The
EPA Automotive
Trends Report
Fuel Economy and Technology since 1975
United States
jbpnl Environmental Protection
^^^¦1 M m Agency
EPA-420-R-26-001 February 2026
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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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Table of Contents
1. Introduction 1
A. What's New This Year 1
B. Manufacturers in this Report 2
C. Fuel Economy Metrics in this Report 3
D. Other Sources of Data 4
2. Fleetwide Trends Overview 5
A. Overall Fuel Economy Trends 5
B. Production Trends 8
C. Manufacturer Fuel Economy 10
3. Vehicle Attributes 15
A. Vehicle Class and Type 15
B. Vehicle Weight 22
C. Vehicle Power 28
D. Vehicle Footprint 34
E. Vehicle Type and Attribute Tradeoffs 39
4. Vehicle Technology 46
A. Vehicle Propulsion 52
B. Vehicle Drivetrain 75
C. Technology Adoption and Comparison 81
Appendices: Methods and Additional Data
A. Sources of Input Data
B. Harmonic Averaging of Fuel Economy Values
C. Fuel Economy Metrics
D. Historical Changes in the Database and Methodology
E. Plug-In Hybrid Fleet Average Data
F. Regulatory Car and Truck Definitions
G. Naming Conventions for Electrified Vehicles
H. Authors and Acknowledgments
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Table of Figures
Figure 2.1. Estimated Real-World Fuel Economy 5
Figure 2.2. Trends in Fuel Economy Since Model Year 1975 7
Figure 2.3. Distribution of New Vehicle Fuel Economy by Model Year 8
Figure 2.4. New Vehicle Production by Model Year 9
Figure 2.5. Changes in Estimated Real-World Fuel Economy by Manufacturer 11
Figure 3.1. Regulatory Classes and Vehicle Types Used in This Report 16
Figure 3.2. Production Share and Estimated Real-World Fuel Economy 17
Figure 3.3. Production Share and Estimated Real-World Fuel Economy 18
Figure 3.4. Vehicle Type Distribution by Manufacturer for Model Year 2024 20
Figure 3.5. Car-Truck Classification of SUVs with Inertia Weights of 4000 Pounds or Less 21
Figure 3.6. Average New Vehicle Weight by Vehicle Type 23
Figure 3.7 Inertia Weight Class Distribution by Model Year 24
Figure 3.8. Average New Vehicle Weight by Vehicle Type and Powertrain 26
Figure 3.9. Relationship Between Inertia Weight and Fuel Economy 27
Figure 3.10. Average New Vehicle Horsepower by Vehicle Type 29
Figure 3.11. Horsepower Distribution by Model Year 30
Figure 3.12. Average New Vehicle Horsepower by Vehicle Type and Powertrain 31
Figure 3.13. Relationship Between Horsepower and Fuel Economy 32
Figure 3.14. Calculated 0-to-60 Time by Vehicle Type 34
Figure 3.15. Footprint by Vehicle Type for Model Years 2008-2025 35
Figure 3.16. Footprint Distribution by Model Year 36
Figure 3.17. Average New Vehicle Footprint by Vehicle Type and Powertrain 37
Figure 3.18. Relationship Between Footprint and Fuel Economy 38
Figure 3.19. Relative Change in Fuel Economy, Weight, Horsepower, and Footprint 40
Figure 4.1. Vehicle Energy Flow for an Internal Combustion Engine Vehicle 46
Figure 4.2. Manufacturer Use of Electrification Technologies for Model Year 2024 49
Figure 4.3. Manufacturer Use of Advanced Technologies for Model Year 2024 51
Figure 4.4. Gasoline Engine Production Share by Number of Cylinders 53
Figure 4.5. Percent Change for Specific Gasoline Non-Hybrid Engine Metrics 55
Figure 4.6. Production Share by Engine Technology 57
Figure 4.7. Engine Metrics for Different Gasoline Technology Packages 58
Figure 4.8. Gasoline Turbo Engine Production Share by Vehicle Type 60
Figure 4.9. Gasoline Turbo Engine Production Share by Number of Cylinders 60
Figure 4.10. Gasoline Non-Hybrid Stop/Start Production Share by Vehicle Type 62
Figure 4.11. Gasoline Non-Hybrid Stop/Start Production Share by Number of Cylinders 62
Figure 4.12. Gasoline Hybrid Engine Production Share by Vehicle Type 64
Figure 4.13. Gasoline Hybrid Engine Production Share by Number of Cylinders 64
Figure 4.14. Gasoline Hybrid Engine Production Share Hybrid Type 65
• •
II
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Figure 4.15. Production Share of BEVs, PHEVs, and FCEVs 67
Figure 4.16. Impact of BEVs and PHEVs 68
Figure 4.17. Battery Electric Vehicle Production Share by Vehicle Type 69
Figure 4.18. Plug-In Hybrid Vehicle Production Share by Vehicle Type 69
Figure 4.19. Charge Depleting Range and Fuel Economy for BEVs and PHEVs 70
Figure 4.20. BEV Energy Consumption by Weight and Vehicle Type 71
Figure 4.21. Diesel Engine Production Share by Vehicle Type 73
Figure 4.22. Diesel Engine Production Share by Number of Cylinders 73
Figure 4.23. Percent Change for Specific Diesel Engine Metrics 74
Figure 4.24. Transmission Production Share 77
Figure 4.25. Transmission By Powertrain Technology, Model Year 2024 78
Figure 4.26. Average Number of Transmission Gears 79
Figure 4.27. Front-, Rear-, and Four-Wheel Drive Production Share 81
Figure 4.28. Industry-Wide Car Technology Penetration after First Significant Use 83
Figure 4.29. Manufacturer Specific Technology Adoption over Time for Key Technologies 85
• • •
III
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Table of Tables
Table 1.1. Model Year 2024 Manufacturers and Makes 2
Table 1.2. Fuel Economy Metrics Used in this Report 4
Table 2.1. Production and Fuel Economy for Model Year 1975-2025 12
Table 2.2. Manufacturers and Vehicles with the Highest Fuel Economy, by Year 13
Table 2.3. Manufacturer Estimated Real-World Fuel Economy for Model Year 2023-2025 14
Table 3.1. Vehicle Attributes by Model Year 41
Table 3.2. Estimated Real-World Fuel Economy by Vehicle Type 42
Table 3.3. Model Year 2024 Vehicle Attributes by Manufacturer 43
Table 3.4. Model Year 2024 Estimated Real-World Fuel Economy by Manufacturer and Vehicle Type
44
Table 3.5. Footprint by Manufacturer for Model Year 2023-2025 (ft2) 45
Table 4.1. Production Share by Drive Technology for Model Year 2024 50
Table 4.2. Production Share by Powertrain 86
Table 4.3. Production Share by Fuel Delivery Method 87
Table 4.4. Production Share by Gasoline Engine Technologies 88
Table 4.5. Production Share by Transmission Technologies 89
Table 4.6. Production Share by Drive Technology 90
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1. Introduction
Since 1975, the EPA has collected data on every new light-duty vehicle model sold in the
United States either from testing performed by the EPA at the National Vehicle and Fuel
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 the EPA criteria pollutant 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 report contains a uniquely comprehensive analysis of the automotive industry
since 1975, based on the EPA's expansive data set, and provides transparency to the public
on data collected by the Agency.
A. What's New This Year
This report is updated each year to reflect the most recent data available to the 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:
• In February 2026, the EPA finalized a rulemaking that eliminated greenhouse gas
standards for light-, medium-, and heavy-duty vehicles and engines. Due to this
action, the EPA is not publishing the portion of this report that previously focused
on manufacturer greenhouse gas regulatory compliance.
• This report includes additional analysis on the impact of battery electric vehicles
(BEVs) and plug-in hybrid vehicles (PHEVs) and their impact on overall vehicle and
technology trends.
• The 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.
1
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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 2024 manufacturer definitions determined by the NHTSA for implementation
of the CAFE program. For simplicity, figures and tables show only the top 14
manufacturers, by production volume. These manufacturers produced at least 175,000
vehicles each in model year 2024 and accounted for more than 97% of all production. Table
1.1 lists all manufacturers that produced vehicles in the U.S. for model year 2024, including
their associated makes. Only vehicle brands produced in model year 2024 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.
Table 1.1. Model Year 2024 Manufacturers and Makes
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
L-
Hyundai
Genesis, Hyundai
V
L-
Kia
Kia
oi 3
W) U
Mazda
Mazda
M—
-I 3
Mercedes
Maybach, Mercedes
£
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
Ineos
Ineos
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When a manufacturer acquires another manufacturer or make, the EPA applies the new
manufacturer relationship to all prior model years throughout this report. This maintains
consistent manufacturer and make relationships over time, which enables better
identification of long-term trends.
C. Fuel Economy Metrics in this Report
All data in this report for model years 1975 through 2024 are final and based on official
data submitted to the EPA and the NHTSA as part of the regulatory process. In some cases,
this report will show data for model year 2025, which are preliminary and are based on
data, including projected production volumes, provided to the 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 future model years, and past performance does not necessarily predict future
industry trends.
The EPA and the NHTSA measure fuel economy for CAFE compliance purposes using the
EPA's city and highway test procedures (the "2-cycle" tests). In addition, the CAFE fleetwide
averages are calculated by weighting the city and highway test results by 55% and 45%,
respectively. These procedures are required by law for CAFE; 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
regulatory requirements.
The data shown throughout this report are estimated real-world data, which supplement
the CAFE compliance data using additional standardized 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. The real-world city and highway results are weighted 43% city and 57%
highway, consistent with more up-to-date 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 still weighted 55% city and 45% highway, like the CAFE
compliance data. Unlike compliance data, which by statute remains unchanged, the
method for calculating real-world data has evolved over time, along with technology and
driving habits.
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Table 1.2. Fuel Economy Metrics Used in this Report
Fuel Economy Data
Category
Current
City/Highway
Purpose Weighting
Current Test
Basis
Compliance
Estimated Real-World
Basis for manufacturer
compliance with standards 55% / 45%
Best estimate of real-world
performance 43%/57%
2-cycle
5-cycle
While compliance data is not currently included in this report, it has been included in past
reports and should not be compared to real-world data. For a more detailed discussion of
the fuel economy data used in this report, including the differences between real-world
and compliance data, see Appendices C and D.
