Light-Duty Automotive Technology, 


Carbon Dioxide Emissions, and 


Fuel Economy Trends:
 

1975 Through 2014 


Report

EPA-420-R -14-023a October 2014 
NOTICE: 

This technical report does not necessarily represent final EPA decisions or positions. It is 

intended to present technical analysis of issues using data that are currently available. The 

purpose in the release of such reports is to facilitate the exchange of technical information 

and to inform the public of technical developments. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE OF CONTENTS 

I. Introduction .................................................................................................................................................................. 1
 

2. Fleetwide Trends Overview ........................................................................................................................................... 3
 

A. Overview of Final MY 2013 Data ...................................................................................................................................... 3
 

B. Overview of Preliminary MY 2014 Data ........................................................................................................................... 3
 

C. Overview of Long-Term Trends ........................................................................................................................................ 6
 

3. Vehicle Class, Type, and Attributes.............................................................................................................................. 14
 

A. Vehicle Class ................................................................................................................................................................... 14
 

B. Vehicle Type.................................................................................................................................................................... 16
 

C. Vehicle Footprint, Weight, and Horsepower .................................................................................................................. 22
 

D. Vehicle Acceleration ....................................................................................................................................................... 32
 

4. Manufacturers and Makes .......................................................................................................................................... 37
 

A. Manufacturer and Make Definitions .............................................................................................................................. 37
 

B. Manufacturer and Make Fuel Economy and CO2 Emissions........................................................................................... 39
 

C. Manufacturer Technology and Attribute Trends............................................................................................................ 47
 

5. Powertrain Technologies ............................................................................................................................................. 52
 

A. Trends in Engine Power and Size (Cylinders and Displacement) .................................................................................... 52
 

B. Trends in Fuel Delivery Methods and Valvetrains .......................................................................................................... 56
 

C. New Powertrain Strategies: Turbo Downsizing, Hybrids, and Diesels ............................................................................ 59
 

D. Trends in Transmission Types......................................................................................................................................... 73
 

E. Trends in Drive Types...................................................................................................................................................... 77
 

6. Techology Adoption Rates ........................................................................................................................................... 83
 

A. Industry-Wide Technology Adoption Since 1975 ........................................................................................................... 84
 

B. Technology Adoption by Manufacturers ........................................................................................................................ 85
 

C. Technology Adoption in the Last Five Years ................................................................................................................... 91
 

7. Alternative Fuel Vehicles ............................................................................................................................................. 92
 

A. Methodology .................................................................................................................................................................. 92
 

B. Historical Trends ............................................................................................................................................................. 94
 

C. MY 2014 Vehicles............................................................................................................................................................ 96
 

D. Overall Impact of Alternative Fuel Vehicles ................................................................................................................. 106
 

8. High Fuel Economy/Low CO2 and Advanced Technology Choices .............................................................................. 108
 

A. Methodology ................................................................................................................................................................ 108
 

B. High Fuel Economy Vehicle Offerings ........................................................................................................................... 110
 

C. Advanced Technology Vehicle Offerings ...................................................................................................................... 111
 

9. Regulatory Context.................................................................................................................................................... 112
 

A. Personal Vehicle Fuel Economy and Greenhouse Gas Emissions Standards................................................................ 112
 

B. Current Vehicles That Meet Future EPA CO2 Emissions Compliance Targets............................................................... 113
 

C. Comparison of EPA and NHTSA Fuel Economy Data, 1975-2014 ................................................................................. 115
 

D. Comparison of MY 2013 Unadjusted, Laboratory and Estimated CAFE Data by Manufacturer .................................. 117
 

10. Additional Database and Report Details .................................................................................................................. 119
 

A. Sources of Input Data ................................................................................................................................................... 119
 

B. Harmonic Averaging of Fuel Economy Values .............................................................................................................. 120
 

C. Adjusted vs. Unadjusted, Laboratory Fuel Economy Values ........................................................................................ 121
 

D. Vehicle Tailpipe CO2 Emissions Data ............................................................................................................................ 129
 

E. Vehicle-Related GHG Emissions Sources Other Than Tailpipe CO2 Emissions .............................................................. 131
 

F. Other Database Methodology Issues ............................................................................................................................ 133
 

G. Comparison of Preliminary and Final Fleetwide Fuel Economy Values ....................................................................... 134
 

H. Definitions and Acronyms ............................................................................................................................................ 136
 

I. Links for More Information............................................................................................................................................ 138
 

J. Authors and Acknowledgements .................................................................................................................................. 139
 

References .................................................................................................................................................................... 140
 

