
169
-5
603,283
587,022
Jaguar Land Rover
318
165
153
1,818
-54,455
Kia
170
164
6
493,781
-612,459
Lucid
-34
189
-223
6,745
293,307
Mazda
200
160
40
38,579
-301,443
McLaren
275
329
-54
1,159
12,188
Mercedes
164
179
-15
153,791
450,218
Mitsubishi
149
146
3
11,903
-6,093
Nissan
170
165
5
547,817
-530,386
Rivian
-
-
-
-
-
Stellantis
326
188
138
182,429
-4,914,868
Subaru
235
160
75
69,987
-1,022,583
Tesla
-32
180
-212
719,920
29,740,011
Toyota
176
167
9
820,732
-1,492,386
Volkswagen
179
165
14
236,582
-665,238
Volvo
41
170
-129
40,710
1,022,704
All Manufacturers
147
170
-23
5,326,265
23,658,441
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Table 5.14. Total Credits Earned by Model Year, Car
Performance
Standard
Credits
Model
Value
Standard
Exceedance
Generated
Credit
Year
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Expiration
2009
58,018,752
2014
2010
50,856,700
2021
2011
8,831,637
2021
2012
249
267
-18
8,657,393
30,484,967
2021
2013
240
261
-21
9,747,624
39,249,608
2021
2014
236
253
-17
9,209,352
30,407,996
2021
2015
230
241
-12
9,602,215
22,043,043
2021
2016
229
231
-2
9,012,178
3,411,251
2021
2017
217
219
-2
8,954,269
2,999,670
2023
2018
204
209
-6
7,800,403
8,647,205
2024
2019
203
198
4
7,170,630
-5,822,099
2024
2020
194
189
4
6,029,845
-5,025,051
2025
2021
179
185
-6
5,119,934
5,974,761
2026
2022
174
183
-9
4,748,244
8,702,083
2027
2023
147
170
-23
5,326,265
23,658,441
2028
C\,
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Table 5.15. Credits Earned by Manufacturers in Model Year 2023, Truck
Performance
Standard
Credits
Value
Standard
Exceedance
Generated
Manufacturer
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Aston Martin
401
376
25
1,172
-6,591
BMW
212
225
-13
170,340
516,406
Ferrari
-
-
-
-
-
Fisker
-
-
-
-
-
Ford
264
253
11
1,390,835
-3,604,499
GM
300
253
47
1,575,415
-16,765,233
Honda
243
225
18
503,569
-1,995,698
Hyundai
237
218
19
386,819
-1,618,948
Jaguar Land Rover
303
231
72
95,654
-1,548,145
Kia
224
217
7
400,124
-674,900
Lucid
-
-
-
-
-
Mazda
224
205
19
303,026
-1,326,953
McLaren
-
-
-
-
-
Mercedes
254
232
22
149,123
-756,727
Mitsubishi
202
200
2
77,604
-38,965
Nissan
237
219
18
450,418
-1,854,737
Rivian
-37
255
-292
39,151
2,582,415
Stellantis
272
243
29
1,018,701
-6,623,380
Subaru
209
202
7
449,756
-742,207
Tesla
-41
223
-264
69,800
4,156,687
Toyota
240
227
13
1,337,298
-3,964,882
Volkswagen
225
218
7
368,581
-579,675
Volvo
196
222
-26
82,749
489,825
All Manufacturers
251
234
17
8,870,135
-34,356,207
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Table 5.16. Total Credits Earned by Model Year, Truck
Performance
Standard
Credits
Model
Value
Standard
Exceedance
Generated
Credit
Year
(g/mi)
(g/mi)
(g/mi)
Production
(Mg)
Expiration
2009
40,503,306
2014
2010
46,034,640
2021
2011
29,938,636
2021
2012
346
349
-2
4,789,157
2,548,130
2021
2013
337
339
-3
5,452,494
2,985,166
2021
2014
321
330
-9
6,304,986
12,884,498
2021
2015
310
312
-2
7,138,049
3,175,661
2021
2016
315
297
19
7,267,733
-31,026,595
2021
2017
305
295
10
8,061,235
-18,370,332
2023
2018
292
286
6
8,459,136
-11,851,852
2024
2019
288
279
9
8,968,777
-17,425,017
2024
2020
279
272
7
7,691,097
-12,068,746
2025
2021
270
265
4
8,691,914
-8,713,323
2026
2022
263
260
3
8,111,340
-5,676,722
2027
2023
251
234
17
8,870,135
-34,356,207
2028
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Program Credits for Early Adoption of Technology
The GHG program included an optional provision that allowed manufacturers to generate
credits in the 2009-2011 model years, prior to the implementation of regulatory standards
in model year 2012. This flexibility allowed manufacturers to generate credits for achieving
tailpipe CO2 emissions targets or introducing emission-reducing technology before model
year 2012. Sixteen manufacturers participated in the early credits program, generating a
large bank of credits for the industry before the standards took effect in model year 2012.
The pathways for earning credits under the early credit program mirrored those built into
the annual GHG requirements, including improved tailpipe CO2 performance and A/C
systems, off-cycle credits for other technologies that reduced CO2 emissions, and credits
for manufacturing electric, plug-in hybrid, and fuel cell vehicles.
Of the 234 Teragrams (Tg)26 of early credits, 85% of those credits were generated from
performing better than the tailpipe CO2 emissions targets established in the regulations. To
earn credits based on tailpipe CO2 performance, manufacturers could demonstrate tailpipe
emissions levels below either California or national standards, dependent on the state the
car was sold in. California developed GHG standards prior to the adoption of the EPA GHG
program, and some states had adopted these standards. In all other states, C02 levels were
calculated based on the national CAFE standards. Of the remaining early credits, about 10%
were created through improving A/C system leakage, 4% were due to A/C efficiency
improvements, and just over 1 % were due to off-cycle credits for other technologies.
The model year 2009 credits could not be traded between companies and were limited to a
5-year credit life. Thus, all credits earned in model year 2009, or about a third of the early
credits generated, expired at the end of the 2014 model year if not already used. The
remaining 2010-2011 model year credits were banked and were usable through the 2021
model year. After model year 2021 any remaining unused model year 2010 or 2011 credits
expired. Manufacturers can no longer generate early credits. The distribution of early
credits earned by manufacturer is shown in Figure 5.12. More details of the early credit
program can be found in the "Early Credits Report," which was released by EPA in 2013.27
261 Teragram = 1 million Megagrams.
27 Greenhouse Gas Emission Standards for Light-Duty Automobiles: Status of Early Credit Program for Model
Years 2009-2011, Compliance Division, Office of Transportation and Air Quality, U.S. Environmental Protection
Agency, Report No. EPA-420-R-13-005, March 2013.
a
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Figure 5.12. Early Credits by Manufacturer
o
o
M
O
D)
"O
to
LU
CD
1
CD
80-
60'
40-
20
0-
Model Year
¦ 2011
2010
¦ 2009
I
fjtj' MS y/////
Expiration and Forfeiture of Credits
All credits earned within the GHG program have expiration dates, based on the model year
in which they were earned. Any credits held by any manufacturer past their expiration date
will be considered expired, and will not be available to offset future deficits, to sell to other
manufacturers, or usable in any other way. Credits earned in model year 2009 under the
early credit program were the first to expire, at the end of model year 2014. At that point,
69 Tg of credits expired.
At the end of model year 2021, all unused credits from model years 2010 to 2016 expired.
These expiring credits totaled 39 Tg. At the end of model year 2023, all unused credits from
model years 2017 expired, which totaled another 0.5 Tg. The remaining credits that
currently exist, or are generated in future years, will expire according to the schedule
defined by the GHG Program, and shown in Table 5.17.
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Table 5.17 Credit Expiration Schedule
Credits earned in
model year:
Expire at the end of
model year:
2017
2018
2019
2023
2024
2024
2020 and later
credits last 5 years
A limited number of credits have been forfeited by several manufacturers. Although
forfeiture and expiration both have fundamentally the same effect - a loss or removal of
credits - forfeiture is considered a different and less common mechanism, brought about
by unique circumstances. Hyundai and Kia forfeited a specified quantity of 2013 model
year credits after an investigation into their testing methods that concluded with a
settlement announced on November 3, 2014.
VW similarly forfeited some credits, deducted from their 2017 model year balance. In the
course of the investigation concerning defeat devices in VW's diesel vehicles, the EPA
discovered that the company employed software to manage vehicle transmissions in
gasoline vehicles. This software causes the transmission to shift gears during the EPA-
prescribed emissions test in a manner that sometimes optimizes fuel economy and
greenhouse gas (GHG emissions during the test, but not under normal driving conditions.
This resulted in inflated fuel economy values for some vehicles. VW forfeited credits to
account for the higher CO2 emissions of these vehicles in actual use.
Pursuant to a resolution with General Motors regarding in-use verification program ("IUVP")
testing results for carbon-related exhaust emissions ("CREE") on GM vehicles originally
certified with EPA before EPA's implementation of drive-cycle metric regulatory
requirements, GM agreed to voluntarily recalculate its GHG credit balance by retiring
49,067,347 Mg of GM's GHG credits. GM recalculated its GHG credit balances and
submitted the updated results in GM's most recently filed GHG report. Those adjustments
are reflected in this report.
Additional manufacturers forfeited credits because of their participation in the Temporary
Lead Time Alternative Allowance Standards (TLAAS). Opting into these less stringent
standards, which are no longer available, came with some restrictions, including the
requirement that any credits accumulated by using the TLAAS standards may not be used
by or transferred to a fleet meeting the primary standard. This impacted Porsche, which
was bought by VW in 2012. Porsche held some credits earned against the TLAAS standards
0
138
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at the time they were merged with VW, and VW was not participating in the TLAAS
program. Thus, those credits could not carry over to the merged company and were lost.
Similarly, Mercedes and Volvo reached the end of the TLAAS program, which applied
through the 2015 model year, with credits in their TLAAS bank that could not be
transferred to their post-2015 bank and thus were forfeited.
Credit Transactions
Credit trading among manufacturers has been an important part of the program for many
manufacturers. An active credit market is enabling manufacturers to purchase credits to
demonstrate compliance, with fifteen manufacturers selling credits, twenty manufacturers
purchasing credits, and more than 140 credit transactions occurring since the inception of
the program. Twenty-six total manufacturers have made credit transactions, with nine
manufacturers both selling and buying credits. Credits may be traded among
manufacturers with a great deal of flexibility, however there are several limitations,
including:
1) Manufacturers must offset any existing deficits before selling credits.