The EPA continues to update detailed data from this report to the EPA Automotive Trends
website. We encourage readers to visit https://www.epa.gov/automotive-trends and
explore the data. The 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. The EPA
supplies the underlying data, much of which can be downloaded at
https://fueleconomy.gov/feg/download.shtml.
In addition, the EPA's Green Vehicle Guide is an accessible, transportation-focused website
that provides information, data, and tools on cleaner options for moving goods and people.
Although this report is based upon data submitted by manufacturers for CAFE compliance,
the focus of the report on real-world fuel economy performance means that it does not
provide data about compliance with the NHTSA's CAFE program. For more information
about the CAFE and manufacturer compliance with the CAFE fuel economy standards, see
the CAFE Public Information Center, which can be accessed at
https://www.nhtsa.gov/corporate-average-fuel-economy/cafe-public-information-center.
D. Other Sources of Data
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2. Fleetwide Trends Overview
The automotive industry continues to make progress towards higher fuel economy in
recent years. This section provides an update on the estimated real-world fuel economy for
the overall fleet, and for manufacturers, based on final model year 2024 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 the EPA began
collecting data in model year 1975.
A. Overall Fuel Economy Trends
In model year 2024, the recent trend of increasing new vehicle real-world fuel economy
continued. The average model year 2024 new vehicle increased fuel economy 0.1 mpg to a
record high 27.2 mpg. Average new vehicle fuel economy has improved 16 out of the last
20 years and has increased 41 % compared to model year 2004. The trends in fuel economy
since 1975 are shown in Figure 2.1.
Figure 2.1. Estimated Real-World Fuel Economy
—i 1 1 1 1 1—
1975 1985 1995 2005 2015 2025
Model Year
Overall fuel economy trends are due to changes in the mix of vehicles produced each year
and evolving vehicle technology. New vehicle production has been trending towards sport
5
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utility vehicles (SUVs) for many years (see section 3) and many new technologies have been
developed and adopted (see section 4). In particular, the production of battery electric
vehicles (BEVs) and plug-in hybrids (PHEVs) have noticeably influenced overall trends in
recent years. Without BEVs and PHEVs, the average new vehicle fuel economy was 1.7 mpg
lower.1,2
Preliminary data suggest that the average new vehicle fuel economy will continue to
increase in model year 2025. The preliminary model year 2025 data are based on
production estimates provided to the 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 these
changes in annual fuel economy tends to be small relative to longer, multi-year trends.
Figure 2.2 shows fleetwide estimated real-world fuel economy for model years 1975-2024.
Over this timeframe, there have been three basic phases: 1) a rapid increase in fuel
economy between 1975 and 1987, 2) a period of slowly decreasing fuel economy through
2004, and 3) increasing fuel economy through the current model year.
1 Throughout this report, the fuel economy of BEVs and PHEVs are measured in terms of miles per gallon of
gasoline equivalent, or mpge. These values are included in fleetwide fuel economy (mpg) values unless noted.
2 The 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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Figure 2.2. Trends in Fuel Economy Since Model Year 1975
Another way to observe fuel economy trends over time is to examine how the distribution
of new vehicle emission rates has changed. Figure 2.3 shows the distribution of real-world
fuel economy for all vehicles produced within each model year. Half of the vehicles
produced each year are clustered within a small band around the median fuel economy, as
shown in blue. The remaining vehicles show a much wider spread, especially in recent
years as the production of electric vehicles with high fuel economy has increased. The
highest fuel economy vehicles have all been hybrids or battery electric vehicles since the
first hybrid was introduced in model year 2000, while the lowest fuel economy vehicles are
generally performance vehicles or large trucks. The introduction of 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 Fuel Economy by Model Year3
150
CD
D.
>*
E
o
c
o
u
LU
T3
O
(0
OL
100
50
Best Vehicle —
Best 5%
Top
25%
Worst Vehicle ¦
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
Model Year
2025
It is important to note that the methodology used in this report for calculating estimated
real-world fuel economy 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.
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 (for example, model year 2024 may cover fall 2023 through fall 2024). However, model
years vary among manufacturers and can occur between January 2 of the preceding
calendar year and the end of the calendar year. Model year production data is the most
3 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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direct way to analyze fuel economy and technology 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 2024. Model year 2024 production was 14,799,239 vehicles.
Figure 2.4. New Vehicle Production by Model Year
20,000 -
O
o
§ 15,000 -
=3
"a
o
CL
as
=3
| 10,000 -
<
5,000 -
9
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C. Manufacturer Fuel Economy
Along with the overall industry, most manufacturers have increased new vehicle 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
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 2.5,13 of the 14 largest manufacturers selling
vehicles in the U.S. increased estimated real-world fuel economy. Toyota had the highest
increase between model years 2019 and 2024, at 3.3 mpg. Toyota was followed by BMW,
which increased fuel economy 2.8 mpg, and Mercedes, which increased 2.4 mpg. Tesla was
the only manufacturer that had decreasing fuel economy between model years 2019 and
2024 due to a large growth in production of car SUVs.
For model year 2024 alone, Tesla's all-electric fleet had the highest fuel economy of all large
manufacturers at 117.1 mpg. Tesla was followed by Honda at 31.0 mpg, Hyundai at 29.8
mpg, and Kia at 29.2 mpg. Stellantis had the lowest new vehicle fuel economy of the large
manufacturers in model year 2024 at 22.8 mpg, followed by GM at 22.9 mpg, and Ford at
23.4 mpg.
Increasing penetration of BEVs and PHEVs impacted fuel economy improvements between
model years 2019 and 2024 for nearly all manufacturers, but to different extents. Figure 2.5
also shows the results for each manufacturer excluding BEVs and PHEVs. The largest
impact of excluding these vehicles is for BMW, which achieved a 2.8 mpg increase in fuel
economy overall, but had a small decrease in fuel economy when excluding BEVs and
PHEVs. Seven manufacturers that had overall fuel economy improvements show
decreasing fuel economy between model year 2019 and 2024 when BEVs and PHEVs are
excluded. Conversely, manufacturers such as Toyota show a large increase in fuel economy
between 2019 and 2024 with or without BEVs and PHEVs. For Toyota, this is due in part to
increasing production of strong hybrid vehicles.
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Figure 2.5. Changes in Estimated Real-World Fuel Economy by Manufacturer
All Vehicles
Without BEVs/PHEVs
Tesla
Honda
Hyundai
Kia
Toyota
Nissan
BMW
Subaru
Mazda
VW
Mercedes
Ford
GM
Stellantis
All Manufacturers
100
105
110
117.1^118.0
115 120
160
28.9 ^31.0
28.5—^29.8
>8.1->29.2
25
27.0
~29.0
/
!8.>28.7
>28.0
i.5
ti
27.
>6>2(
00 7
22.5>23.4
22. >22.9
21.2—~22.8
24.<
27.2
165
110
115
25
23. >2
22. >22.6
22."K22.3
21.>21.3
24.($-#*125.6
28.8-^30.1
27.9<28.2
27.3<27.8
>28.4
P6.7 ^28.5
120
20
24
28
32
20
24
28
32
Fuel Economy (MPG)
11
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Table 2.1. Production and Fuel Economy for Model Year 1975-2025
Production
Real-World
Production
Real-World
Model Year
(000)
FE(MPG)
Model Year
(000)
FE(MPG)
1975
10,224
13.1
2001
15,605
19.6
1976
12,334
14.2
2002
16,115
19.5
1977
14,123
15.1
2003
15,773
19.6
1978
14,448
15.8
2004
15,709
19.3
1979
13,882
15.9
2005
15,892
19.9
1980
11,306
19.2
2006
15,104
20.1
1981
10,554
20.5
2007
15,276
20.6
1982
9,732
21.1
2008
13,898
21.0
1983
10,302
21.0
2009
9,316
22.4
1984
14,020
21.0
2010
11,116
22.6
1985
14,460
21.3
2011
12,018
22.3
1986
15,365
21.8
2012
13,449
23.6
1987
14,865
22.0
2013
15,198
24.2
1988
15,295
21.9
2014
15,512
24.1
1989
14,453
21.4
2015
16,739
24.6
1990
12,615
21.2
2016
16,278
24.7
1991
12,573
21.3
2017
17,016
24.9
1992
12,172
20.8
2018
16,260
25.1
1993
13,211
20.9
2019
16,139
24.9
1994
14,125
20.4
2020
13,721
25.4
1995
15,145
20.5
2021
13,812
25.4
1996
13,144
20.4
2022
12,860
26.0
1997
14,458
20.2
2023
14,199
27.1
1998
14,456
20.1
2024
14,799
27.2
1999
15,215
19.7
2025 (prelim)
28.1
2000
16,571
19.8
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
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Table 2.2. Manufacturers and Vehicles with the Highest Fuel Economy, by Year
Overall Vehicle with Gasoline (Non-Hybrid) Vehicle
Manufacturer
Manufacturer
Highest Fuel Economy5
with Highest Fuel Economy
with Highest
with Lowest
Real-
Real-
Fuel Economy4
Fuel Economy
World FE
Engine
World FE
Model Year
(mpg)
(mpg)
Vehicle
(mpg)
Type6
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
Tesla
Stellantis
Hyundai loniq 6
137.0
BEV
M
tsubishi M
rage
41.6
2025 (prelim)
Tesla
Stellantis
Lucid Air Pure RWD
144.8
BEV
Honda Civic
36.6
4 Manufacturers below the 175,000 threshold for "large" manufacturers are excluded in years they did not meet the threshold.
5 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.