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LIST OF FIGURES
 

Figure 2.1 Adjusted CO2 Emissions by Model Year...................................................................................................................... 6
 

Figure 2.2 Adjusted Fuel Economy by Model Year...................................................................................................................... 7
 

Figure 2.3 Adjusted Fuel Economy, Weight, and Horsepower by Model Year............................................................................ 8
 

Figure 2.4 Adjusted Fuel Economy Distribution by Model Year ................................................................................................ 10
 

Figure 3.1 Car and Truck Production Share by Model Year ...................................................................................................... 15
 

Figure 3.2 Vehicle Classes and Types Used in This Report ........................................................................................................ 16
 

Figure 3.3 Car Type Vehicle Production vs. Interior Volume for High Volume Manufacturers, MY 1978 and MY 2014........... 17
 

Figure 3.4 Vehicle Type Production Share by Model Year ........................................................................................................ 19
 

Figure 3.5 Adjusted CO2 Emissions, Adjusted Fuel Economy and Other Key Parameters by Vehicle Type ............................... 27
 

Figure 3.6 Car and Truck Production Share by Vehicle Inertia Weight Class ............................................................................ 28
 

Figure 3.7 Unadjusted, Laboratory Fuel Consumption vs. Footprint, Cars and Trucks, MY 2013 ............................................. 29
 

Figure 3.8 Unadjusted, Laboratory Fuel Consumption vs. Inertia Weight, Cars and Trucks, MY 1975 and MY 2013 .............. 30
 

Figure 3.9 Unadjusted, Laboratory Fuel Consumption vs. Car Interior Volume Cars, MY 1978 and MY 2013 ......................... 31
 

Figure 3.10 Calculated 0-to-60 Acceleration Performance....................................................................................................... 32
 

Figure 3.11 Acceleration Performance by Vehicle Type............................................................................................................ 33
 

Figure 3.12 Comparison of Two Methods for Calculated 0-to-60 Acceleration Performance .................................................. 35
 

Figure 4.1 Highest Technology Adoption Based on Projected MY 2014 Production................................................................. 47
 

Figure 4.2 Adjusted Fuel Economy and Percent Truck by Manufacturer for MY 1975 - 2014 .................................................. 51
 

Figure 5.1 Engine Power and Displacement ............................................................................................................................. 53
 

Figure 5.2 Percent Change for Specific Engine Metrics ............................................................................................................ 54
 

Figure 5.3 Production Share by Number of Engine Cylinders ................................................................................................... 55
 

Figure 5.4 Production Share by Engine Technology.................................................................................................................. 57
 

Figure 5.5 Engine Metrics for Different Engine Technology Packages ..................................................................................... 58
 

Figure 5.6 Market Share of Gasoline Turbo Vehicles ................................................................................................................ 60
 

Figure 5.7 Distribution of Gasoline Turbo Vehicles by Displacement and Horsepower, MY 2010 - 2014 ................................. 61
 

Figure 5.8 Hybrid Production MY 2000 - 2014 (With 3-Year Moving Average) ........................................................................ 62
 

Figure 5.9 Hybrid Adjusted Fuel Economy Distribution by Year, Cars Only .............................................................................. 63
 

Figure 5.10 Hybrid and Non-Hybrid Fuel Economy for Midsize Cars, MY 2000 - 2014 ............................................................. 64
 

Figure 5.11 Highway/City Fuel Economy Ratio for Hybrids and Non hybrids ........................................................................... 65
 

Figure 5.12 Percent Improvement in Adjusted Fuel Consumption for Hybrid Vehicles, MY 2013 ............................................ 66
 

Figure 5.13 Percent Improvement in Adjusted Fuel Consumption for Diesel Vehicles, MY 2013 ............................................. 68
 

Figure 5.14 Percent Improvement in CO2 Emissions for Diesel Vehicles, MY 2013 ................................................................... 69
 

Figure 5.15 Transmission Production Share ............................................................................................................................. 74
 

Figure 5.16 Average Number of Transmission Gears for New Vehicles (excluding CVTs) ........................................................ 75
 

Figure 5.17 Comparison of Manual and Automatic Transmission Adjusted Fuel Economy ..................................................... 76
 

Figure 5.18 Front, Rear, and Four Wheel Drive Usage - Production Share by Vehicle Type ..................................................... 78
 

Figure 5.19 Differences in Adjusted Fuel Consumption Trends for FWD, RWD, and 4WD/AWD Vehicles, MY 2013 ............... 79
 

Figure 6.1 Industry-Wide Car Technology Penetration after First Significant Use................................................................... 85
 