2) Manufacturers may not sell credits they do not have.
3) Manufacturers are the only parties that may engage in credit transactions and hold
credits (although a third party may facilitate transactions.
4) Manufacturers may not sell early credits created in model year 2009.
5) Manufacturers may not sell credits generated under an alternative standard
(including TLAAS and small volume manufacturer standards.
As of October 1, 2024, about 270 Tg of credits have been traded between manufacturers.
Figure 5.13 shows the total quantity of credits that have been bought or sold by
manufacturers since the beginning of the GHG program. Credits that have been sold are
shown as negative credits, since the sale of credits will reduce the selling manufacturer's
credit balance. Conversely, credits that have been purchased are shown as positive credits,
since they will increase the purchasing manufacturer's credit balance.
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Manufacturers can purchase or sell credits generated in any model year. The model year
the credits were generated in remains important, as those credits must be used, and will
expire, according to the model year in which they were originally created. Figure 5.13 also
shows the distribution of credits sold and acquired by the model year after which the
credits will expire. One additional credit transaction occurred in 2021, as Volvo used
banked credits to offset the small deficit Lotus held prior to their merger into one
manufacturer under the GHG program.
Figure 5.13. Total Credits Transactions
Sold Purchased
O
100-
80-
60-
Credits
| Expiring 2028
Expiring 2027
Expiring 2026
Expiring 2025
Expiring 2024
Expired 2023
Expired 2021
O 40-I
o
O)
20-
0-
-20-
-40-
-60-
-80-
-100-
-120-
-i
^ ^ J?J? j?
- .HI
$
cF
^ J? cf if <# #
^ N ^ V
#
#"
~
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D. GHG Program Credit Balances
The final GHG program credit balance at the end of each model year, and compliance
status, for each manufacturer relies on all the components outlined to this point in the
report. Manufacturer car and truck standards and performance within each model year,
early credits, credit trades, credit forfeitures, and credit expirations are all required to
determine final model year credit balances for each manufacturer. If a manufacturer ends
the model year with a positive credit balance, they are in compliance with the GHG
program, and the accrued credits will be carried forward to the next model year.
Manufacturers that end any model year with a deficit have up to three years to offset all
deficits to avoid non-compliance and may not report deficits for more than 3 years in a
row. In addition, manufacturers may not carry forward any credits unless all deficits have
been offset.
If a manufacturer generates a deficit from either their car or truck fleets, that deficit must
be offset from existing credits, if they are available. When applying credits, the oldest
available credits are applied to the current deficit by default. Credits earned in past model
years may be applied to car or truck deficits, regardless of how they were generated. Table
5.18 shows a simple example. In this case, a manufacturer generated 300,000 Mg of credits
from its car fleets in model years 2021, 2022, and 2023. The manufacturer's truck fleets did
not generate any credits or deficits in model years 2021 or 2022 but generated a deficit of
500,000 Mg in 2023. Because the oldest credits are applied first, credits generated in model
year 2021 are the first credits applied towards the 2023 truck deficit, then 2022 and 2023
credits would be applied until the deficit is offset. After offsetting the example truck deficit
in Table 5.18, this manufacturer would be left with 100,000 Mg of credits from model year
2022, and 300,000 Mg of credits from model year 2023 to bank for future use.
Table 5.18. Example of a Deficit Offset with Credits from Previous Model Years
Using Credits to Offset Deficits
Generated Truck Credits
Generated Car Credits
Model Model Model
Year 2021 Year 2022 Year 2023
0 0 -500,000
300,000 300,000 300,000
Applied to 2023 Deficits
-300,000 -200,000
Remaining Credits
0 100,000 300,000
13
141
-------
The complete credit and deficit accounting for each manufacturer also includes the impact
of credits earned as part of the early credit program, credit trades, credit forfeitures, and
credit expirations over the full span of the GHG program. The detailed deficit offset
calculations for each manufacturer are not published in this report, since some of the
credit trade information is considered confidential business information and is not
published in detail by EPA. However, most of the underlying data for all manufacturers and
model years is available on the Automotive Trends website at
https://www.epa.gov/automotive-trends.
Compliance Status After the 2023 Model Year
EPA determines the compliance status of each manufacturer based on their credit balance
at the end of the model year, after offsetting all deficits. Because credits may not be carried
forward unless deficits from all prior model years have been resolved, a positive credit
balance means compliance with the current and all previous model years of the program. If
a manufacturer ends the model year with any deficits, that manufacturer must offset the
deficit within three years to avoid non-compliance. For model year 2023, deficits from
model year 2020 or prior would be considered non-compliant.
Figure 5.14 shows the credit balance of all manufacturers after model year 2023 including
the breakdown of expiration dates, and the distribution of deficits, by age of the deficit. All
but three manufacturers ended the 2023 model year with a positive credit balance and are
thus in compliance with model year 2023 and all previous years of the GHG program.
Volkswagen and Mazda ended model year 2023 with a deficit and must offset their deficits
by the model year 2026 reporting period to remain in compliance. Kia ended model year
2023 with a deficit, which is their third straight model year reporting a deficit. Kia must
offset all deficits by the model year 2024 reporting period to remain in compliance.
The breakdown of each manufacturer's final model year 2023 credit balance, based on the
source of the credits or deficits, is shown in Table 5.19. Each manufacturer has pursued a
unique combination of early credits generated in model years 2009-2011, credits or deficits
created in model years 2012-2023, and credit expirations, forfeitures, and trades to
achieve their current credit balance. The "net" credits earned in Table 5.19 are a sum of all
credits and deficits earned by a manufacturer and may not be the sum of credits remaining
due to the use of banked credits across model years. The actual distribution of credits, by
expiration date, and deficits, by the age of the deficit, are shown in Table 5.20.
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Figure 5.14. Manufacturer Credit Balance After Model Year 2023
Honda -
Stellantis-
Toyota-
Subaru-
Ford-
GM-
Nissan-
Volvo -
Mercedes-
Hyundai -
Rivian-
BMW-
Mitsubishi
Fisker-
Tesla-
Jaguar Land Rover-
Aston Martin -
McLaren -
Ferrari -
Lucid -
BYD Motors -
Mazda-
Volkswagen -
Kia-
¦
~r
0
| Credits
Credits
Credits
Credits
Credits
Deficits
Deficits
Expiring 2028
Expiring 2027
Expiring 2026
Expiring 2025
Expiring 2024
from 2023
from 2022
-r~
10
"T"
20
"T"
30
GHG Credits (Tg of CCL)
143
-------
Table 5.19. Final Credit Balance by Manufacturer for Model Year 2023 (Mg)
Manufacturer
Early Credits
Earned
2009-2011
Net Credits
Earned
2012-2021
Net Credits
Earned
2023
Credits
Expired
Credits
Forfeited
Credits
Purchased
or Sold
Final 2023
Credit
Balance
Aston Martin
3,332
-16,262
397
-
-
75,844
63,311
BMW
1,251,522
-2,939,278
37,895
-135,125
-
3,719,709
1,934,723
BYD Motors
-
5,568
-
-5,400
-
-
168
Coda
-
7,251
-
-
-
-7,251
-
Ferrari
-
-179,094
-1,289
-80,667
-
268,700
7,650
Fisker
-
-
313,070
-
-
-
313,070
Ford
16,116,453
1,526,263
-406,987
-12,552,071
-
4,254,634
8,938,292
GM
25,788,547
-34,850,134
-17,767,927
-11,558
-49,067,347
82,161,795
6,253,376
Honda
35,842,334
65,991,437
-2,877,872
-15,872,556
-
-48,950,245
34,133,098
Hyundai
14,007,495
-1,883,691
-1,031,926
-4,579,410
-169,775
-2,871,951
3,470,742
Jaguar Land Rover
-
-4,219,278
-1,602,600
-10,128
-
6,055,028
223,022
Karma
-
84,597
-
-56,011
-
-28,586
-
Kia
10,444,192
-8,309,552
-1,287,359
-2,362,882
-123,956
235,000
-1,404,557
Lotus
-
-3,147
-
-
-
3,147
-
Lucid
-
158,161
293,307
-
-
-451,161
307
Mazda
5,482,642
1,100,402
-1,628,396
-5,097,987
-
-32,199
-175,538
McLaren
-
-45,769
12,188
-
-
45,769
12,188
Mercedes
378,272
-21,264,100
-306,509
-
-28,416
24,927,713
3,706,960
Mitsubishi
1,449,336
1,060,174
-45,058
-1,135,814
-
157,119
1,485,757
Nissan
18,131,200
6,084,234
-2,385,123
-12,695,612
-
-5,098,348
4,036,351
Porsche
-
426,439
-
-
-426,439
-
-
Rivian
-
1,385,539
2,582,415
-
-
-1,367,801
2,600,153
Stellantis
10,827,083
-75,475,341
-11,538,248
-
-
102,569,367
26,382,861
Subaru
5,755,171
19,430,268
-1,764,790
-917,606
-
-9,221,991
13,281,052
Suzuki
876,650
-183,097
-
-265,311
-
-428,242
-
Tesla
49,772
94,733,320
33,896,698
-1,858
-
-128,402,297
275,635
Toyota
80,435,498
21,534,118
-5,457,268
-50,620,615
-
-31,762,431
14,129,302
Volkswagen
6,613,985
-9,321,246
-1,244,913
-1,442,571
-219,419
5,000,000
-614,164
Volvo
730,187
2,696,520
1,512,529
-78,996
-85,163
-851,322
3,923,755
All Manufacturers
234,183,671
57,534,302
-10,697,766
-107,922,178
-50,120,515
J
122,977,514
0
a
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Table 5.20. Distribution of Credits by Expiration Date (Mg)
Final 2023
Credits
Credits
Credits
Credit
Expiring in
Expiring in
Expiring in
Manufacturer
Balance
2024
2025
2026
Aston Martin
63,311
-
5,350
5,489
BMW
1,934,723
420,467
117,904
582,705
BYD Motors
168
168
-
-
Coda
-
-
-
-
Ferrari
7,650
-
-
Fisker
313,070
-
-
-
Ford
8,938,292
-
-
367,875
GM
6,253,376
-
-
-
Honda
34,133,098
11,658,284
2,868,950
4,005,904
Hyundai
3,470,742
-
-
-
Jaguar Land Rover
223,022
-
-
-
Karma
-
-
-
-
Kia
(1,404,557)
-
-
-
Lotus
-
-
-
-
Lucid
307
-
-
-
Mazda
(175,538)
-
-
-
McLaren
12,188
-
-
-
Mercedes
3,706,960
-
-
-
Mitsubishi
1,485,757
392,525
56,866
476,697
Nissan
4,036,351
1,785,335
-
2,231,845
Porsche
-
-
-
-
Rivian
2,600,153
-
-
-
Stellantis
26,382,861
5,938,974
8,443,887
12,000,000
Subaru
13,281,052
5,822,837
3,041,737
2,859,900
Suzuki
-
-
-
-
Tesla
275,635
53,704
208,003
13,928
Toyota
14,129,302
209,503
1,666,470
2,592,586
Volkswagen
(614,164)
-
-
-
Volvo
3,923,755
1,095,257
215,898
71
All Manufacturers
122,977,514
27,377,054
16,625,065
25,137,000
0
a
~
u
Credits Credits Model Year Model Year
Expiring in Expiring in 2023 2022
2027 2028 Deficits Deficits
45,484 6,988
297,241 516,406
1,118,271
4,599,960
1,883,720
3,700
313,070
7,452,146
6,253,376
11,000,000
1,587,022
223,022
-1,287,359
-117,198
307
3,256,742
559,669
19,171
17,738
1,118,214
12,188
450,218
2,582,415
438,364
-175,538
2,460,743
1,100,000
7,200,000
1,512,529
-614,164
16,477,260 39,551,444 -2,077,061
-117,198
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Figure 5.15 shows the overall industry performance, standards, and credit bank for all
years of the GHG program. The industry created a large bank of credits using the early
credits provision in model year 2009 through 2012. For the next three years,
manufacturers continued to generate credits, as the industry GHG performance was below
the industry-wide average standard. At the end of model year 2014, unused early credits
generated from model year 2009 expired, which reduced the overall credit balance. In
model year 2015, the industry again generated credits, however from model year 2016-
2021 the industry GHG performance has been above the standard, resulting in net
withdrawals from the bank of credits to maintain compliance. In addition, unused credits
generated in model years 2010-2016 expired at the end of model year 2021, which further
drew down the overall industry credit balance.