6 FCEV= Fuel Cell Electric Vehicle. For more information on engine types, see section 4.
13
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Table 2.3. Manufacturer Estimated Real-World Fuel Economy for Model Year 2023-2025
MY 2023
MY 2025
Final
MY 2024 Final
Preliminary
FE Change
Real-World
Real-World
from
Real-World
FE
FE
MY 2022
FE
Manufacturer
(mpg)
(mpg)
(mpg)
(mpg)
Tesla
120.6
117.1
-3.4
119.4
Honda
28.3
31.0
2.7
29.6
Hyundai
29.8
29.8
0.0
30.4
Kia
30.4
29.2
-1.1
29.2
BMW
27.6
29.0
1.3
31.1
Nissan
28.9
29.0
0.2
29.0
Toyota
27.5
29.0
1.6
30.5
Subaru
28.4
28.7
0.4
28.7
Mazda
27.6
28.0
0.4
28.1
VW
27.0
26.5
-0.5
29.1
Mercedes
27.5
26.1
-1.3
28.1
Ford
23.2
23.4
0.2
24.4
GM
22.4
22.9
0.6
24.1
Stellantis
21.8
22.8
0.9
22.8
All Manufacturers
27.1
27.2
0.1
28.1
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
14
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3. Vehicle Attributes
Vehicle fuel economy is 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 than other comparable vehicles. This section
focuses on several key vehicle design attributes that impact 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
NHTSA regulations, new vehicles are separated into two distinct regulatory classes,
passenger vehicles (i.e., cars) and non-passenger vehicles (i.e., light trucks), and each
vehicle class is subject to separate fuel economy standards.7 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 rating (GVWR) of
more than 6,000 pounds or have four-wheel drive and meet various off-highway
requirements, such as ground clearance, can also qualify as non-passenger vehicles.8
Vehicles that do not meet these requirements are considered cars. For more information
on vehicle 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 NHTSA 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
7 Passenger vehicles (i.e., cars) and non-passenger vehicles (i.e., light trucks) are defined by regulation in the
Department of Transportation's 49 CFR 523.4-523.5.
8 Gross vehicle weight rating (GVWR) is the combined weight of the vehicle, passengers, and cargo of a fully
loaded vehicle.
15
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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 NHTSA 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 NHTSA
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 increasing fuel economy.
Figure 3.1. Regulatory Classes and Vehicle Types Used in This Report
Regulatory Class Vehicle Type
16
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Fuel Economy 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
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 less than 25% in model year 2024, sedans/wagons now hold less than a
third of the market share they held in model year 1975. The production share of pickups
has fluctuated over time, peaking at 19% in 1994, then falling to 10% in 2012, and hovering
around 15% in recent years. 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.
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 60% of all new vehicles produced. In model
year 2024, truck SUVs increased market share to almost 50% of all new vehicle production,
while the production share of all other vehicle types fell. The projected 2025 data shows a
vehicle type distribution that is similar to model year 2024.
Figure 3.2. Production Share and Estimated Real-World Fuel Economy
Model Year
17
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The truck regulatory class (including pickups, minivan/vans, and truck SUVs) increased
production share in model year 2024 to an all-time high of 66%. Trucks are projected to
maintain about the same production share in model year 2025. In Figure 3.2, the dashed
line between the car SUVs and truck SUVs shows the split in car and truck regulatory class.
Figure 3.3. Production Share and Estimated Real-World Fuel Economy
40
30
20
10
40
o
30
n
20
1"
10
o
c
40
o
o
LU
30
-------
now achieve fuel economy more than double what they achieved in 1975. In the
preliminary model year 2025 data (shown as a dot on Figure 3.3), all vehicle types, except
car SUVs, are expected to increase fuel economy from model year 2024.
Overall fuel economy 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 had the highest fuel economy, so the market shifts
toward other vehicle types with lower fuel economy offset some of the fleetwide benefits
that otherwise would have been achieved from the increases within each vehicle type.
However, the growth of electric vehicles is changing the relationship between vehicle types
and overall average new vehicle fuel economy.
Within each vehicle type, BEVs and PHEVs increased average fuel economy to varying
degrees. In model year 2024, 30% of car SUVs were BEVs, and an additional 3% were
PHEVs. This led to a 9.0 mpg increase in fuel economy for car SUVs, compared to model
year 2023. Sedan/wagon fuel economy was 1.8 mpg higher due to 7% BEVs and 1 % PHEVs,
and truck SUV fuel economy was 1.0 mpg higher due to 4% BEVs and 4% PHEVs.
Minivan/van fuel economy was 0.6 mpg higher due to 5% PHEVs (and no BEVs), while
pickup fuel economy was 0.3 mpg higher, due to 2% BEVs (and no PHEVs).
The model year 2024 production breakdown by vehicle type for each manufacturer is
shown in Figure 3.4. There are clear variations in production distribution by manufacturer.
Nissan had the highest production of sedan/wagons at 53%, Tesla had the highest
percentage of car SUVs at 61 %, Mazda had the highest percentage of truck SUVs at 90%,
Ford had the highest percentage of pickups at 42%, and Stellantis had the highest
percentage of minivan/vans at 9%.
19
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Figure 3.4. Vehicle Type Distribution by Manufacturer for Model Year 2024
Higher average Fuel Economy
100%
75%
0
!
TO
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(J)
c
o
2 50%
o
T3
O
25%
0%
<*// W//^/ */ *
Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
| Pickup
Stellantis, Mercedes, Hyundai, Kia, and Toyota all increased production of truck SUVs by
more than five percentage points compared to model year 2023, mostly at the expense of
sedan/wagons. Nissan was the only company with a significant shift towards
sedan/wagons, away from car and truck SUVs. GM decreased their truck SUV production
share by 11 percentage points, while increasing their production share of pickups. All other
vehicle type production shifts within each manufacturer were less than 10 percentage
points.
20
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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 60% of all vehicles produced (see Figure 3.2). This includes both
the car SUV 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 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 3.5 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 77% in model year 2024,
which is the highest percentage of production since at least model year 2000. Model year
2025 data is projected to have a slightly lower ratio of truck SUVs.
Figure 3.5. Car-Truck Classification of SUVs with Inertia Weights of 4000
Pounds or Less
100%
a; 75%
05
-C
co
.1 50%
=3
"a
o
25%
0%
2000 2005 2010 2015 2020 2025
Model Year
21
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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 factors being equal, will require more energy
to move. For vehicles with an internal combustion engine (ICE), this higher energy
requirement generally results in decreased fuel economy. Among BEVs, increased weight
will likely decrease the overall efficiency of the vehicle, measured either in kilowatt-hours
per 100 miles or mpge. Due to the weight of battery packs, electric vehicles are likely to
weigh more than comparable ICE 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 weights plus 300
pounds.9 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 3.6 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 2024 was
about 6% above 2004 and is currently just below the highest point on record, at 4,354
pounds. Preliminary model year 2025 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
2024, the difference between the heaviest and lightest vehicle types was about 1,700
pounds, or about 39% of the average new vehicle weight. In 1975, the average new
sedan/wagon outweighed the average new pickup by 46 pounds, but the different weight
trends over time for each of these vehicle types led to a very different result in model year
9 Vehicle curb weight is the weight of an empty, unloaded vehicle.
22
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2024, with the average new pickup outweighing the average new sedan/wagon by about
1,700 pounds. Pickups are below their model year2014 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 BEVs,
appears to be pushing vehicle weights back up.
Figure 3.6. 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 3.7 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 below 2,750 pounds to 5,500 pounds. In the early 1980s, the largest
vehicles disappeared from the market, and light cars below 2,750 pounds inertia weight
briefly captured more than 25% of the market. Since then, cars in the below 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.
23
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Figure 3.7 Inertia Weight Class Distribution by Model Year
Weight
¦
<2750
2750
3000
3500
4000
4500
¦
5000
¦
5500
¦
6000
¦
>6000
100%
75%
0
1
ro
_£Z
CO
O 50%
o
=3
"O
o
25%
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 ICE vehicle.
Figure 3.8 shows the average weight, by vehicle type, of ICE non-hybrid vehicles10
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 non-hybrid counterparts. BEVs and PHEVs
10 See appendix G for an explanation of groupings this report uses to evaluate groupings of electrification
technologies.
24
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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 3.6. This trend has been driven by many factors, including market shifts between
vehicle types. The weight difference between ICE non-hybrid vehicles and BEV/PHEV
vehicles shown for most model year 2024 vehicle types in Figure 3.8 is less than the
difference in weight between ICE non-hybrid sedan/wagons and ICE non-hybrid truck SUVs.
Overall vehicle production has been moving away from sedan/wagons towards truck SUVs
for decades, as shown in Figure 3.2. This market shift has 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 3.8, 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 3.8.
25
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Figure 3.8. Average New Vehicle Weight by Vehicle Type and Powertrain
(/)
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I
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7000
6000
5000
4000
3000
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 Fuel Economy
Heavier vehicles require more energy to move than lower-weight vehicles and, if all other
factors are the same, will have lower fuel economy. Figure 3.9 shows estimated real-world
fuel economy as a function of vehicle inertia weight for several model year 2024
technologies. Increased weight correlates to lower fuel economy for ICE and hybrid
technologies and may also correlate for PHEVs. For BEVs, increasing BEV weight likely
correlates to reduced vehicle efficiency, as measured in mpge. Limited data did not allow
for trendlines in Figure 3.9 for PHEV and BEV data.
26
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Figure 3.9. Relationship Between Inertia Weight and Fuel Economy11
Gasoline ICE Gasoline ICE + Stop/Start
MHEV
O
150
100
50
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HEV
PHEV
-------
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 2024 produced 88%
more power than an average new vehicle in model year 1975, and 153% more power than
an average new vehicle in model year 1981. The average new vehicle horsepower is 258 hp
in model year 2024, which is down 10 hp from the previous model year. The preliminary
value for model year 2025 is 264 hp.
Electric motors provide power differently than ICEs. For example, ICEs need to achieve a
high rotation speed (rotations per minute, or RPM) before they can achieve maximum
horsepower. Conversely, 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 ICE, 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 3.10. Horsepower for sedan/wagons increased 54% between model year
1975 and 2024,118% for car SUVs, 77% for truck SUVs, 82% for minivan/vans, and 138% 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.
28
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Figure 3.10. Average New
88% I
Since MY 1975
118% I
Since MY 1975
Truck SUV
Minivan/Van
Pickup
77% I
Since MY 1975
82% I
Since MY 1975
138% I
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 3.11. While few new vehicles in the early 1980s had greater
than 200 hp, the average vehicle in model year 2024 had 258 hp. In addition, vehicles with
more than 250 hp make up 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 2025, with about 8% of vehicles projected to reach 400 hp or higher.
Vehicle Horsepower by Vehicle Type
Sedan/Wagon Car SUV
54% I
Since MY 1975
29
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Figure 3.11. Horsepower Distribution by Model Year
100%-
75% -|
0
to
_c
CO
.2 50%
"G
3
T3
O
25% -
0%-
1975 1985 1995 2005
Model Year
2015
2025
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 ICE, to move the vehicle.