Figure 6.2 Manufacturer Specific Technology Adoption over Time for Key Technologies ....................................................... 87
 

Figure 6.3 Maximum Three- and Five-Year Adoption for Key Technologies ............................................................................. 89
 

Figure 6.4 VVT Adoption Details by Manufacturer ................................................................................................................... 90
 

Figure 6.5 Five Year Change in Light Duty Vehicle Technology Penetration Share................................................................... 91
 

Figure 7.1 Historical Production of EVs, PHEVs, and Dedicated CNG Vehicles, MY 1995 - 2013 .............................................. 95
 

Figure 8.1 Number of Models Meeting Fuel Economy Thresholds in MY 2009 and MY 2014 ................................................ 110
 

Figure 8.2 Advanced Technology and Alternative Fueled Vehicle Models in MY 2009 and MY 2014 .................................... 111
 

Figure 9.1 MY 2014 Vehicle Production That Meets Future CO2 Emission Targets with Current Powertrains ....................... 114
 

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LIST OF TABLES 

Table 2.1 Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year.............................................. 5
 

Table 2.2 Comparison of MY 2013 with MY 2008 and MY 2004 .............................................................................................. 10
 

Table 2.3 Top Ten Highest Unadjusted, Laboratory Fuel Economy Gasoline/Diesel Vehicles Since 1975 ................................ 12
 

Table 2.4 Top Ten Highest Unadjusted, Laboratory Fuel Economy Gasoline/Diesel Truckss Since 1975 ................................. 13
 

Table 3.1 Vehicle Type Production Share by Model Year.......................................................................................................... 20
 

Table 3.2 Car-Truck Classification of SUVs with Inertia Weights of 4000 Pounds or Less ........................................................ 21
 

Table 3.3.1 Car Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year .................................. 24
 

Table 3.3.2 Truck Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year ............................... 26
 

Table 3.4 Comparison Between 0-to-60 Acceleration Time Calculation Methods by Model Year (seconds) ........................... 36
 

Table 4.1 Manufacturers and Makes for MY 2012 - 2014 ........................................................................................................ 38
 

Table 4.2 Adjusted Fuel Economy (MPG) by Manufacturer and Make for MY 2012 - 2014 ..................................................... 41
 

Table 4.3 Adjusted CO2 Emissions (g/mi) by Manufacturer and Make for MY 2012 - 2014 ..................................................... 43
 

Table 4.4 Unadjusted, Laboratory Fuel Economy (MPG) by Manufacturer and Make for MY 2012 - 2014 ............................. 45
 

Table 4.5 Unadjusted, Laboratory CO2 Emissions (g/mi) by Manufacturer and Make for MY 2012 - 2014 ............................. 46
 

Table 4.6 Footprint (square feet) by Manufacturer for MY 2012 - 2014 .................................................................................. 48
 

Table 4.7 Adjusted Fuel Economy and Production Share by Vehicle Classification and Type for MY 2013 .............................. 49
 

Table 4.8 Vehicle Footprint, Weight, and Horsepower by Manufacturer for MY 2013 ............................................................ 50
 

Table 5.1 Distribution of MY 2014 Turbocharged Engines (Excludes Diesel)............................................................................ 60
 

Table 5.2.1 Engine Technologies and Parameters, Both Cars and Trucks ................................................................................ 70
 

Table 5.2.2 Engine Technologies and Parameters, Cars Only ................................................................................................... 71
 

Table 5.2.3 Engine Technologies and Parameters, Trucks Only ............................................................................................... 72
 

Table 5.3.1 Transmission and Drive Technologies, Both Cars and Trucks ................................................................................ 80
 

Table 5.3.2 Transmission and Drive Technologies, Cars Only ................................................................................................... 81
 

Table 5.3.3 Transmission and Drive Technologies, Trucks Only................................................................................................ 82
 

Table 7.1 MY 2014 Alternative Fuel Vehicle Classification and Size ......................................................................................... 96
 

Table 7.2 MY 2014 Alternative Fuel Vehicle Powertrain and Range ........................................................................................ 98
 

Table 7.3 MY 2014 Alternative Fuel Vehicle Fuel Economy Label Metrics.............................................................................. 100
 

Table 7.4 MY 2014 Alternative Fuel Vehicle Label Tailpipe CO2 Emissions Metrics ................................................................ 102
 

Table 7.5 MY 2014 Alternative Fuel Vehicle Upstream CO2 Emission Metrics........................................................................ 105
 

Table 7.6 MY 2013 Alternative Fuel Vehicle Impact on Manufacturer Averages ................................................................... 107
 