In model year 2023, the overall industry GHG performance fell 18 g/mi to 215 g/mi, while
the standard fell 23 g/mi to 212 g/mi. As a result, the overall industry performance was
above the standard, and the industry generated 11 Tg of deficits. The overall industry
emerged from model year 2023 with a bank of 123 Tg of GHG credits available for future
use, after offsetting all deficits, as seen in Figure 5.15.
The credits available at the end of model year 2023 will expire according to the schedule
defined by the GHG Program and detailed in Table 5.20. An active credit market has
allowed manufacturers to purchase credits to demonstrate compliance, with fifteen
manufacturers selling credits, twenty manufacturers purchasing credits, and approximately
140 credit trades since 2012.
After accounting for the use of credits, and the ability to carry forward a deficit, the industry
overall does not face any non-compliance issues as of the end of the 2023 model year.
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Figure 5.15. Industry Performance and Standards, Credit Generation and Use
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Model Year
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Appendices:
Methods and Additional Data
A. Sources of Input Data
Nearly all of the data for this report are based on automakers' direct submissions to EPA.
EPA has required manufacturers to provide vehicle fuel economy to consumers since 1977
and has collected data on every new light-duty vehicle model sold in the United States
since 1975. The data are obtained either from testing performed by EPA at the National
Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan, or directly from
manufacturers using official EPA test procedures.
National fuel economy standards have been in place in the United States for cars and light
trucks since 1978. The Department of Transportation, through the National Highway Traffic
Safety Administration (NHTSA), has the responsibility for setting and enforcing fuel
economy standards through the Corporate Average Fuel Economy (CAFE) program. Since
the inception of CAFE, EPA has been responsible for establishing test procedures and
calculation methods, and for collecting data used to determine vehicle fuel economy levels.
EPA calculates the CAFE value for each manufacturer and provides it to NHTSA. NHTSA
publishes the final CAFE values in its annual "Summary of Fuel Economy Performance"
reports at https://one.nhtsa.gov/cafe pic/home. Since model year 2012, NHTSA and EPA
have maintained coordinated fuel economy and greenhouse gas standards that apply to
model year 2012 through model year 2032 vehicles. EPA's light-duty GHG program is
described in detail in Section 5 of this report.
The data that EPA collects for this report comprise the most comprehensive database of its
kind. For recent model years, the vast majority of data in this report comes from the
Engines and Vehicles Compliance Information System (EV-CIS) database maintained by EPA.
This database contains a broad amount of data associated with CO2 emissions and fuel
economy, vehicle and engine technology, and other vehicle performance metrics. This
report extracts only a portion of the data from the EV-CIS database.
In some cases, the data submitted by automakers are supplemented by data that were
obtained through independent research by EPA. For example, EPA relied on published data
from external sources for certain parameters of pre-model year 2011 vehicles: (1) engines
with variable valve timing (WT), (2) engines with cylinder deactivation, and (3) vehicle
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footprint, as automakers did not submit this data until model year 2011. EPA projects
footprint data for the preliminary model year 2024 fleet based on footprint values for
existing models from previous years and footprint values for new vehicle designs available
through public sources. In addition, vehicle 0-to-60 acceleration values are not provided by
automakers, but are either calculated from other Trends data, as discussed in Section 3, or
taken from external sources.
The website for this report has been expanded with an emphasis on allowing users to
access and evaluate more of the data behind this report. EPA plans to continue to add
content and tools on the web to allow transparent access to public data. To explore the
data using EPA's interactive data tools, visit the report webpage at
https://www.epa.gov/automotive-trends.
Preliminary vs Final Data
For each model year, automakers submit two phases of data: preliminary data provided
to EPA for vehicle certification and labeling prior to the model year sales, and final data
submitted after the completion of the model year for compliance with EPA's light-duty GHG
regulations and NHTSA's CAFE program.
Preliminary data are collected prior to the beginning of each model year and are not used
for manufacturer GHG compliance. Automakers submit "General Label" information
required to support the generation of the joint EPA/NHTSA Fuel Economy and Environment
Labels that appear on all new personal vehicles. As part of these submissions, automakers
report pre-model year vehicle production projections for individual models and
configurations to EPA.
Final data are submitted a few months after the end of each model year and include
detailed final production volumes. EPA and NHTSA use this final data to determine
compliance with GHG emissions and CAFE standards. These end-of-the-year submissions
include detailed final production volumes. All data in this report for model years 1975
through 2022 are considered final. However, manufacturers can submit requests for
compliance credits for previous model years, so it is possible that additional credits under
the GHG program could be awarded to manufacturers.
Since the preliminary fuel economy values provided by automakers are based on projected
vehicle production volumes, they usually vary slightly from the final fuel economy values
that reflect the actual sales at the end of the model year. With each publication of this
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report, the preliminary values from the previous year are updated to reflect the final
values. This allows a comparison to gauge the accuracy of preliminary projections.
Table A.1 compares the preliminary and final fleetwide real-world fuel economy values for
recent years (note that the differences for CO2 emissions data would be similar, on a
percentage basis). Since model year 2011, the final real-world fuel economy values have
generally been close to the preliminary fuel economy values. In eight out of the last ten
years, manufacturer projections have led to preliminary estimates that were higher than
final data.
It is important to note that there is no perfect apples-to-apples comparison for model years
2011 -2014 due to several small differences in data, such as inclusion of alternative fuel
vehicle (AFV) data. The preliminary values in Table A.1 through model year 2014 did not
integrate AFV data, while the final values in Table A.1 are the values reported elsewhere in
this report and do include AFV data. The differences due to this would be small, on the
order of 0.1 mpgorless.
Table A.1. Comparison of Preliminary and Final Real-World Fuel Economy
Values (mpg)
Model Year
Preliminary
Value
Final Value
Final Minus
Preliminary
2011
22.8
22.3
-0.5
2012
23.8
23.6
-0.2
2013
24.0
24.2
+0.2
2014
24.2
24.1
-0.1
2015
24.7
24.6
-0.2
2016
25.6
24.7
-0.9
2017
25.2
24.9
-0.3
2018
25.4
25.1
-0.3
2019
25.5
24.9
-0.6
2020
25.7
25.4
-0.3
2021
25.3
25.4
+0.1
2022
26.4
26.0
-0.4
2023
26.9
27.1
+0.2
2024 (prelim)
28.0
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B. Harmonic Averaging of Fuel Economy
Values
Averaging multiple fuel economy values must be done harmonically in order to obtain a
correct mathematical result. Since fuel economy is expressed in miles per gallon (mpg), one
critical assumption with any harmonic averaging of multiple fuel economy values is
whether the distance term (miles, in the numerator of mpg) is fixed or variable. This report
makes the assumption that the distance term in all mpg values is fixed, i.e., that for
purposes of calculating a harmonically averaged fuel economy value, it is assumed that the
distance term (representing miles traveled) is equivalent across various vehicle fuel
economies. This assumption is the standard practice with harmonic averaging of multiple
fuel economy values (including, for example, in calculations for CAFE standards
compliance), and simplifies the calculations involved.
Mathematically, when assuming a fixed distance term as discussed above, harmonic
averaging of multiple fuel economy values can be defined as the inverse of the average of
the reciprocals of the individual fuel economy values. It is best illustrated by a simple
example.
Consider a round trip of 600 miles. For the first 300-mile leg, the driver is alone with no
other passengers or cargo, and, aided by a tailwind, uses 10 gallons of gasoline, for a fuel
economy of 30 mpg. On the return 300-mile trip, with several passengers, some luggage,
and a headwind, the driver uses 15 gallons of gasoline, for a fuel economy of 20 mpg. Many
people will assume that the average fuel economy for the entire 600-mile trip is 25 mpg,
the arithmetic (or simple) average of 30 mpg and 20 mpg. But, since the driver consumed
10 + 15 = 25 gallons of fuel during the trip, the actual fuel economy is 600 miles divided by
25 gallons, or 24 mpg.