Electric motors have the advantage of having maximum torque available from a standstill
and can be used to enhance vehicle horsepower. Figure 3.12 shows the average
horsepower, by vehicle type, of ICE non-hybrid vehicles compared to PHEVs and BEVs. For
each of the four most popular vehicle types, PHEVs and BEVs have higher horsepower than
their ICE non-hybrid 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 are increasing the overall
horsepower within each vehicle type (except for minivan/vans) with the overall impact
dependent on the uptake of PHEVs and BEVs within each vehicle type.
30
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Figure 3.12. Average New Vehicle Horsepower by Vehicle Type and Powertrain
500
400
300
200
100
0
=0
¦ /
/ /
/ /
/ /
v 0
—i 1 1 1 1—
Sedan/Wagon Car Truck Minivan/Van Pickup
SUV SUV
Vehicle Type
Fleet Average
Gasoline ICE
BEV/PHEV
Vehicle Power and Fuel Economy
As with weight, higher horsepower vehicles are generally less efficient, if all other factors
are held the same. However, the relationship between vehicle power and fuel economy has
become more complex as new technologies and vehicles have emerged in the
marketplace. Figure 3.13 shows estimated real-world fuel economy as a function of vehicle
horsepower for several model year 2024 technologies. Increased horsepower correlates to
lower fuel economy for ICE, hybrid, and PHEV vehicles. However, the relationship between
increasing BEV horsepower and vehicle efficiency, as measured in mpge, is less clear. There
was no clear trendline in Figure 3.13 for BEV data.
31
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Figure 3.13. Relationship Between Horsepower and Fuel Economy
150 -
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Horsepower
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 the
EPA but are calculated for most vehicles using vehicle attributes and calculation methods
developed by MacKenzie and Heywood (2012).12
12 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
Gasoline ICE Gasoline ICE + Stop/Start
MHEV
HEV
PHEV
**
BEV
32
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The relationship between power and acceleration is different for BEVs than for vehicles
with ICEs. Electric motors generally have maximum torque available from a standstill, which
is not true for ICEs. 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 increase 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 3.14
shows the average new vehicle 0-to-60 time since model year 1978. The average new
vehicle in model year 2024 had a 0-to-60 time of 7.5 seconds, which is close to 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 2025 is projected to decrease
slightly to 7.3 seconds. The long-term downward trend in 0-to-60 times is consistent across
all vehicle types. Increased BEV production could continue, and perhaps increase, the trend
towards lower 0-to-60 acceleration times.
Board, Paper NO 12-1475, TRB 91st Annual Meeting, Washington, DC, January 2012.
https://doi.Org/10.1016/j.tra.2015.12.001
33
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Figure 3.14. Calculated 0-to-60 Time by Vehicle Type
18
15
12
9
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c 6
o
15
12
9
6
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 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 the EPA has less confidence in the precision of
these data than that of formal CAFE 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 the 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 2024. The
EPA projects footprint data for the preliminary model year 2025 fleet based on footprint
values from the previous model year and, for new vehicle designs, publicly available data.
ALL
-4
IF>%
\
Since MY
1978
Truck SUV
-43%
Since MY
4
1978
t r
Sedan / Wagon
-43% T
Since MY 1978
Car SUV
-46%
I
Since MY 1978
Pickup
-50%
1
Since MY ia/o
•
34
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Vehicle Footprint by Vehicle Type
Figure 3.15 shows overall new vehicle and vehicle type footprint data since model year
2008. Between model year 2008 and 2024, the overall average footprint increased 5.4%,
from 48.9 to 51.5 square feet. All five vehicle types have increased average footprint since
model year 2008, with truck SUVs increasing 3.3%, sedan wagons increasing 3.4%, car SUVs
increasing 3.7%, pickups increasing 3.9%, and minivans/vans increasing 5.2%. The industry
wide increase in footprint is larger than the increase within any individual vehicle type, due
to both the trends within each vehicle type and the changing mix of vehicles over time as
the market has shifted towards larger vehicles.
Figure 3.15. Footprint by Vehicle Type for Model Years 2008-2025
70-
60-
O"
CO
o
o
50-
40-
Pickup
Minivan/Van
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 3.16, 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 2025 suggest that overall average footprint will increase
slightly to 51.8 square feet.
35
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Figure 3.16. Footprint Distribution by Model Year
100% -
75% -
CD
(6
_c
co
O 50% H
H—'
o
=3
"O
o
25% -
0% -
2008 2010 2012 2014 2016 2018 2020 2022 2024
Model Year
Footprint
>65
^ 60-65
55-60
H 50-55
45-50
40-45
<40
Vehicle Footprint and Technology
Figure 3.17 shows the average footprint, by vehicle type, of ICE non-hybrid vehicles
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.
36
-------
Figure 3.17. Average New Vehicle Footprint by Vehicle Type and Powertrain
/ry/
/ v
/ v
/ y
/ y
/ y
/ y
/ y
y y
Sedan/Wagon Car
SUV
Truck Minivan/Van Pickup
SUV
Vehicle Type
Fleet Average
Gasoline ICE
BEV/PHEV
Vehicle Footprint and Fuel Economy
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
decrease fuel economy. Figure 3.18 shows estimated real-world fuel economy as a
function of vehicle footprint for several model year 2024 technologies. Increased footprint
correlates to lower fuel economy 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 measured in mpge. There was no clear trendline in Figure 3.18 for PHEV and
BEV data.
37
-------
Figure 3.18. Relationship Between Footprint and Fuel Economy
o
Q.
>
E
o
c
o
o
LD
"a)
3
CD
©
Cd
Gasoline ICE Gasoline ICE + Stop/Start
150
100
50
150
100
50
HEV
40 50 60 70~
MHEV
PHEV
BEV
40 50 60 70
Footprint (sq ft)
40 50 60 70
38
-------
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. Since model year 2004, average new vehicle fuel economy
has increased 41%, horsepower increased 23%, and weight increased 6%. Footprint has
increased 5% since the EPA began tracking it in model year 2008. Fuel economy, weight,
horsepower, and footprint are all projected to increase in model year 2025, as shown in
Figure 3.19.
In model year 2024, compared to 2023, fuel economy increased while average new vehicle
weight, horsepower, and footprint all fell slightly (less than 5%). This is due in part to lower
production of BEVs in model year 2024, as BEVs fell from 10% to 7% of all new vehicles, and
because BEVs are on average more efficient, powerful, and heavier than comparable
vehicles. Without BEVs and PHEVS, the average model year 2024 new vehicle fuel economy
was lower by 1.7 mpg, power was lower by 13 hp, weight was lower by 72 pounds, and
footprint was slightly lower by 0.1 square feet.
The changes within each of these metrics are 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 benefits that otherwise would have been achieved through
additional technology.
Vehicle fuel economy is clearly related to vehicle attributes investigated in this section,
namely weight, horsepower, and footprint. Future trends in fuel economy will be
dependent, at least in part, on design choices related to these attributes.
39
-------
Figure 3.19. Relative Change in Fuel Economy, Weight, Horsepower, and
Footprint
125%-
100%
75%-
LO
h-
05
(D
o
50%-
a;
O)
c
(C
O 25% =
0% =
-25%-
«
Real-World Fuel
Economv
D • O
1
Horsepower
Weight
oo
o
o
CM
-------
Table 3.1. Vehicle Attributes by Model Year
Model Year
Real-World
FE
(mpg)
Weight
(lbs)
Horsepower
(HP)
0 to 60
(s)
Footprint
(ft2)
Car
Production
Share
Truck
Production
Share
1975
13.1
4,060
137
-
-
80.7%
19.3%
1980
19.2
3,228
104
15.6
-
83.5%
16.5%
1985
21.3
3,271
114
14.1
-
75.2%
24.8%
1990
21.2
3,426
135
11.5
-
70.4%
29.6%
1995
20.5
3,613
158
10.1
-
63.5%
36.5%
2000
19.8
3,821
181
9.8
-
58.8%
41.2%
2005
19.9
4,059
209
9.0
-
55.6%
44.4%
2010
22.6
4,001
214
8.8
48.5
62.8%
37.2%
2011
22.3
4,126
230
8.5
49.5
57.8%
42.2%
2012
23.6
3,979
222
8.5
48.8
64.4%
35.6%
2013
24.2
4,003
226
8.4
49.1
64.1%
35.9%
2014
24.1
4,060
230
8.3
49.7
59.3%
40.7%
2015
24.6
4,035
229
8.3
49.4
57.4%
42.6%
2016
24.7
4,035
230
8.3
49.5
55.3%
44.7%
2017
24.9
4,093
234
8.2
49.8
52.6%
47.4%
2018
25.1
4,137
241
8.0
50.4
48.0%
52.0%
2019
24.9
4,156
245
7.9
50.8
44.4%
55.6%
2020
25.4
4,166
246
7.8
50.9
43.9%
56.1%
2021
25.4
4,289
254
7.7
51.5
37.1%
62.9%
2022
26.0