Why is the actual 24 mpg less than the simple average of 25 mpg? Because the driver used
more gallons while (s)he was getting 20 mpg than when (s)he was getting 30 mpg.
This same principle is often demonstrated in elementary school mathematics when an
airplane makes a round trip, with a speed of 400 mph one way and 500 mph the other way.
The average speed of 444 mph is less than 450 mph because the airplane spent more time
going 400 mph than it did going 500 mph.
As in both of the examples above, a harmonic average will typically yield a result that is
slightly lower than the arithmetic average.
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The following equation illustrates the use of harmonic averaging to obtain the correct
mathematical result for the fuel economy example above:
2
Average mpg =
Though the above example was for a single vehicle with two different fuel economies over
two legs of a single round trip, the same mathematical principle holds for averaging the fuel
economies of any number of vehicles. For example, the average fuel economy for a set of 10
vehicles, with three 30 mpg vehicles, four 25 mpg vehicles, and three 20 mpg vehicles would
be
(Note that, in order to maintain the concept of averaging, the total number of vehicles in the
numerator of the equation must equal the sum of the individual numerators in the
denominator of the equation.)
Arithmetic averaging, not harmonic averaging, provides the correct mathematical result for
averaging fuel consumption values (in gallons per mile, the inverse of fuel economy) and CO2
emissions (in grams per mile). In the first, round trip, example above, the first leg had a fuel
consumption rate of 10 gallons over 300 miles, or 0.033 gallons per mile. The second leg had
a fuel consumption of 15 gallons over 300 miles, or 0.05 gallons per mile. Arithmetically
averaging the two fuel consumption values, i.e., adding them up and dividing by two, yields
0.04167 gallons per mile, and the inverse of this is the correct fuel economy average of 24
mpg. Arithmetic averaging also works for CO2 emissions values, i.e., the average of 200 g/mi
and 400 g/mi is 300 g/mi C02 emissions.
In summary, fuel economy values must be harmonically averaged to maintain mathematical
integrity, while fuel consumption values (in gallons per mile) and CO2 emissions values (in
grams per mile) can be arithmetically averaged.
10
Average mpg = : = 24.4 mpg
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C. Fuel Economy and CO2 Metrics
The C02 emissions and fuel economy data in this report fall into one of two categories:
compliance data and estimated real-world data. These categories are based on the
purpose of the data, and the subsequent required emissions test procedures. The
following sections discuss the differences between compliance and real-world data and
how they relate to raw vehicle emissions test results.
2-Cycle Test Data
In 1975 when the Corporate Average Fuel Economy (CAFE) regulation was put into place,
EPA tested vehicles using two dynamometer-based test cycles, one based on city driving
and one based on highway driving. CAFE wasand continues to berequired by law to use
these "2-cycle tests". For consistency, EPA also adopted this approach for the GHG
regulations.
Originally, the fuel economy values generated from the "2-cycle" test procedure were used
both to determine compliance with CAFE requirements and to inform consumers of their
expected fuel economy via the fuel economy label. Today, the raw 2-cycle test data are
used primarily in a regulatory context as the basis for determining the final compliance
values for CAFE and GHG regulations.
The 2-cycle testing methodology has remained largely unchanged28 since the early 1970s.
Because of this, the 2-cycle fuel economy and CO2 values can serve as a useful comparison
of long-term trends. Previous versions of this report included 2-cycle fuel economy and CO2
data, referred to as "unadjusted" or "laboratory" values. These 2-cycle fuel economy values
are still available on the report website for reference. It is important to note that these 2-
cycle fuel economy values do not exactly correlate to the 2-cycle tailpipe CO2 emissions
values provided in Section 5 for the GHG regulations. There are three methodological
reasons for this:
28 There were some relatively minor test procedure changes made in the late 1970s that, in the aggregate,
made the city and highway tests slightly more demanding, i.e., the unadjusted fuel economy values for a given
car after these test procedure changes were made are slightly lower relative to prior to the changes. EPA has
long provided CAFE "test procedure adjustments" (TPAs) for passenger cars in recognition of the fact that the
original CAFE standards were based on the EPA test procedures in place in 1975 (there are no TPAs for light
trucks). The resulting impacts on the long-term unadjusted fuel economy trends are very small. The TPAs for
cars vary but are typically in the range of 0.2-0.5 mpg for cars, or 0.1-0.3 mpg when the car TPAs are averaged
over the combined car/truck fleet.
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1. The GHG regulations require a car and truck weighting based on a slightly higher
lifetime vehicle miles traveled (VMT) for trucks. The 2-cycle fuel economy values do
not account for this difference.
2. The GHG regulations allow manufacturers to use an optional compliance approach,
which adds nitrous oxide and methane emissions to their 2-cycle CO2 emissions.
3. The GHG regulations and CAFE regulations result in very slightly different annual
production values. Prior to model year 2017, the 2-cycle fuel economy values rely on
CAFE production values (see Appendix D).
GHG Compliance Data
Compliance data in this report are used to determine how the manufacturers are
performing under EPA's GHG program. These data are reported in the Executive Summary
and Section 5. The 2-cycle C02 test values form the basis for the compliance data, but there
are some important differences due to provisions in the standards. Manufacturers' model
year performance is calculated based on the measured 2-cycle CO2 tailpipe emissions as
well as optional performance credits and adjustments that manufacturers may qualify for
and use.
Compliance data also includes the overall credit balances held by each manufacturer, and
may incorporate credit averaging, banking, and trading by manufacturers. The compliance
process is explained in detail in Section 5. Compliance C02 data is not comparable to
estimated real-world CO2 data, as described below.
Estimated Real-World Fuel Economy and CO2 Data
Estimated real-world (previously called "adjusted") data is EPA's best estimate of real-world
fuel economy and CO2 emissions, as reported in Sections 1 -4 of this report. The real-world
values are the best data for researchers to evaluate new vehicle C02 and fuel economy
performance. Unlike compliance data, the method for calculating real-world data has
evolved over time, along with technology and driving habits. These changes in
methodology are detailed in Appendix D.
Calculating estimated real-world fuel economy
Estimated real-world fuel economy data are currently measured based on the "5-cycle" test
procedure that utilizes high-speed, cold start, and air conditioning tests in addition to the 2-
cycle tests to provide data more representative of real-world driving. These additional
laboratory tests capture a wider range of operating conditions (including hot/cold weather
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and higher acceleration) that an average driver will encounter. City and highway results are
weighted 43% / 57%, consistent with fleetwide driver activity data.
Calculating estimated real-world CO2 emissions
The estimated real-world C02 emissions shown in Sections 1-4 are not based directly on
the 2-cycle tested values, but rather they are based on calculated values that convert
estimated real-world fuel economy values to CO2 using emission factors. This approach is
taken because: 1) test data are not available for most historic years of data, and 2) some
manufacturers choose to use an optional compliance approach which adds nitrous oxide
(N2O) and methane (CH4) emissions to their CO2 emissions (also referred to as Carbon
Related Exhaust Emissions, or CREE), leading to slightly different test results.
The estimated real-world C02 emissions from gasoline vehicles are calculated by dividing
8,887 g/gal by the fuel economy of the vehicle. The 8,887 g/gal emission factor is a typical
value for the grams of CO2 per gallon of gasoline test fuel and assumes all the carbon is
converted to CO2. For example, 8,887 g/gal divided by a gasoline vehicle fuel economy of 30
mpg would yield an equivalent CO2 emissions value of 296 grams per mile.
The estimated real-world CO2 emissions for diesel vehicles are calculated by dividing
10,180 g/gal by the diesel vehicle fuel economy value. The 10,180 g/gal diesel emission
factor is higher than for a gasoline vehicle because diesel fuel has a 14.5% higher carbon
content per gallon than gasoline. Accordingly, a 30-mpg diesel vehicle would have a C02
equivalent value of 339 grams per mile. Emissions for vehicles other than gasoline and
diesel are also calculated using appropriate emissions factors.
Example Comparison of Fuel Economy Metrics
The multiple ways of measuring fuel economy and GHG emissions can understandably
lead to confusion. As an illustration to help the reader understand the various fuel
economy values that can be associated with an individual vehicle, Table 1.2 shows three
different fuel economy metrics for the model year 2024 Toyota Prius. The 2-cycle city and
highway fuel economy values are direct fuel economy measurements from the 2-cycle tests
and are harmonically averaged with a 55% city / 45% highway weighting to generate a
combined value. The 2-cycle laboratory tested city fuel economy of the Prius is 83 mpg, the
highway fuel economy is 78 mpg, and the combined 2-cycle value is 80 mpg.
Using the 5-cycle methodology, the Toyota Prius has a vehicle fuel economy label value of
57 mpg city and 56 mpg highway. On the vehicle label, these values are harmonically
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averaged using a 55% city / 45% highway weighting to determine a combined value of 57
mpg. The estimated real-world fuel economy for the Prius, which is the set of values used
in calculations for this report, has the same city and highway fuel economy as the label, but
the 43% city and 57% highway weighting leads to a combined value of 56 mpg, which is one
mpg less than the values found on the label.
Table C.1. Fuel Economy Metrics for the Model Year 2024 Toyota Prius
Fuel
Fuel Economy Value
(MPG)
Economy
Metric
Purpose
City/ Highway
Weighting
Test
Basis
Combined
City/Hwy
City
Hwy
2-cycle Test
(unadjusted)
Basis for manufacturer
compliance with
standards
55% / 45%
2-cycle
80
83
78
Label
Consumer information
to compare individual
vehicles
55% / 45%
5-cycle
57
57
56
Estimated
Real-World
Best estimate of real-
world performance
43% / 57%
5-cycle
56
57
56
Greenhouse Gases other than CO2
In addition to tailpipe CO2 emissions, vehicles may create greenhouse gas emissions in
several other ways. The combustion process can result in emissions of N2O, and CH4, and
leaks in vehicle air conditioning systems can release refrigerants, which are also
greenhouse gases, into the environment. N20, CH4, and air conditioning greenhouse gases
are discussed as part of the GHG regulatory program in Section 5. Estimated real-world CO2
emissions in Sections 1 -4 only account for tailpipe CO2 emissions.
The life cycle of the vehicle (including manufacturing and vehicle disposal) and the life cycle
of the fuels (including production and distribution) can also create significant greenhouse
gases. Life cycle implications of vehicles and fuels can vary widely based on the vehicle
technology and fuel and are outside the scope of this report. However, there is academic
research, both published and ongoing, in this area for interested readers.