4,303
260
7.6
51.6
36.9%
63.1%
2023
27.1
4,372
268
7.3
51.8
37.5%
62.5%
2024
27.2
4,354
258
7.5
51.5
34.3%
65.7%
2025 (prelim)
28.1
4,441
264
7.3
51.8
34.7%
65.3%
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
41
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Table 3.2. Estimated Real-World Fuel Economy by Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
Pickup
Model Year
Prod
Share
Real-
World FE
(mpg)
Prod
Share
Real-
World FE
(mpg)
Prod
Share
Real-
World FE
(mpg)
Prod
Share
Real-
World FE
(mpg)
Real-
Prod World FE
Share (mpg)
1975
80.6%
13.5
0.1%
11.1
1.7%
11.0
4.5%
11.1
13.1%
11.9
1980
83.5%
20.0
0.0%
14.6
1.6%
13.2
2.1%
14.1
12.7%
16.5
1985
74.6%
23.0
0.6%
20.1
4.5%
16.5
5.9%
16.5
14.4%
18.2
1990
69.8%
23.3
0.5%
18.8
5.1%
16.4
10.0%
17.8
14.5%
17.4
1995
62.0%
23.4
1.5%
17.8
10.5%
16.0
11.0%
18.1
15.0%
16.9
2000
55.1%
22.9
3.7%
17.9
15.2%
16.0
10.2%
18.6
15.8%
16.7
2005
50.5%
23.5
5.1%
20.2
20.6%
16.7
9.3%
19.3
14.5%
15.8
2010
54.5%
26.2
8.2%
23.0
20.7%
19.7
5.0%
20.1
11.5%
16.9
2011
47.8%
25.8
10.0%
23.5
25.5%
19.8
4.3%
20.9
12.3%
17.2
2012
55.0%
27.6
9.4%
23.3
20.6%
20.0
4.9%
21.3
10.1%
17.2
2013
54.1%
28.4
10.0%
24.3
21.8%
20.8
3.8%
21.1
10.4%
17.5
2014
49.2%
28.4
10.1%
24.4
23.9%
21.6
4.3%
21.3
12.4%
18.0
2015
47.2%
29.0
10.2%
25.1
28.1%
21.9
3.9%
21.8
10.7%
18.8
2016
43.8%
29.2
11.5%
26.2
29.1%
22.2
3.9%
21.7
11.7%
18.9
2017
41.0%
30.2
11.6%
26.1
31.7%
22.3
3.6%
22.2
12.1%
18.9
2018
36.7%
30.8
11.3%
27.4
35.0%
23.1
3.1%
22.8
13.9%
19.1
2019
32.7%
30.9
11.7%
27.5
36.5%
23.5
3.4%
22.4
15.6%
19.0
2020
30.9%
31.7
13.0%
28.4
38.7%
23.8
2.9%
23.4
14.4%
19.2
2021
25.7%
32.2
11.4%
31.0
44.7%
24.1
2.2%
27.3
16.1%
19.3
2022
26.5%
33.2
10.4%
33.4
43.8%
24.2
2.9%
26.0
16.4%
20.0
2023
25.0%
34.1
12.5%
40.5
45.4%
24.7
2.5%
25.9
14.7%
20.5
2024
23.7%
33.5
10.6%
39.2
49.6%
25.7
2.0%
26.1
14.1%
20.5
2025 (prelim)
23.1%
36.2
11.6%
37.6
48.3%
26.3
2.3%
28.2
14.8%
21.3
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
42
-------
Table 3.3. Model Year 2024 Vehicle Attributes by Manufacturer
Manufacturer
Real-World
FE
(mpg)
Weight
(lbs)
Horsepower
(HP)
0-to-60
(s)
Footprint
(ft2)
BMW
29.0
4679
345
5.9
50.6
Ford
23.4
4782
303
6.8
56.5
GM
22.9
4685
277
7.6
56.2
Honda
31.0
3903
202
7.9
48.7
Hyundai
29.8
3923
214
7.9
49.2
Kia
29.2
3899
212
8.1
49.2
Mazda
28.0
4043
213
8.6
48.4
Mercedes
26.1
5082
332
5.7
52.5
Nissan
29.0
3993
217
8.4
48.6
Stellantis
22.8
4955
324
6.7
54.9
Subaru
28.7
3836
191
9.1
45.8
Tesla
117.1
4410
420
5.6
50.8
Toyota
29.0
4274
231
7.5
50.8
VW
26.5
4273
260
7.2
48.0
Other
28.0
4499
293
7.6
48.8
All Manufacturers
27.2
4354
258
7.5
51.5
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
-------
Table 3.4. Model Year 2024 Estimated Real-World Fuel Economy by Manufacturer and Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
Pickup
Real-
Real-
Real-
Real-
Real-
Prod
World FE
Prod
World FE
Prod
World FE
Prod
World FE
Prod World FE
Manufacturer
Share
(mpg)
Share
(mpg)
Share
(mpg)
Share
(mpg)
Share
(mpg)
BMW
42.9%
33.3
6.3%
26.0
50.8%
26.5
-
-
-
-
Ford
4.4%
21.9
6.9%
44.3
46.8%
22.6
-
-
41.8%
22.8
GM
18.6%
28.7
11.0%
30.3
37.6%
23.2
-
-
32.8%
18.9
Honda
46.0%
33.6
7.4%
34.8
38.2%
30.1
5.8%
23.6
2.5%
20.9
Hyundai
23.4%
35.9
25.0%
35.9
51.6%
25.7
-
-
-
-
Kia
26.9%
32.8
17.9%
41.5
48.0%
25.9
7.1%
22.9
-
-
Mazda
10.0%
31.1
-
-
90.0%
27.7
-
-
-
-
Mercedes
32.1%
30.8
11.1%
35.3
56.8%
23
-
-
-
-
Nissan
53.0%
34.3
8.0%
32.8
28.8%
25.1
-
-
10.2%
20.1
Stellantis
1.1%
39.1
3.2%
46.5
69.8%
22.7
9.4%
25.3
16.5%
19.3
Subaru
12.8%
28.7
-
-
87.2%
28.7
-
-
-
-
Tesla
30.0%
125.5
60.9%
113.7
9.1%
114.8
-
-
-
-
Toyota
27.0%
36
9.5%
31.5
45.4%
28.6
2.9%
35.6
15.3%
21.1
VW
23.9%
28
10.6%
37.3
65.5%
24.9
-
-
-
-
Other
21.9%
37.2
1.9%
68.0
74.7%
25.6
0.5%
27.3
1.0%
71.7
All Manufacturers
23.7%
33.5
10.6%
39.2
49.6%
25.7
2.0%
26.1
14.1%
20.5
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
44
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Table 3.5. Footprint by Manufacturer for Model Year 2023-2025 (ft2)
Manufacturer
Final MY 2023
Final MY 2024
Preliminary MY2025
Car
Truck
All
Car
Truck
All
Car
Truck
All
BMW
48.6
52.0
50.2
48.8
52.3
50.6
48.3
51.9
50.2
Ford
49.2
59.2
58.2
48.2
57.6
56.5
48.4
58.3
57.1
GM
46.3
59.0
55.7
46.6
60.2
56.2
47.0
60.4
56.2
Honda
46.9
51.9
49.4
46.8
50.9
48.7
46.7
51.5
49.2
Hyundai
47.6
50.3
48.7
48.1
50.3
49.2
48.4
50.2
49.3
Kia
46.2
50.0
47.9
46.5
51.4
49.2
46.7
51.1
49.0
Mazda
44.0
47.0
46.7
44.5
48.8
48.4
44.2
48.6
48.3
Mercedes
50.7
53.9
52.3
50.8
53.8
52.5
50.5
53.2
51.8
Nissan
46.6
50.6
48.4
46.3
52.2
48.6
46.6
50.7
48.4
Stellantis
52.8
56.6
56.0
46.4
55.2
54.9
48.1
58.0
57.5
Subaru
45.0
46.2
46.0
45.1
46.0
45.8
45.2
45.9
45.8
Tesla
50.7
51.5
50.7
50.8
51.4
50.8
50.2
66.1
50.6
Toyota
46.9
52.6
50.4
46.6
53.2
50.8
46.9
54.1
51.2
VW
46.5
50.3
48.8
45.7
49.2
48.0
46.0
50.0
48.8
Other
47.6
51.6
50.8
43.5
50.5
48.8
50.8
53.2
52.9
All Manufacturers
47.7
54.2
51.8
47.1
53.8
51.5
47.4
54.2
51.8
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends
45
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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 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 fuel economy.
Vehicle Architecture
All vehicles use some type of engine or electric 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 ICE is shown in Figure 4.1. ICEs
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 decrease fuel economy.
Figure 4.1. Vehicle Energy Flow for an Internal Combustion Engine Vehicle
*
Tires
Engine
I
Transmission
I
Driveline
* *
46
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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 low-
voltage battery, which enables the vehicle to turn off the engine at idle to save fuel. Hybrid
vehicles use a larger, higher-voltage battery to recapture braking energy and provide
traction power when necessary, allowing for a smaller, more efficiently operated engine.
Hybrids can be separated into "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. PHEVs 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. HEVs and PHEVs often
have much more complicated architectures that allow for complex energy optimization
strategies that ultimately improve some combination of vehicle fuel economy and vehicle
performance. These vehicles use a combination of an engine and one or more electric
motors to power the wheels, and recapture braking energy.
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
powertrain architecture layouts, as vehicles with one electric motor can be directly
connected to the driveline without a traditional transmission.13 However, some
manufacturers are producing electric vehicles with 2-speed transmissions, and others have
developed vehicles with two or more electric 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 an electric motor, have also been produced in recent years. These vehicles are
13 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)
47
-------
included in the data for this report but generally have not been produced in large
volumes.14
Overall Industry Trends
Innovation in the automobile industry has led to a wide array of technologies available to
manufacturers to achieve fuel economy and performance goals and meet regulatory
requirements. Figure 4.3 illustrates manufacturer-specific technology usage for model year
2024 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 4.3 are being used by manufacturers, in part, to 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 2024, gasoline vehicles with stop/start,
MHEVs, HEVs, and PHEVs 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 ICEs, 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.
14 Vehicles converted to an alternative fuel in the aftermarket are not included in this data.
48
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Figure 4.2. Manufacturer Use of Electrification Technologies for Model Year 2024
wvvj/ ^
2010
2015 2020
Model Year
2025
Diesel ICE
Gasoline ICE
Gasoline ICEl
+ Stop/Start
MHEV
HEV
PHEV
BEV
Other
49
-------
Table 4.1. Production Share by Drive Technology for Model Year 2024
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
0.7%
17.2%
57.6%
5.3%
9.5%
2.5%
7.2%
0.0%
100.0%
Stop/Start
100.0%
-
100.0%
93.2%
100.0%
86.7%
-
-
74.9%
GDI
-
33.3%
71.8%
73.7%
35.5%
74.7%
-
-
56.2%
GDPI
-
33.2%
19.7%
13.4%
53.9%
16.5%
-
-
23.3%
Turbo
100.0%
20.6%
57.1%
75.3%
23.3%
67.7%
-
-
45.1%
7+ Gears
100.0%
33.8%
71.1%
100.0%
12.9%
61.5%
-
-
55.6%
CVT
-
45.8%
22.5%
-
75.5%
23.8%
-
100%
28.6%
Average Fuel
Economy
23.6
26.8
24.3
23.9
35.5
36.8
99.9
73.3
27.2
(mpge)
Average #
Cylinders
6
4.5
4.7
5.5
4.2
4.2
-
-
4.7
Table 4.1 shows the current adoption rates of electrification and engine improvement
technologies for the fourteen largest manufacturers. The technologies in Table 4.1 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 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.