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D. Historical Changes in the Database and
Methodology
Over the course of this report's publication, there have been some instances where
relevant methodologies and definitions have been updated. Since the goal of this report is
to provide the most accurate data and science available, updates are generally propagated
back to through the historical database. The current version of this report supersedes all
previous reports.
Changes in Estimated Real-world Fuel Economy and CO2
The estimated real-world fuel economy values in this report are closely related to the label
fuel economy values. Over the course of this report, there have been three updates to the
fuel economy label methodology (for model years 1985, 2008, and 2017), and these
updates were propagated through the Trends database. However, there are some
important differences in how the label methodology updates have been applied in this
report. This section discusses how these methodologies have been applied, partially or in
full, to the appropriate model years based on the authors' technical judgement. The
changes are intended to provide accurate real-world values for vehicles at the time they
were produced to better reflect available technologies, changes in driving patterns, and
composition of the fleet. These changes are also applicable to real-world CO2 values, which
are converted from fuel economy values using emissions factors.
Model year 1975-1985: Universal Multipliers
The first change to the label methodology occurred when EPA recognized that changing
technology and driving habits led to real-world fuel economy results that over time were
diverging from the fuel economy values measured using the 2-cycle tests. To address this
issue, EPA introduced an alternative calculation methodology in 1985 that applied a
multiplication factor to the 2-cycle test data of 0.9 for city and 0.78 for highway. The
estimated real-world fuel economy values from model year 1975-1985 in this report were
calculated using the same multiplication factors that were required for the model year
1985 label update. The authors believe that these correction factors were appropriate for
new vehicles from model year 1975 through 1985. The combined fuel economy and CO2
values are based on a 55% city / 45% highway weighting factor, consistent with the CAFE
and label fuel economy calculations.
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Model year 1986-2010: The 2006 5-cycle methodology and 43% City / 57%
Highway Weighting
In 2006, EPA established a major change to the fuel economy label calculations by
introducing the 5-cycle methodology29. In addition to the city and highway tests required
for 2-cycle fuel economy the 5-cycle methodology introduces tests for high speeds (US06),
air-conditioning (SC03), and a cold temperature test. It also indirectly accounts for a
number of other factors that are not reflected in EPA laboratory test data (e.g., changing
fuel composition, wind, road conditions) through the use of a 9.5% universal downward
adjustment factor. The change from the universal adjustment factors to the 2006 5-cycle
method lowered estimated real-world fuel economy values, particularly for high fuel
economy vehicles. In the 2006 rulemaking, EPA projected an overall average fleetwide
adjustment of 11 % lower for city fuel economy and 8% lower for highway fuel economy.
For model year 1986-2004, the authors implemented the 2006 5-cycle methodology by
assuming the changes in technology and driver behavior that led to lower real-world fuel
economy occurred in a gradual, linear manner over 20 years. We did not attempt to
perform a year-by-year analysis to determine the extent to which the many relevant factors
(including higher highway speed limits, more aggressive driving, increasing vehicle
horsepower-to-weight ratios, suburbanization, congestion, greater use of air conditioning,
gasoline composition, etc.) that have affected real-world fuel economy since 1985 have
changed over time.
Under the 5-cycle methodology, manufacturers could either: 1) perform all five tests on
each vehicle (the "full 5-cycle" method), 2) use an alternative analytical "derived 5-cycle"
method based on 2-cycle testing if certain conditions were met, or 3) voluntarily use lower
fuel economy label estimates than those resulting from the full 5-cycle or derived 5-cycle. If
manufacturers are required to perform all five tests, the results are weighted according to
composite 5-cycle equations.30 To use the derived 5-cycle method, manufacturers are
required to evaluate whether fuel economy estimates using the full 5-cycle tests are
comparable to results using the derived 5-cycle method. In recent years, the derived 5-cycle
approach has been used to generate approximately 85% of all vehicle label fuel economy
values.
29 See 71 Federal Register 77872, December 27, 2006.
30 See 71 Federal Register 77883-77886, December 27, 2006.
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For vehicles that were eligible to use the 2006 derived 5-cycle methodology, the following
equations were used to convert 2-cycle city and highway fuel economy values to label
economy values. These equations were based on the relationship between 2-cycle and 5-
cycle fuel economy data for the industry as a whole.
1
Label CITY =
(o.003259 + 2CYCLE CITy)
Label HWY =
(0.001376 +
1.3466
2 CYCLE HWY J
Over the same timeframe, EPA phased in a change in the city and highway weightings used
to determine a single combined fuel economy or C02 value. EPA's analysis of real-world
driving activity underlying the 5-cycle fuel economy methodology assumed a "speed
cutpoint" of 45 miles per hour to differentiate between (and "bin" the amount of) city and
highway driving.31 Based on this speed cutpoint, the correct weighting for correlating the
new city and highway fuel economy values with real-world driving activity data from on-
road vehicle studies, on a miles driven basis, is 43% city and 57% highway; this updated
weighting is necessary to maintain the integrity of fleetwide fuel economy performance
based on Trends data. The 55% city and 45% highway weighting is still used for both Fuel
Economy and Environment Labels and the CAFE and GHG emissions compliance programs.
The authors used the same gradual, linear approach to phase in the change in city and
highway weightings along with the phase-in of the 2006 5-cycle methodology.
From model year 2005 to model year 2010, the 2006 5-cycle methodology and the 43% city
and 57% highway weightings were used to determine the real-world fuel economy values
for this report. This required using the derived 5-cycle equations and the 43% city and 57%
highway weightings to recalculate real-world fuel economy values for model year 2005 to
2007, because the 2006 5-cycle methodology was not required until 2008. Model year 2008
to model year 2010 real-world fuel economy values were the same as the label fuel
economy values, except for the city and highway weightings.
31 See 71 Federal Register 77904, December 27, 2006.
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Model year 2011 -present: Implementing the 2017 derived 5-cycle updates
In 2015, EPA released a minor update to the derived 5-cycle equations that modified the
coefficients used to calculate derived 5-cycle fuel economy from 2-cycle test data.32 This
update was required under existing regulations and applies to fuel economy label
calculations for all model year 2017 and later vehicles. The following equations are used to
convert 2-cycle test data values for city and highway to label fuel economy values:
1
Label CITY =
(o.004091 +
1.1601
Label HWY =
2CYCLE CITYV
1
(0.003191 +
1.2945
2 CYCLE HWYJ
The updated 5-cycle calculations introduced for model year 2017 and later labels were
based on test data from model year 2011 to model year 2016 vehicles. Therefore, the
authors chose to retroactively apply the updated 5-cycle methodology to model years 2011
to 2016. This required recalculating the real-world fuel economy of vehicles from model
year 2011 to 2016 using the new derived 5-cycle equations. Vehicles that conducted full 5-
cycle testing or voluntarily lowered fuel economy values were unchanged. The 43% city and
57% highway weightings were maintained. The changes for model years 2011 -2016 due to
the 5-cycle update were relatively small (0.1 to 0.2 mpg overall) and did not noticeably alter
the general data trends, therefore the authors determined that a phase-in period was not
required for this update.
Figure D.1 below summarizes the impact of the changes in real-world data methodology
relative to the 2-cycle test data, which has had a consistent methodology since 1975. Over
time, the estimated real-world fuel economy of new vehicles has continued to slowly
diverge from 2-cycle test data, due largely to changing technology, driving patterns, and
vehicle design. See Appendix C for more information.
32 See https://www.epa.gov/fueleconomy/basic-information-fuel-economy-labeling and
http://iaspub.epa.gov/otaqpub/display file.jsp?docid=35113&flag=1
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Figure D.1. Estimated Real-World versus 2-Cycle Fuel Economy since Model
Year 1975
Phase I Phase II Phase III Phase IV
1975-1985 1986-2006 2007-2010 2011-present
Universal 2006 5-cycle is phase-in 5-cycle Updated 5-cycle
adjustment factors 43/57°/
55/45% weighting 43/57% weighting phase-in weighting 43/57% weighting
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
2-cycle method
unchanged
since 1975
Estimated
Real-World
Phases I - IV
Other Database Changes
Addition of Medium-Duty Passenger Vehicles
Beginning in 2011 medium-duty passenger vehicles (MDPVs), those SUVs and passenger
vans (but not pickup trucks) with gross vehicle weight ratings between 8,500 and 10,000
pounds, are included in the light-duty truck category. This coincided with new regulations
by NHTSA to treat these vehicles as light-duty, rather than heavy-duty, vehicles beginning in
model year 2011, This represents a minor change to the database, since the number of
MDPVs is much smaller than it once was (e.g., only 6,500 MDPVs were sold in model year
2012). It should be noted that this is one change to the database that has not been
propagated back through the historic database, as we do not have MDPV data prior to
model year 2011. Accordingly, this represents a small inflection point for the database for
the overall car and truck fleet in model year 2011; the inclusion of MDPVs decreased
average real-world fuel economy by 0.01 mpg and increased average real-world CO2
emissions by 0.3 g/mi, compared to the fleet without MDPVs. The impacts on the truck fleet
only were about twice as high, but still very small in absolute terms. Pickup trucks above
8,500 pounds are not included in this report.
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Addition of Alternative Fuel Vehicles
Data from alternative fuel vehicles are integrated into the overall database, beginning with
MY 2011 data. These vehicles include electric vehicles, plug-in hybrid electric vehicles, fuel
cell vehicles, and compressed natural gas vehicles. C02 emissions from alternative fuel
vehicles represent tailpipe emissions, and fuel economy for these vehicles is reported as
mpge (miles per gallon of gasoline equivalent), or the miles an alternative fuel vehicle can
travel on an amount of energy equivalent to that in a gallon of gasoline. Sales data prior to
MY 2011 are included in some cases based on available industry reports (e.g., Ward's
Automotive data).
Changes in Vehicle Classification Definitions
The car-truck classifications in this report follow the current regulatory definitions used by
EPA and NHTSA for compliance with GHG emissions and CAFE standards (see definitions
for passenger automobiles (cars) and non-passenger automobiles (trucks) in 49 CFR 523).