50
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Figure 4.3. Manufacturer Use of Advanced Technologies for Model Year 202415
Tesla -
Honda -
Hyundai -
Kia -
T oyota -
Nissan -
BMW -
Subaru -
Mazda -
VW-
Mercedes -
Ford-
GM-
Stellantis -
All Manufacturers -
34%
28%
16%
33%
21%
85%
20%
24%
92%
81%
80%
64%
39%
45%
74%
29%
34%
0%
79%
56%
98%
100%
92%
89%
58%
91%
39%
56%
19%
40%
29%
92%
2%
29%
0%
0%
28%
0%
23%
71%
23%
30%
41%
68%
96%
46%
3%
7%
15%
49%
11%
13%
8%
8%
2%
29%
23%
56%
54%
52%
28%
84%
18%
90%
89%
87%
67%
94%
56%
62%
47%
55%
33%
58%
46%
88%
10%
75%
4%
82%
88%
65%
58%
0%
34%
12%
13%
82%
11%
5%
21%
12%
5%
32%
0%
12%
0%
10%
1%
2%
3%
4%
5%
2%
4%
1%
18%
3%
100%
4%
8%
8%
1%
2%
15%
2%
7%
11%
4%
5%
1%
7%
4%
1%
1
Turbo
—i—
GDI
~r
1 1 1
7+ Non-Hybrid MHEV
Gears StopStart
—i—
BEV
GDPI Cylinder CVT
Deactivation
HEV
PHEV
Diesel
15 In some cases, manufacturers have adopted a technology on a small number of vehicles that round to 0% of production. On this figure and
throughout the report, these instances are denoted as "0%" while technologies that have not been adopted in any amount are left blank.
-------
A. Vehicle Propulsion
As discussed above, all vehicles use at least one engine or electric motor to convert stored
energy into rotational energy to propel the vehicle forward. Over the 50 years that the EPA
has been collecting data, the technology used in engines, and now electric motors, has
continually evolved. The industry continues to develop new and innovative technologies to
improve vehicle efficiency, reduce emissions, increase vehicle performance, and increase
vehicle utility. 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 overtime.
Gasoline Engines
Since the EPA began tracking vehicle data in 1975, more than 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 vehicle 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 separately.
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 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
52
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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 60% of the market in model year 2024.
Figure 4.4. Gasoline Engine Production Share by Number of Cylinders
100%
75%
0
ro
_c
(J)
c
o
'-4-»
o
T3
O
50%
25%
0%
Cylinders
Less than 4
4 Cylinder
I 5 Cylinder
H 6 Cylinder
8 Cylinder
I More than 8
l 1 1 1 1 1 1 1 1 1 r
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
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 five liters), compared to an average of 159 cubic inches (about 2.6 liters) in
model year 2024. Gasoline engine displacement per cylinder has been relatively stable over
the time of this report (around 34 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
53
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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 more than
doubled between model year 1975 and model year 2024. 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 2024, relative
to the total displacement, is about 7% 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 performance and
efficiency improvements to internal combustion engines.
54
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Figure 4.5. Percent Change for Specific Gasoline Non-Hybrid Engine Metrics
200%
150%
LO
100%
CD
O
C
CD
g> 50%
c
CO
.C
o
0%
-50%
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Fuel Delivery Systems and Valvetrains
All gasoline engines require a fuel delivery system that controls the flow of fuel delivered
into the engine. The process for controlling fuel flow has changed significantly over time,
allowing for much more control over the combustion process and thus more efficient
engines. Figure 4.6 shows many different engine designs as they have entered, and in
many cases exited, the automotive market. Some fleetwide changes occurred gradually,
but in some cases (for example trucks in the late 1980s), engine technology experienced
widespread change in only a few years. Evolving technology offers opportunities to
improve fuel economy, power, and other vehicle parameters.
In the 1970s and early 1980s, nearly all gasoline engines used carburetors to meter fuel
delivered to the engine. Carburetors were replaced over time with fuel injection systems;
first throttle body injection (TBI) systems, then port fuel injection (PFI) systems, and more
recently gasoline direct injection (GDI) and combined gasoline direct and port injection
engines (GDPI), as shown in Figure 4.6. TBI and PFI systems use fuel injectors to
55
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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 almost 80% of the model year 2024 fleet had either GDI or GDPI. In
model year 2024, GDI engines were installed in 56% of new 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,
almost 90% of the fleet has converted to gasoline multi-valve engines. While some 3- and 5-
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.
56
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Figure 4.6. Production Share by Engine Technology
100%
75%
50%
25%
0%
"D 100%
~u
o
L.
75%
50%
25%
0%
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
Truck
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
57
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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 WT 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.
Figure 4.7. Engine Metrics for Different Gasoline Technology Packages
1.6
CL
X
1.2
CL
O
CL
w
0.4
CL
X
CL
X
o
0.06
0.05
0.04
0.03
0.02
Variable Timing,
Multi-Valve Engines
GDI Engines
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
GDI Engines
Variable Timing,
Multi-Valve Engines
Fixed Timing,
Single-Valve Engines
Carbureted Engines
58
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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 prevent premature combustion (engine knock), and
reduces turbo lag (the amount of time it takes for a turbocharger to engage).
Gasoline turbocharged engines (including HEVs and PHEVs) have grown steadily in the
marketplace, accounting for more than 44% of all vehicle production in model year 2024, 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 2024 are 4-cylinder engines. Model year 2025 is
projected to be a similar distribution, as shown in Figure 4.9.
59
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Figure 4.8. Gasoline Turbo Engine Production Share by Vehicle Type
40% -
30% -
CO
c
o
20% -
"O
O
CL
10%-
0%-
Vehicle Type
Sedan/Wagon
¦ Car SUV
Truck SUV
Minivan/Van
| Pickup
¦¦¦¦
nil
2003
2008
2013
Model Year
2018
2023
Figure 4.9. Gasoline Turbo Engine Production Share by Number of Cylinders
"O
o
40% -
30% -
20% -
10%-
0%-
Cylinders
3 Cylinder
4 Cylinder
I 6 Cylinder
8 Cylinder
I Other
ll
¦¦miiiiiillll
2003
2008
2013
Model Year
2018
2023
60
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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 electricity to 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 has fallen slightly since to 13% of all new model year 2024
vehicles. Projected model year 2025 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
restarted when the driver releases the brake pedal. By turning the engine off, a vehicle can
eliminate the fuel use 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 58% of all new gasoline non-hybrid vehicles in
model year 2024. Non-hybrid stop/start systems have been used in a wide range of
applications, including all vehicle types, as shown in Figure 4.10 and Figure 4.11.
61
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Figure 4.10. Gasoline Non-Hybrid Stop/Start Production Share by Vehicle Type
60%
50%
40%
-------
Hybrids
Gasoline hybrid vehicles feature a battery pack that is larger and higher-voltage 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 an electric 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.
The hybrid category includes "mild" hybrids (MHEVs), which employ a low voltage electrical
system that can provide launch assist and engine assist 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 DC or less electrical system are classified as mild hybrids,
while high 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 4% of all vehicles in model year 2010 before slowly declining to less than 2% 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 15% of all new
vehicles in model year 2024. Hybrid growth is projected to continue growing in model year
2025, to 19% 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 less than 25% of all hybrid production in model year 2024. Hybrid vehicles
typically use a 4-cylinder engine, although an increasing number of 6-cylinder engines are
being used in hybrid systems, as shown in Figure 4.13.
63
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Figure 4.12. Gasoline Hybrid Engine Production Share by Vehicle Type
20%
15%
0)
(0
-C
CO
g 10%
o
=5
"O
o
5%
0%
Vehicle Type
Sedan/Wagon
Car SUV
Truck SUV
Minivan/Van
| Pickup
- ..Illll
2000
2005
2010
2015
2020 2025
Model Year
Figure 4.13. Gasoline Hybrid Engine Production Share by Number of Cylinders
20%
15%
0)
(0
-C
(/)
c
o
"O
o
10%
5%
0%
Cylinders
4 Cylinder
| 6 Cylinder
8 Cylinder
¦ Other
ll
2000
2005
2010 2015
Model Year
2020
2025
64
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While strong hybrids have increased 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 35% of hybrid production
in model year 2024, as shown in Figure 4.14.
Figure 4.14. Gasoline Hybrid Engine Production Share Hybrid Type
2000
2005
2010 2015
Model Year
2020
2025
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
65
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of gasoline as a fuel source complicates the comparison of BEVs (and PHEVs) to ICE
vehicles, requiring different metrics16 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
geographical location, time of day, and weather.
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-powered 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. 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 in recent years. Prior to model year 2011,
BEVs were available, but generally only in small numbers for lease in California.17 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 2024
combined BEV/PHEV production accounted for almost 10% of all new vehicles. Combined
BEV and PHEV production is projected to reach a new high of 12% of all production in
model year 2025. In recent model years, there have been only two hydrogen FCEV models
produced, and they have only been available in small numbers in the states of California
and Hawaii. A third vehicle that can operate on hydrogen is included in the model year
2025 data, although that vehicle can also operate as a PHEV using electricity from an
external source. This vehicle is classified as a FCEV for this report since it is expected to
16 See Appendix E for a detailed discussion of BEV and PHEV metrics.
17 At least over the timeframe covered by this report. BEVs were initially produced more than 100 years ago.
66
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operate primarily on hydrogen and be released in limited markets. While there are limited
FCEV vehicles available today, there continues to be interest in FCEVs as a future
technology. The trend in production shares for BEVs, PHEVs, and FCEVs is shown in Figure
4.15.
Figure 4.15. Production Share of BEVs, PHEVs, and FCEVs18
12.5%
10.0%
-------
The inclusion of model year 2024 BEV and PHEV production increased new vehicle average
fuel economy by 1.7 mpg, as shown in Figure 4.16. Without BEV and PHEV production, the
fuel economy of the remaining new vehicles was relatively flat.
Figure 4.16. Impact of BEVs and PHEVs
28
26
? 24
22
All New Vehicles: 27.2
I
O
• •
• • • #
• • °
• • #
Without BEVs and PHEVs: 25.6
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.