These current definitions differ from those used in the 2010 and older versions of the Light-
Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report, and
reflect a decision by NHTSA to reclassify many small, 2-wheel drive sport utility vehicles
(SUVs) from the light truck category to the passenger car category, beginning with model
year 2011. When this re-classification was initiated in the 2011 report, the absolute truck
share decreased by approximately 10%.
The current car-truck definitions have been propagated back throughout the entire
historical Trends database to maintain the integrity of long-term trends of car and truck
production share. Since the authors did not have all of the requisite technical information
on which to make retroactive car-truck classifications, we used engineering judgment to
classify past models.
This report previously presented data on more vehicle types, but recent vehicle design has
led to far less distinction between vehicle types and reporting on more disaggregated
vehicle types was no longer useful.
Manufacturer Definitions
When a manufacturer grouping changes under the GHG and CAFE programs, the current
manufacturer definitions are generally applied to all prior model years. This maintains
consistent manufacturer and make definitions over time, which enables better
identification of long-term trends. However, some of the compliance data maintain the
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previous manufacturer definitions where necessary to preserve the integrity of compliance
data as they were accrued.
Differences in Production Data Between CAFE and GHG Regulations
The data used to discuss real-world trends in Sections 1 through 4 of this report are based
on production volumes reported under CAFE prior to model year 2017, not the GHG
standards. The production volume levels automakers provide in their final CAFE reports
may differ slightly from their final GHG reports (typically less than 0.1 %) because of
different reporting requirements. The EPA regulations require emission compliance in the
50 states, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa,
and the Commonwealth of the Northern Mariana Islands, whereas the CAFE program
requires data from the 50 states, the District of Columbia, and Puerto Rico only. All
compliance data detailed in Section 5, for all years, are based on production volumes
reported under the GHG standards. Starting with model year 2017 and forward, the real-
world data are also based on production volumes reported under EPA's GHG standards. As
described above, the difference in production volumes is very small and does not impact
the long-term trends or analysis.
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E. Electric Vehicle and Plug-In Hybrid
Metrics
Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles (PHEVs) have continued
to gain market share. Overall market penetration of these vehicles is projected to reach
15% production share in model year 2024. This section addresses some of the technical
metrics used both to quantify BEV and PHEV operation and to integrate data from these
vehicles with gasoline and diesel vehicle data.
BEVs operate using only energy stored in a battery from external charging. PHEVs blend
BEV technology with more familiar powertrain technology from petroleum-fueled vehicles.
Current PHEVs feature both an electric drive system designed to be charged from an
electricity source external to the vehicle (like a BEV) and a gasoline internal combustion
engine. There are generally three ways that a PHEV can operate:
Charge-depleting electric-only mode - The vehicle operates like a BEV, using only
energy stored in the battery to propel the vehicle.
Charge-depleting blended mode - The vehicle uses both energy stored in the
battery and energy from the gasoline tank to propel the vehicle. Depending on the
vehicle design and driving conditions, blended operation can include substantial
all-electric driving.
Charge-sustaining mode - The vehicle has exhausted the stored energy in the
battery and relies on the gasoline internal combustion engine. In this mode, the
vehicle will operate much like a strong hybrid.
The presence of both electric drive and an internal combustion engine within one
powertrain results in a complex system that can be used in many different combinations,
and manufacturers are choosing to operate PHEV systems in different ways to optimize
efficiency and performance. This complicates direct comparisons among PHEV models.
This section discusses BEV and PHEV metrics for several example model year 2024 vehicles.
For consistency and clarity for the reader, the data for specific vehicles discussed in this
section reflect values from the EPA/DOT Fuel Economy and Environment Labels, which use
a 55% city and 45% highway weighting for combined fuel economy and CO2 values. When
data for these vehicles are integrated into the data for the rest of the report, the real-world
highway and city values are combined using a 43% city and 57% highway weighting.
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Additionally, some PHEV calculations are also adjusted, as explained at the end of this
section.
Table E.1 shows the label driving range for several BEVs and PHEVs when operating only on
electricity, as well as the total electricity plus gasoline range for PHEVs. The average range
of new BEVs is increasing, as shown in Section 4, and many BEVs are approaching the range
of an average gasoline vehicle.33 PHEVs generally have a much smaller all electric range,
however the combined electric and gasoline range for PHEVs often exceeds gasoline-only
vehicles. Several PHEVs now exceed 500 miles of total range.
Table E.1. Model Year 2024 Example BEV and PHEV Powertrain and Range
Manufacturer
Model
Fuel or
Power-
train
Electric
Range
(miles)
Total
Range
(miles)
Utility
Factor
Ford
F-150 Lightning Platinum
BEV
300
300
-
GM
Equinox EV AWD
BEV
285
285
-
Hyundai
loniq 6 LR AWD 18" wheels
BEV
316
316
-
Nissan
Leaf SV
BEV
212
212
-
Tesla
Model 3 LR AWD
BEV
342
342
-
BMW
XM
PHEV
31
300
0.60
Stellantis
Pacifica Hybrid
PHEV
32
520
0.61
Toyota
Prius Prime SE
PHEV
45
600
0.71
Volvo
XC60 T8AWD Recharge
PHEV
36
560
0.64
Determining the electric range of PHEVs is complicated if the vehicle is capable of operating
in blended modes. For PHEVs like the Toyota Prius Prime SE, which cannot operate in
blended mode, the electric range represents the estimated range operating in electric only
mode. However, for PHEVs that operate in a blended mode, the electric range represents
the estimated range of the vehicle operating in either electric only or blended mode, due to
the design of the vehicle. For example, the Volvo XC60 Recharge uses electricity stored in its
battery and a small amount of gasoline to achieve an alternative fuel range of 35 miles.
Most PHEVs did not use any gasoline to achieve their electric range value on EPA test
cycles; however, certain driving conditions (e.g., more aggressive accelerations, higher
33 In addition to growing EV range, the number of public electric vehicle charging stations is growing rapidly. For
more information, see the U.S. Department of Energy's Alternative Fuels Data Center at
h tt ps: //www, af d c. e n e rgv. gov/.
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speeds, and air conditioning or heater operation) would likely cause these vehicles to
operate in a blended mode instead of an all-electric mode.
Table E.1 also introduces the concept of a utility factor. The utility factor is directly related
to the electric range for PHEVs and is a projection, on average, of the percentage of miles
that will be driven using electricity (in electric-only and blended modes) by an average
driver. The model year 2024 Prius Prime SE, for example, has a utility factor of 0.71, i.e., it is
expected that, on average, the Prius Prime SE will operate 71 % of the time on electricity
and 29% of the time on gasoline. The label utility factor calculations are based on the SAE
methodologyJ2841 that EPA has adopted for fuel economy labeling (SAE 2010).
Table E.2 shows five energy-related metrics for model year 2024 example EVs and PHEVs
that are included on the EPA/NHTSA Fuel Economy and Environment labels. Comparing the
energy or fuel efficiency performance from alternative fuel vehicles raises complex issues
of how to compare different fuels. Consumers and OEMs are familiar and comfortable with
evaluating gasoline and diesel vehicle fuel economy in terms of miles per gallon, and it is
the primary efficiency metric in this report. To enable this comparison for alternative fuel
vehicles, the overall energy efficiency of vehicles operating on electricity, hydrogen, and
CNG are evaluated in terms of miles per gallon of gasoline equivalent (an energy metric
described in more detail below).
Table E.2. Model Year 2024 Example EV and PHEV Fuel Economy Label Metrics
Manufacturer
Model
Fuel or
Power-
train
Charge Depleting
Charge
Sustaining
Overall
Fuel
Economy
(mpge)
Electricity
(kW-hrs/
100 miles)
Gasoline
(gallons/
100
miles)
Fuel
Economy
(mpge)
Fuel
Economy
(mpg)
Ford
F-150 Lightning
BEV
51
N/A
66
N/A
66
Platinum
GM
Equinox EV AWD
BEV
35
N/A
96
N/A
96
Hyundai
loniq 6 LR AWD
BEV
28
N/A
121
N/A
121
Nissan
Leaf SV
BEV
31
N/A
109
N/A
109
Tesla
Model 3 LR AWD
BEV
26
N/A
130
N/A
130
BMW
XM
PHEV
73
0.0
46
14
24
Stellantis
Pacifica Hybrid
PHEV
41
0.0
82
30
48
Toyota
Prius Prime SE
PHEV
26
0.0
127
52
89
Volvo
XC60 T8 AWD
PHEV
50
0.1
63
28
44
Recharge
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The fourth column in Table E.2 gives electricity consumption rates for BEVs and PHEVs
during charge depleting operation in units of kilowatt-hours per 100 miles (kW-hrs/100
miles). As shown on the vehicle label, the electricity consumption rate is based on the
amount of electricity required from an electric outlet to charge the vehicle and includes
wall-to-vehicle charging losses. The values for all of the BEVs and PHEVs reflect the
electricity consumption rate required to operate the vehicle in either electric-only or
blended mode operation. PHEVs that are capable of operating in a blended mode may also
consume some gasoline in addition to electricity. Any additional gasoline used is shown in
the fifth column. For example, the Volvo XC60 Recharge consumes 50 kW-hrs and 0.1
gallons of gasoline per 100 miles during this combination of electric-only and blended
modes.
The sixth column converts the electricity consumption data in the fourth column and the
gasoline consumption data in the fifth column into a combined miles per gallon of
gasoline-equivalent (mpge) metric. The mpge metric is a measure of the miles the vehicle
can travel on an amount of energy that is equal to the amount of energy stored in a gallon
of gasoline. For a vehicle operating on electricity, mpge is calculated as 33.705 kW-
hrs/gallon divided by the vehicle electricity consumption in kW-hrs/mile. For example, for
the Leaf, 33.705 kW-hrs/gallon divided by 0.31 kW-hrs/mile (equivalent to 31 kW-hrs/100
miles) is 109 mpge.34 Because the Volvo XC60 Recharge consumes both electricity and
gasoline over the alternative fuel range of 35 miles, the charge depleting fuel economy of
63 mpge includes both the electricity and gasoline consumption, at a rate of 50 kW-hrs/100
miles of electricity and 0.1 gal/100 miles of gasoline.
The seventh column gives label fuel economy values for vehicles operating on gasoline
only, which is relevant here only for the PHEVs operating in charge sustaining mode. For
PHEVs, the EPA/NHTSA label shows both electricity consumption in kW-hrs/100 miles and
mpge, when the vehicle operates exclusively on electricity or in a blended mode, and
gasoline fuel economy in mpg, when the vehicle operates exclusively on gasoline.
The final column gives the overall mpge values reflecting the overall energy efficiency of
the vehicle for all of the fuels on which the vehicle can operate and provide a common
metric to compare vehicles that operate on different fuels. In addition to the energy
metrics in the previous columns, the one key additional parameter necessary to calculate a
combined electricity/gasoline mpge value for a PHEV is the utility factor that was
34 The actual calculations were done with unrounded numbers. Using the rounded numbers provided here may
result in a slightly different number due to rounding error.
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introduced in Table E.1. For EVs, the overall fuel economy in the last column is equal to the
charge depleting fuel economy, as EVs can only operate in a charge depleting mode.
Table E.3 gives vehicle tailpipe CO2 emissions values that are included on the EPA/DOT Fuel
Economy and Environment labels (and reflected in the label's Greenhouse Gas Rating).
These label values reflect EPA's best estimate of the CO2 tailpipe emissions that these
vehicles will produce, on average, in real-world city and highway operation. EVs, of course,
have no tailpipe emissions. For the PHEVs, the label CO2 emissions values utilize the same
utility factors discussed above to weight the CO2 emissions on electric and gasoline
operation.
Table E.3. Model Year 2024 Example EV and PHEV Label Tailpipe CO2 Emissions
Metrics
Manufacturer
Model
Fuel or
Powertrain
Tailpipe C02
(g/mile)
Ford
F-150 Lightning Platinum
BEV
0
GM
Equinox EV AWD
BEV
0
Hyundai
loniq 6 LR AWD 18" wheels
BEV
0
Nissan
Leaf SV
BEV
0
Tesla
Model 3 LR AWD
BEV
0
BMW
XM
PHEV
244
Stellantis
Pacifica Hybrid
PHEV
119
Toyota
Prius Prime SE
PHEV
50
Volvo
XC60 T8 AWD Recharge
PHEV
122
Table E.4 accounts for the "upstream" CO2 emissions associated with the production and
distribution of electricity used in BEVs and PHEVs. Gasoline and diesel fuels also have CO2
emissions associated with their production and distribution, but these upstream emissions
are not reflected in the tailpipe C02 emissions values discussed elsewhere in this report.
Combining vehicle tailpipe and fuel production/distribution sources, gasoline vehicles emit
about 80 percent of total CO2 emissions at the vehicle tailpipe with the remaining 20
percent of total CO2 emissions associated with upstream fuel production and distribution.
Diesel fuel has a similar approximate relationship between tailpipe and upstream CO2
emissions. On the other hand, vehicles powered by grid electricity emit no C02 (or other
emissions) at the vehicle tailpipe; therefore, all CO2 emissions associated with a BEV are
due to fuel production and distribution. Depending on how the electricity is produced,
these fuels can have very high fuel production/distribution CO2 emissions (for example, if
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coal is used with no CO2 emissions control) or very low CO2 emissions (for example, if
renewable processes with minimal fossil energy inputs are used).
Electricity production in the United States varies significantly from region to region and has
been changing over time. Hydroelectric plants provide a large percentage of electricity in
the Northwest, while coal-fired power plants produce the majority of electricity in the
Midwest. Natural gas, wind, and solar have increased their electricity market share in many
regions of the country. Natural gas plants currently make up most of the balance of U.S.
electricity production. In order to bracket the possible GHG emissions impact, Table E.4
provides ranges with the low end of the range corresponding to the California power plant
GHG emissions factor, the middle of the range represented by the national average power
plant GHG emissions factor, and the high end of the range corresponding to the power
plant GHG emissions factor for part of the Midwest (Illinois and Missouri).
Table E.4. Model Year 2024 Example EV and PHEV Upstream CO2 Emission
Metrics (g/mi)
Tailpipe + Total Tailpipe + Net
Fuel or
Powertrain
Upstream CO;
I
Upstream CO;
I
Manufacturer
Model
Low
Avg
High
Low
Avg
High
Ford
F-150 Lightning
Platinum
BEV
132
211
340
45
124
253
GM
Equinox EVAWD
BEV
91
146
235
31
86
175
Hyundai
loniq 6AWD 18"
BEV
73
116
188
18
61
133
Nissan
Leaf SV
BEV
80
128
206
33
81
159
Tesla
Model 3 LRAWD
BEV
67
107
173
15
55
121
BMW
XM
PHEV
419
488
599
315
383
495
Stellantis
Pacifica Hybrid
PHEV
214
254
318
140
179
243
Toyota
Prius Prime SE
PHEV
111
139
186
63
92
139
Volvo
XC60 T8 AWD
Recharge
PHEV
236
286
368
164
214
295
Average Sedan/Wagon
280
280
280
224
224
224
Based on data from EPA's eGRID power plant database,35 and accounting for additional
greenhouse gas emissions impacts for feedstock processing upstream of the power
plant,36 EPA estimates that the electricity CO2 emission factors for various regions of the
35 United States Environmental Protection Agency (EPA). 2024. "Emissions & Generation Resource Integrated
Database (eGRID), 2022" Washington, DC: Office of Atmospheric Programs, Clean Air Markets Division. Available
from EPA's eGRID web site: https://www.epa.gov/egrid.
36Argonne National Laboratory 2024. GREET_1_2023rev1 Model, greet.es.anl.gov.
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country vary from 260 g C02/kW-hr in California to 670 g C02/kW-hr in the Midwest (Illinois
and Missouri), with a national average of 416 g C02/kW-hr. Emission rates for small regions
in upstate New York and Alaska have lower electricity upstream C02 emission rates than
California. However, California is a good surrogate for the "low" end of the range because
California is a leading market for current BEVs and PHEVs. Initial sales of electric vehicles
have been largely, though not exclusively, focused in regions of the country with power
plant CO2 emissions factors lower than the national average, such as California, New York,
and other coastal areas. Accordingly, in terms of C02 emissions, EPA believes that the
current "sales-weighted average" vehicle operating on electricity in the near term will likely
fall somewhere between the low end of this range and the national average.37
The fourth through sixth columns in Table E.4 provide the range of tailpipe plus total
upstream CO2 emissions for BEVs and PHEVs based on regional electricity emission rates.
For comparison, the average model year 2024 car is also included in the last row of Table
E.4. The methodology used to calculate the range of tailpipe plus total upstream CO2
emissions for BEVs is shown in the following example for the model year 2024 Nissan Leaf
SV:
Start with the label (5-cycle values weighted 55% city / 45% highway) vehicle
electricity consumption in kW-hr/mile, which for the Leaf is 31 kW-hr/100 miles, or
0.31 kW-hr/mile
Determine the regional powerplant emission rate, regional losses during electricity
distribution, and the additional regional emissions due to fuel production upstream
of the powerplant (for California, these numbers are 241 g/kW-hr, 5.1%, and 9.3%,
respectively).
Determine the regional upstream emission factor (for California 226 g/kW-hr / (1 -
0.051) * (1 +0.093) = 260 g C02/kW-hr)38
Multiply by the range of Low (California = 260g C02/kW-hr), Average (National
Average = 416 g C02/kW-hr), and High (Midwest = 670 g C02/kW-hr) electricity
upstream CO2 emission rates, which yields a range for the Leaf of 80-206 grams
C02/mile.
37 To estimate the upstream greenhouse gas emissions associated with operating a BEV or PHEV in a specific
geographical area, use the emissions calculator at www.fueleconomy.gov/feg/Find.do?action=bt2.
38The actual calculations were done with unrounded numbers. Using the rounded numbers provided here may
result in a slightly different number due to rounding error.
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The tailpipe plus total upstream CO2 emissions values for PHEVs include the upstream CO2
emissions due to electricity operation and both the tailpipe and upstream CO2 emissions
due to gasoline operation, using the utility factor discussed above to weight the values for
electricity and gasoline operation. The tailpipe plus total upstream CO2 emissions values
for the average car are the average projected real-world model year 2024 car tailpipe CO2
emissions multiplied by 1.25 to account for upstream emissions due to gasoline
production.
The values in columns four through six are tailpipe plus total upstream CO2 emissions. As
mentioned, all of the gasoline and diesel vehicle CO2 emissions data in the rest of this
report refer only to tailpipe emissions and do not reflect the upstream emissions
associated with gasoline or diesel production and distribution. Accordingly, in order to
equitably compare the overall relative impact of BEVs and PHEVs with tailpipe emissions of
petroleum-fueled vehicles, EPA uses the metric "tailpipe plus net upstream emissions" for
BEVs and PHEVs. The net upstream emissions value for a BEV is equal to the total upstream
emissions for the BEV minus the upstream emissions that would be expected from a
comparably sized gasoline vehicle; size is a good first-order measure for utility, and
footprint is the size-based metric used for standards compliance. The net upstream
emissions for PHEVs are equal to the net upstream emissions of the PHEV due to electricity
consumption in electric or blended mode multiplied by the utility factor. The net upstream
emissions for a gasoline vehicle are zero. This approach was adopted for BEV and PHEV
regulatory compliance with the 2012-2016 light-duty vehicle GHG emissions standards for
the production of BEVs and PHEVs beyond a threshold; however, those thresholds were
never exceeded.
For each BEV or PHEV, the upstream emissions for a comparable gasoline vehicle are
determined by first using the footprint-based compliance curves to determine the CO2
compliance target for a vehicle with the same footprint. Since upstream emissions account
for approximately 20% of total C02 emissions for gasoline vehicles, the upstream emissions
for the comparable gasoline vehicle are equal to one-fourth of the tailpipe-only compliance
target.
The final three columns of Table E.4 give the tailpipe plus net upstream C02 values for BEVs
and PHEVs using the same Low, Average, and High electricity upstream CO2 emissions rates
discussed above. These values bracket the possible real-world net CO2 emissions that
would be associated with consumer use of these vehicles. For the Nissan Leaf, these values
are simply the values in columns four through six minus the upstream GHG emissions of a
comparably sized gasoline vehicle. Based on the model year 2024 C02 footprint curve, the
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5-cycle tailpipe GHG emissions for a Leaf-sized gasoline vehicle meeting its compliance
target would be close to 189 grams/mi, with upstream emissions of one-fourth of this
value, or 47 g/mi. The net upstream emissions value for a Leaf is determined by subtracting
this value, 47 g/mi, from the total (tailpipe + total upstream). The result is a range for the
tailpipe plus net upstream value of 33-159 g/mile as shown in Table E.4, with a more likely
sales-weighted value in the 33-81 g/mi range.