68
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Figure 4.17. Battery Electric Vehicle Production Share by Vehicle Type
CD
03
-C
(/)
c
o
'¦4—'
o
"O
o
12%
9%
6%
3%
0%
Vehicle Type
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
CD
03
-C
(/)
c
o
'¦4—'
o
~o
o
12%
9%
6%
3%
0%
Vehicle Type
Sedan/Wagon
¦ Car SUV
Truck SUV
Minivan/Van
....¦¦¦II
2010
2015
2020
2025
Model Year
69
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Figure 4.19 shows the range and fuel economy trends for BEVs and PHEVs.19 The average
range of new BEVs has climbed substantially since their introduction. In model year 2024,
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 improved between model year 2011 and 2020 but has
been falling since, 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 2024 than in model year 2011. This may be attributable to
19 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.
70
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the growth of truck SUV PHEVs, as shown in Figure 4.18. For more information about BEV
and PHEV metrics, see Appendix E.
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
70
60
50
40
30
20
•
•
•
•
•
•
•
•
•
• •
. . •
: i i
i
\
• • I
i »
1 •
•
1 •
•
i
•
•
•
Vehicle Type
• Sedan/Wagon
• Car SUV
• Truck SUV
• Minivan/Van
• Pickup
3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000
Inertia Weight (lbs)
71
-------
Diesel Engines
Vehicles with diesel engines have been available in the U.S. at least as long as the EPA has
been collecting data. However, sales of diesel vehicles have rarely broken more than 1 % of
the overall light-duty market. Diesel vehicle sales peaked at 6% of the market in model year
1981 but have been at or below 1 % of production per year since 1985. In MY 2024, diesel
vehicles remained 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.
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 entirely comprised of 6-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 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.
72
-------
Figure 4.21. Diesel Engine Production Share by Vehicle Type
6%
CD
i_
03
-C
V)
c
o
o
"O
o
4%
Q_ 2%
0%
¦¦¦¦liaL i¦
Vehicle Type
SedanAAfegon
¦ Car SUV
Truck SUV
Minivan/Van
I Pickup
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 Cylinde
16 Cylinde
8 Cylinde
1 Other
?r
?r
?r
..1
ll..
III
t 1 1 1 r
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
73
-------
Figure 4.23. Percent Change for Specific Diesel Engine Metrics
250%
200%
LO
£ 150%
CD
O
& 100%
a>
O)
" 50%
O
0%
-50%
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
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.
74
-------
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 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 4.1. 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 strong
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 8-speed transmission will have more flexibility in determining
engine operation than a vehicle with a 5-speed transmission. This can lead to reduced fuel
consumption 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 1980.20 For this analysis, transmissions are separated into
20 The EPA has incomplete transmission data prior to model year 1980.
75
-------
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 the 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, 3-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 4-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 4-speed transmission. After model year 1999, the
production share of 4-speed transmissions slowly decreased as 5- and 6-speed
transmissions were introduced into the market. 6-speed transmissions peaked in model
year 2013 at 60% of new vehicle production, but then fell quickly, down to 8% by model
year 2024. 8-speed transmissions became the most popular transmission in model year
2019. In model year 2024, vehicles with 8-speed transmissions accounted for 33% of all
new vehicles, while vehicles with non-hybrid CVTs or vehicles with transmissions of nine or
more speeds each accounted for more than 20% of new vehicle production.
76
-------
Figure 4.24. Transmission Production Share
CD
CD
-C
CD
c
o
'¦4—'
o
"O
o
100%
75%
50%
25%
0%
100%
75%
50%
25%
0%
OT
~r
L3
AAy
A3
M3
L3
A3 A4
M6.
L5
L6
L8
W
L10
•L9
CVT(H)
LA
CVT(N-H) /\ .A8
i~A7
A6
M6-.
L7^
L5
L6
L4
L8
CVT(H).
CVT(N-H)
•A6
•SS
1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Transmission
Lockup?
Number of Gears
Key
Single Speed
-
1
SS
Automatic
No
2
A2*
Semi-Automatic
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
L8
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.
-------
Transmission trends also vary by vehicle engine technology, as shown in Figure 4.25. For
model year 2024, diesel engines were most often paired with a ten-speed lockup
transmission, with some 8-speed transmissions. Gasoline engines were paired with a wide
variety of transmissions, including CVTs, lockup transmissions from 10 to five speeds, a
small number of manual transmissions, and a small number of non-lockup transmissions
(likely DCTs). Mild hybrids are most often paired with an 8- or 9-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 Powertrain Technology, Model Year 2024
Diesel Gasoline MHEV HEV PHEV BEV
ICE
Fuel Type
78
-------
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
gradually declined and have been below 1 % of all production since model year 2021.
Today, manual transmissions are available only in a limited number of vehicles.
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, PHEVs, and vehicles with CVTs). 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
79
-------
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 2024. 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 2024. Four-wheel drive systems have steadily increased from 3% of new
vehicle production in model year 1975 to 63% of production in model year 2024. Four-
wheel drive systems have increased for both cars and trucks, but the high market
penetration rate of 86% 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.
80
-------
Figure 4.27. Front-, Rear-, and Four-Wheel Drive Production Share
100%
75%
<1)
&_
05
-C
CO
o 50%
o
~C5
o
CL
25% -
0%
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
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025
Model Year
81
-------
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 market 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 the EPA does not
begin tracking technology production share data until after the technologies had achieved
some limited market share. For example, the 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-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.
82
-------
Figure 4.28. Industry-Wide Car Technology Penetration after First Significant
Use
100%-
80% -
(D
ro
.£=
60% -
£=
O
-4—"
o
=3
o 40% -
CL
20% -
0% -
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.21 For each technology, Figure 4.29 shows
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.
0 10 20 30 40 50
Years after First Significant Use
21 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.
83
-------
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 predict the 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.
84
-------
Figure 4.29. Manufacturer Specific Technology Adoption over Time for Key
Technologies
<1)
3
O
a
3
C
05
Toyota ¦
GM ¦
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
Toyota ¦
GM ¦
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
Toyota ¦
GM •
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
Fuel Injection
1975 1980
1990
2000
2010
2020 2025
T
T
1975 1980
1990
2000
2010
2020 2025
Lockup
¦¦¦¦I
¦HI
¦
1
Multi-Valve
1975 1980
1990
2000
2010
2020 2025
Toyota -
GM -
Ford -
Honda -
Stellantis -
Hyundai-
Nissan -
Manufacturers-
1
1
Variable Valve
Timing
1975 1980
1990
2000
2010
2020 2025
Toyota ¦
GM •
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
Toyota ¦
GM •
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
Toyota ¦
GM-
Ford ¦
Honda¦
Stellantis -
Hyundai-
Nissan ¦
All Manufacturers-
T"
T"
1975 1980
1990
2000
2010
2020 2025
Advanced
Transmissions
Gasoline Direct
Injection
1975 1980
1990
2000
2010
2020 2025
Turbocharged
1975 1980 1990 2000 2010
Model Year
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%
85
-------
Table 4.2. Production Share by
Powertrain
Gasoline Gasoline Mild Strong Plug-in Battery Fuel Cell
ICE without ICE with Hybrid Hybrid Hybrid Electric Electric
Model Year
Diesel ICE
Stop/Start
Stop/Start
(MHEV)
(HE V)
(PHEV)
(BEV)
(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%
0.6%
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
0.7%
17.2%
57.6%
5.3%
9.5%
2.5%
7.2%
0.0%
-
2025 (prelim)
0.7%
12.6%
55.4%
5.1%
14.0%
2.4%
9.8%
0.0%
-
To explore this data in more depth, please see the report website at https://www.epa.gov/automotive-trends.
86
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Table 4.3. Production Share by Fuel Delivery Method
Gasoline Engines - Fuel Delivery Method
Model Year
Carbureted
TBI
Port
GDI
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%
2013
-
-
67.7%
30.5%
2014
-
-
60.9%
37.4%
2015
-
-
56.0%
41.9%
2016
-
-
48.7%
48.0%
2017
-
-
44.2%
49.7%
2018
-
-
37.7%
50.2%
2019
-
-
31.6%
52.9%
2020
-
-
26.6%
57.1%
2021
-
-
23.6%
53.4%
2022
-
-
21.0%
52.3%
2023
-
-
16.0%
50.5%
2024
12.5%
56.2%
2025 (prelim)
-
-
8.7%
52.0%
GDPI
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%
0.1%
0.9%
0.1%
0.0%
0.6%
0.9%
0.3%
-
0.4%
1.0%
0.3%
0.0%
0.7%
0.9%
0.5%
0.0%
2.3%
0.5%
0.5%
0.0%
5.2%
0.3%
0.6%
0.0%
10.3%
0.4%
1.4%
0.0%
14.2%
0.1%
1.2%
0.0%
14.0%
0.5%
1.8%
0.0%
18.7%
1.0%
3.2%
0.0%
20.6%
0.8%
5.2%
0.0%
22.9%
0.8%
9.8%
0.0%
23.3%
0.7%
7.2%
0.0%
28.9%
0.7%
9.8%
0.0%
87
-------
Table 4.4. Production Share by Gasoline22 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
251
86.9%
94.4%
16.6%
31.8%
44.0%
2022
4.9
171
251
86.7%
92.5%
15.9%
35.8%
48.9%
2023
4.9
170
255
83.0%
87.9%
15.1%
37.3%
49.2%
2024
4.7
159
247
87.1%
91.8%
13.3%
44.4%
57.6%
2025 (prelim)
4.6
156
248
86.0%
89.4%
11.7%
44.8%
55.4%
22 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.