For PHEVs, the tailpipe plus net upstream emissions values use the utility factor values
discussed above to weight the individual values for electric operation and gasoline
operation.
Alternative Metrics for BEVs and PHEVs
Determining metrics for BEVs and PHEVs that are meaningful and accurate is challenging.
In particular, vehicles capable of using dual fuels, such as PHEVs, can have complicated
modes of operation that make it difficult to determine meaningful metrics to compare the
vehicle with other vehicles. Here we've discussed several metrics that are used on the
EPA/DOT Fuel Economy and Environment Labels and in a regulatory context, namely mpge,
tailpipe CO2 emissions, and net upstream GHG emissions. There are, however, other ways
that alternative fuel vehicle operation can be quantified.
Other energy metric options that could be considered include: (1) mpge plus net fuel life
cycle energy, which would also reflect differences in upstream energy consumption in
producing the alternative fuel relative to gasoline-from-oil; and (2) miles per gallon of
gasoline, which would only count gasoline use and not other forms of energy. Compared to
mpge, using the mpge plus net fuel life-cycle energy metric would generally result in lower
fuel economy values, and using the miles per gallon of gasoline metric would yield higher
fuel economy values.
Additional Note on PHEV Calculations
Calculating fuel economy and CO2 emission values for PHEVs is a complicated process, as
discussed in this section. The examples given for individual vehicles were based on
calculations behind the EPA/DOT Fuel Economy and Environment Labels. In addition to the
approach used for the labels, there are multiple methods for determining utility factors
depending on the intended use of the value. The standardized utility factor calculations are
defined in the Society of Automobile Engineers (SAE) document SAE J2841.
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The utility factors that are used for fleetwide calculations are somewhat different than
those used to create label values. For label values, multi-day individual utility factors
(MDIUF) are used to incorporate "a driver's day to day variation into the utility calculation."
For fleetwide calculations, fleet utility factors (FUF) are applied to "calculate the expected
fuel and electric consumption of an entire fleet of vehicles." Since the Trends report is
generally a fleetwide analysis, the FUF utility factors were applied, instead of the MDIUF
utility factors, when the data were integrated with the rest of the fleet data. Additionally,
since Trends uses a 43% city / 57% highway weighting for combining real-world fuel
economy and CO2 data, the FUF utility factors created for Trends were based on that
weighting, not on 55% city / 45% highway weighting used on the fuel economy label.
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F. Regulatory Car and Truck Definitions
Under EPA's light-duty GHG regulations and NHTSA's fuel economy standards, new vehicles
are separated into two distinct regulatory classes, passenger cars and light trucks. Each
regulatory class has separate and unique GHG and fuel economy standards. The regulatory
definitions of passenger vehicles (cars) and light trucks (trucks) are located in the U.S.
Department of Transportation's (USDOT) National Highway Traffic Safety Administration's
(NHTSA) CAFE regulations (code of federal regulations: 49 CFR 523.5). NHTSA's regulatory
definitions are based in part on statutory definitions included in the Energy Policy and
Conservation Act of 1975 and the Energy Independence and Security Act of 2007 (codified
at 49 USC 32901). EPA references regulatory definitions for the light-duty GHG program
(code of federal regulations: 40 CFR 86.1818-12).
Figure F.1 shows the generalized decision tree for determining if a vehicle is a car or a truck
under the regulatory definitions, for model year 2012 and later vehicles. First, vehicles that
are above 10,000 gross vehicle weight rating (GVWR), or above 8,500 GVWR and not
considered a MDPV are excluded from EPA's light-duty GHG regulations and CAFE. If the
vehicle is below 8,500 pounds GVWR or an MDPV, then a vehicle can qualify as a light truck
based on the vehicle's functionality or off-road capabilities. Any light-duty vehicles that do
not meet the above functionality or off-road requirements are considered cars for
regulatory purposes.
Note that Figure F.1, and the description of car and truck regulations presented here, are
an overview of the regulatory definitions. They should not be considered a guidance
document or used for compliance purposes. Any compliance related questions as to the
car or truck classifications of specific vehicles should be referred directly to the agencies.
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Figure F.1. Regulatory Car or Truck Flow Chart
Is the vehicle GVWR
more than 10,000 lbs?
NO
Is the vehicle GVWR
more than 8,500 lbs?
NO
YES
YES
Vehicle is excluded
from CAFE and light-
duty GHG regulations
Is it an MDPV
according to EPA
regulations?
NO
Does the vehicle have
3rd row seating?
NO
i
r
Does the vehicle have
4wd?
NO
1
Is the vehicle rated at
more than 6000 pounds
gross vehicle weight?
NO
YES
YES
YES
Vehicle regulatory
classification is Car
0
a
5
YES
Does the vehicle:
Transport more than 10 people?
Provide temporary living quarters?
Transport property on an open bed?
Provide greater cargo-carrying than
passenger-carrying volume?
YES
NO
Does the vehicle permit expanded
cargo capacity through the removal or
stowing of foldable or pivoting seats to
create a flat, leveled cargo surface ?
YES
NO
Does the vehicle have at least 4 of the
following provisions:
Approach angle of & 28 degrees
Breakover angle of a 14 degrees
Departure angle of >20 degrees
Running clearance of a 20 cm
Front/rear axle clearance of a 18 cm
NO
YES
Vehicle regulatory
classification is Truck
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G. Naming Conventions for Electrified
Vehicles
This report identifies several electrification technologies currently being deployed on new
vehicles. In accordance with EPA's light-duty GHG rulemaking39, this report uses the
following conventions to identify specific vehicle technology types and groupings. These
relationships are also depicted in Figure G.1.
Figure G.1. Electrification Groupings of Vehicles
1
ICE
Non-Hybrids
ICE without
Stop/Start
ICE with
Stop/Start
All ICE Vehicles
Electrified
Vehicles
PEVs
BEV
ZEVs
FCEV
The technology categories are:
Internal Combustion Engine (ICE) Vehicle: These vehicles are powered by an
internal combustion engine, in which energy released from the combustion of fuel is
used to power the vehicle. ICE vehicles included in the report include those powered
by gasoline, diesel, and compressed natural gas (CNG).
39 89 FR 27842
G-1
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ICE with Stop/Start: These vehicles have technology that can turn off the internal
combustion engine when the vehicle is stopped and very quickly restart the engine
when the driver releases the brake pedal.
Mild Hybrid Electric Vehicle (MHEV): These vehicles generally have an electric
motor and battery that can assist the engine with moving the vehicle forward at
launch, stop-start systems, and regenerative braking capabilities. However, their
electrical system cannot directly propel the vehicle. For the purposes of this report,
new vehicles with a 48V or less electrical system and have an internal combustion
engine are classified as "mild" hybrids.
Strong Hybrid Electric Vehicle (HEV): These vehicles generally have a larger motor
and battery that can temporarily power the vehicle without engaging the engine and
may be able to capture more energy from regenerative braking than a mild hybrid.
For the purposes of this report, new vehicles equipped with an electrical system
more than 48V and an internal combustion engine are classified as "strong" hybrids.
Plug-in Hybrid Electric Vehicle (PHEV): These vehicles have both a battery that can
be charged from an external electrical source and an internal combustion and
operate on electricity until the battery is depleted or cannot meet driving needs.
Battery Electric Vehicle (BEV): These vehicles operate solely from energy stored in
an onboard battery that can be charged from external electrical source. The energy
from the battery is used to power one or more electric motors to propel the vehicle.
Fuel Cell Electric Vehicle (FCEV): These vehicles use a fuel cell stack to create
electricity from an onboard fuel source (usually hydrogen), which then powers one
or more electric motors to propel the vehicle.
In addition to the specific technology categories above, this report uses the following
technology groupings:
All ICE Vehicles: Any vehicle that includes an internal combustion engine.
ICE Non-Hybrids: Any vehicle that relies on an internal combustion engine but is
not a hybrid vehicle.
Electrified vehicles: Any vehicle with powertrain electrification, including stop/start,
MHEVs, HEVs, PHEVs, and BEVs.
Hybrids: refers collectively to HEVs and MHEVs.
Plug-in Electric Vehicle (PEV): Vehicles that can operate on grid electricity,
including BEVs and PHEVs.
Zero-Emission Vehicle (ZEV): Vehicles with zero tailpipe emissions, including BEVs
and FCEVs
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H. Authors and Acknowledgments
The authors of this year's Trends report are Aaron Hula, Amy Bunker, Tristin Rojeck, Sarah
Harrison, Aaron Sobel, Jonathan Vicente, and Gabrielle Yoes-Favrot, all of whom work for
the EPA Office of Transportation and Air Quality (OTAQ) at the National Vehicle and Fuel
Emissions Laboratory in Ann Arbor, Michigan or at EPA Headquarters in Washington,
District of Columbia. OTAQ colleagues including Karen Danzeisen and Ching-Shih Yang
provided critical access and expertise pertaining to the EV-CIS data that comprise the
Trends database. The authors also want to thankjini Ryan and Londa Scott-Forte of EPA
Office of Public Affairs for greatly improving the design and layout of the report and Eloise
Anagnost of OTAQ. General Dynamics Information Technology (GDIT) under contract to
OTAQ, provided key support for database maintenance, and table and figure generation.
DOT/NHTSA staff reviewed the report and provided helpful comments. Of course, the EPA
authors take full responsibility for the content and any errors.
The authors also want to acknowledge those OTAQ staff that played key roles in creating
and maintaining the Trends database and report since its inception in the early 1970s. Karl
Hellman, who conceived of and developed the initial Trends reports with Thomas Austin in
the early 1970s, was the guiding force behind the Trends report for over 30 years. Dill
Murrell made significant contributions from the late 1970s through the early 1990s, and
Robert Heavenrich was a lead author from the early 1980s through 2006. Jeff Alson
oversaw the continued transformation and modernization of this report from 2007
through 2018. The compliance portion of this report (now section 5) was developed by
Roberts French, and he remained the lead author through the 2019 report. This report has
benefitted immensely from the wealth of insight, creativity, and dedication from each of
these outstanding emeritus authors.
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