88
-------
Table 4.5. Production Share by Transmission Technologies
Automatic
Automatic
CVT
4 Gears
Average
with
without
CVT
(Non-
or
5
6
7
8
9+
No. of
Model Year
Manual
Lockup
Lockup
(Hybrid)
Hybrid)
Other
Fewer
Gears
Gears
Gears
Gears
Gears
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
0.9%
59.0%
11.5%
7.8%
20.8%
-
7.2%
0.7%
7.9%
1.8%
33.2%
20.5%
7.0
2025 (prelim)
0.6%
54.4%
14.9%
11.0%
19.2%
^1
9.8%
0.0%
7.3%
1.6%
30.4%
20.6%
7.0
89
-------
Table 4.6. Production Share by Drive Technology
Car
Truck
Front
Rear
Four
Front
Rear
Wheel
Wheel
Wheel
Wheel
Wheel
Model Year
Drive
Drive
Drive
Drive
Drive
1975
6.5%
93.5%
-
-
82.8%
1980
29.7%
69.4%
0.9%
1.4%
73.6%
1985
61.1%
36.8%
2.1%
7.3%
61.4%
1990
84.0%
15.0%
1.0%
15.8%
52.4%
1995
80.1%
18.8%
1.1%
18.4%
39.3%
2000
80.4%
17.7%
2.0%
20.0%
33.8%
2005
79.2%
14.2%
6.6%
20.1%
27.7%
2010
82.5%
11.2%
6.3%
20.9%
18.0%
2011
80.1%
11.3%
8.6%
17.7%
17.3%
2012
83.8%
8.8%
7.5%
20.9%
14.8%
2013
83.0%
9.3%
7.7%
18.1%
14.5%
2014
81.3%
10.6%
8.2%
17.5%
14.2%
2015
80.4%
9.7%
9.9%
16.0%
12.6%
2016
79.8%
9.1%
11.0%
15.9%
12.2%
2017
79.7%
8.3%
12.0%
16.1%
11.1%
2018
76.5%
9.4%
14.1%
13.4%
10.9%
2019
75.5%
10.1%
14.4%
14.4%
10.2%
2020
76.5%
8.8%
14.7%
12.5%
10.0%
2021
70.7%
11.2%
18.0%
8.5%
9.2%
2022
65.9%
11.2%
22.9%
10.0%
8.9%
2023
60.3%
14.9%
24.8%
9.5%
7.2%
2024
68.4%
10.8%
20.8%
8.8%
5.7%
2025 (prelim)
65.1%
10.2%
24.7%
8.8%
6.8%
All
Four
Front
Rear
Four
Wheel
Wheel
Wheel
Wheel
Drive
Drive
Drive
Drive
17.2%
5.3%
91.4%
3.3%
25.0%
25.0%
70.1%
4.9%
31.3%
47.8%
42.9%
9.3%
31.8%
63.8%
26.1%
10.1%
42.3%
57.6%
26.3%
16.2%
46.3%
55.5%
24.3%
20.2%
52.2%
53.0%
20.2%
26.8%
61.0%
59.6%
13.7%
26.7%
65.0%
53.8%
13.8%
32.4%
64.3%
61.4%
10.9%
27.7%
67.5%
59.7%
11.1%
29.1%
68.3%
55.3%
12.1%
32.6%
71.4%
52.9%
10.9%
36.1%
72.0%
51.2%
10.5%
38.3%
72.8%
49.6%
9.6%
40.8%
75.6%
43.7%
10.2%
46.1%
75.4%
41.6%
10.1%
48.3%
77.5%
40.6%
9.4%
49.9%
82.3%
31.6%
10.0%
58.5%
81.0%
30.6%
9.8%
59.6%
83.4%
28.5%
10.1%
61.4%
85.5%
29.2%
7.5%
63.3%
84.4%
28.3%
7.9%%
63.7%
90
-------
Appendices: Methods and
Additional Data
A. Sources of Input Data
Nearly all the data for this report are based on automakers' direct submissions to the EPA.
The 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 the 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 (DOT), 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, the EPA has been responsible for establishing test procedures and
calculation methods and for collecting data used to determine vehicle fuel economy levels.
The EPA calculates the CAFE value for each manufacturer and provides it to the NHTSA. The
NHTSA publishes the final CAFE values in its annual "Summary of Fuel Economy
Performance" reports at https://one.nhtsa.gov/cafe pic/home.
The data that the 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 the
EPA. This database contains a broad amount of data associated with 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 the EPA. For example, the EPA relied on
published data from external sources for certain parameters of pre-model year 2011
vehicles: (1) engines with variable valve timing (VVT), (2) engines with cylinder deactivation,
and (3) vehicle footprint, as automakers did not submit this data until model year 2011. The
EPA projects footprint data for the preliminary model year 2025 fleet based on footprint
values for existing models from previous years and footprint values for new vehicle designs
A-1
-------
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. The EPA plans to continue to add
content and tools on the web to allow transparent access to public data. To explore the
data using the 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 the 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 the EPA and
the NHTSA regulatory programs.
Preliminary data are collected prior to the beginning of each model year and are not used
for manufacturer 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 the
EPA.
Final data are submitted a few months after the end of each model year and include
detailed final production volumes. The EPA and the NHTSA use this final data to determine
compliance with the CAFE standards. These end-of-the-year submissions include detailed
final production volumes. All data in this report for model years 1975 through 2024 are
considered final.
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
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. 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
A-2
-------
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
28.0
27.2
-0.8
2025 (prelim)
28.1
A-3
-------
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
assumes 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 examples above, a harmonic average will typically yield a result that is slightly
lower than the arithmetic average.
B-1
-------
The following equation illustrates the use of harmonic averaging to obtain the correct
mathematical result for the fuel economy example above:
2
Average mpg = -j ^7 = 24 mP§
\30 + 20 j
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
10
Average mpg = —^^ j- = 24.4 mpg
ho + 25 + 20)
(Note that, 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
emissions values (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.
In summary, fuel economy values must be harmonically averaged to maintain mathematical
integrity, while fuel consumption values (in gallons per mile) and emissions values (in grams
per mile) can be arithmetically averaged.
B-2
-------
C. Fuel Economy Metrics
The fuel economy data in this report are estimated real-world data. The following
sections discuss the differences between CAFE compliance data 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,
the EPA tested vehicles using two dynamometer-based test cycles, one based on city
driving and one based on highway driving. CAFE was—and continues to be—required by
law to use these "2-cycle tests".
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.
The 2-cycle testing methodology has remained largely unchanged since the early 1970s.23
Because of this, the 2-cycle fuel economy values can serve as a useful comparison of long-
term trends. Previous versions of this report included 2-cycle fuel economy data, referred
to as "unadjusted" or "laboratory" values. These 2-cycle fuel economy values are still
available on the report website for reference.
Estimated Real-World Fuel Economy Data
Estimated real-world (previously called "adjusted") data is the EPA's best estimate of real-
world fuel economy, as reported in Sections 1 -4 of this report. The real-world values are
the best data for researchers to evaluate new vehicle fuel economy performance. Unlike
compliance data, the method for calculating real-world data has evolved over time, along
23 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. The 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.
C-1
-------
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
and higher acceleration) that an average driver will encounter. City and highway results are
weighted 43% / 57%, consistent with fleetwide driver activity data.
Example Comparison of Fuel Economy Metrics
The multiple ways of measuring fuel economy 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 Prius results in a city fuel economy of 83 mpg, a highway fuel economy of
78 mpg, and a combined 2-cycle value of 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
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.
C-2
-------
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
C-3
-------
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 through the historical database. The current version of this report supersedes all
previous reports.
Changes in Estimated Real-world Fuel Economy
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.
Model year 1975-1985: Universal Multipliers
The first change to the label methodology occurred when the 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, the 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 values are
based on a 55% city / 45% highway weighting factor, consistent with the CAFE.
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Model year 1986-2010: The 2006 5-cycle methodology and 43% City / 57%
Highway Weighting
In 2006, the EPA established a major change to the fuel economy label calculations by
introducing the 5-cycle methodology.24 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 several
factors that are not reflected in EPA laboratory test data (e.g., changing fuel composition,
wind, road conditions) using 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, the 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.25 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.
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
24 See 71 Federal Register 77872, December 27, 2006.
25 See 71 Federal Register 77883-77886, December 27, 2006.
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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 =
(°-
003259 +
1.1805 >
2CYCLE CITYJ
1
Label HWY =
(0.001376 +
1.3466
2 CYCLE HWY;
Over the same timeframe, the EPA phased in a change in the city and highway weightings
used to determine a single combined fuel economy. The 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.26 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 EPA and NHTSA 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.
Model year 2011 -present: Implementing the 2017 derived 5-cycle updates
In 2015, the 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.27 This
26 See 71 Federal Register 77904, December 27, 2006.
27 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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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 +
Label HWY =
1.1601
2CYCLE CITY;
1
/ 1 2945
(0.003191 +¦
2 CYCLE HWYV
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.
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Figure D.1. Estimated Real-World versus 2-Cycle Fuel Economy since Model
Year 1975
Phase I
1975-1985
Universal
adjustment factors
55/45% weighting
Phase II
1986-2006
Phase III
2007-2010
Phase IV
2011-present
2006 5-cycle is phase-in
43/57% weighting phase-in
5-cycle
43/57%
weighting
Updated 5-cycle
43/57% weighting
f Ratio of^
Real-Wo rid
Estimated
to 2-cycle:
85.2% J
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 the 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 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 electric vehicles, and compressed natural gas vehicles. 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
the EPA and the NHTSA for compliance with 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 the 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 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 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 previous GHG Regulations
The data used to discuss real-world trends this report are based on production volumes
reported under CAFE prior to model year 2017. Beginning in model year 2018, the
production volumes are based on EPA's previous GHG regulations. The production volume
levels automakers provided 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. The differences in production volumes are very
small and do not impact the long-term trends or analysis. Future production volumes will
be determined based on available data.
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E. Plug-In Hybrid Fleet Average Data
Calculating fuel economy 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.
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 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 the 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 fuel economy standards. The regulatory definitions of passenger vehicles (cars) and
light trucks (trucks) are in NHTSA's CAFE regulations (49 CFR § 523.5). The 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
(49 USC §32901).
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 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-highway capabilities. Any light-duty vehicles that do not meet the above functionality or
off-highway 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
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G. Naming Conventions for Electrified
Vehicles
This report identifies several electrification technologies currently being deployed on new
vehicles. This report uses the conventions shown in Figure G.1 to identify specific vehicle
technology types and groupings.
Figure G.1. Electrification Groupings of Vehicles
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).
• 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.
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• 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 DC 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 a high-voltage battery that can temporarily power the vehicle without engaging
the engine; strong hybrids typically 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 DC and an internal combustion engine are
classified as "strong" hybrids.
• Plug-in Hybrid Electric Vehicle (PHEV): These vehicles have a battery that can be
charged from an external electrical source as well as by an internal combustion
engine, and the vehicle can 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, Hannah Frame,
Sarah Harrison, Joshua Kimball, Aaron Sobel, 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 the EPA Headquarters in Washington,
District of Columbia. OTAQ colleagues including Karen Danzeisen, Robert Peavyhouse, 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 the EPA Office of Public Affairs for greatly improving the design and layout of the
report. 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. Roberts French originally developed the former compliance portion of this
report and provided valuable input throughout the report. This report has benefitted
immensely from the wealth of insight, creativity, and dedication from each of these
outstanding emeriti authors.
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