Table 9.1 EPA Adjusted, EPA Unadjusted Laboratory, and CAFE Values by Model Year ........................................................ 116
 

Table 9.2 Comparison of MY 2013 EPA Unadjusted, Laboratory and Estimated CAFE (MPG) Values by Manufacturer........ 118
 

Table 10.1 Unadjusted, Laboratory and Adjusted Fuel Economy (MPG) for MY 1975 - MY 2014, Cars and Trucks............... 123
 

Table 10.2 Four Different Fuel Economy Metrics for the MY 2005 Honda Insight ................................................................. 128
 

........................................................................................................................................................................................... 130
 

Table 10.3 Factors for Converting Industry-Wide Fuel Economy Values from this Report to Carbon Dioxide Emissions Values
 

Table 10.4 Comparison of Preliminary and Final Fuel Economy Values, Both Cars and Trucks.............................................. 135
 

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Introduction 

This annual report (often referred to as the “Trends” report) is the authoritative reference 

on new light-duty (or personal) vehicle carbon dioxide (CO2) emissions, fuel economy, and 

powertrain technology trends in the United States. These vehicles include passenger cars, 

sport utility vehicles, minivans, and all but the largest pickup trucks and vans. This report 

uses the most comprehensive database of its kind, both because it is comprised of detailed 

new vehicle test data provided, under statute, to EPA by automobile manufacturers, and 

because the database has been rigorously maintained since 1975. Since major 

methodological changes are generally propagated backwards through the historical 

database in order to maintain the integrity of long-term trends, this report supersedes 

previous versions in the series and should not be compared to past reports. 

Except where noted, all data reflect the 99+% of new personal vehicles 

that are dedicated to or are expected to operate primarily on gasoline 

or diesel fuel (including flexible fuel and conventional hybrid vehicles, 

but excluding plug-in hybrid electric vehicles). Sections 7-9 provide 

relevant data from electric, plug-in hybrid electric, and compressed 

natural gas vehicles produced for the U.S. market. 

Trends generally uses the 

term “fleetwide” to 

represent gasoline and 

diesel fueled vehicles, which 

account for 99+% of all 

vehicles produced since 

1975. 

Trends uses harmonic 

averaging for fuel economy, 

which is essential to maintain 

mathematical integrity. 

The CO2 emissions and fuel economy data in this report are 

generated from EPA test procedures that have been refined over 

time. The CO2 emissions data in this report reflect the sum of the 

vehicle tailpipe emissions of CO2, carbon monoxide, and 

hydrocarbons, with the latter two converted to equivalent CO2 

levels on a mass basis. While carbon monoxide and hydrocarbon 

emissions add, on average, less than one percent to overall CO2 tailpipe emissions values, 

these compounds are included because they are converted to CO2 relatively quickly in the 

atmosphere, and to maintain consistency with greenhouse gas (GHG) emissions standards 

compliance. The tailpipe CO2 emissions data do not reflect other vehicle greenhouse gases 

(such as methane, nitrous oxide, or air conditioner refrigerants) or CO2 emissions 

associated with vehicle production and disposal, or fuel production and distribution, all of 

which are briefly discussed in Section 10. 

The data in this report are tabulated on a model year (MY), not calendar year, basis and 

reflect MY 1975-2014. Data through MY 2013 are final, while data for MY 2014 are 

preliminary and will be finalized in next year’s report. Vehicle population data represent 

production volumes delivered for sale in the U.S. market, rather than actual sales. 

Most of the data in this report reflect arithmetic production-weighted 

averages of individual CO2 emissions values and harmonic 

production-weighted averages of individual fuel economy values (see 

Section 10 for an explanation of why harmonic averaging is necessary 

for fuel economy). The data in Sections 7 and 8 reflect individual 

model counts independent of production volumes. 

Trends uses vehicle production 

data, not vehicle sales data, 

and aggregates production 

data for model years, not 

calendar years. 

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Unless noted, the CO2 emissions and fuel economy values in this report are expressed as 

adjusted values based, in recent years, on EPA’s 5-cycle test methodology (reflecting urban 

commuting, rural highway, high speed/acceleration, high temperature/air conditioning, 

and cold temperature operation). These adjusted values use a 43% city/57% highway 

weighting in order to be consistent with the national driving activity analysis underlying the 

development of the 5-cycle test methodology, and yield EPA’s best estimate of real world 

CO2 emissions and fuel consumption. See Section 10 for a detailed explanation of the 

methodology for how these adjusted values are calculated over the historical database. 

Type of CO2 and Fuel 

Economy Data Purpose 

City/Highway 

Weighting 

Adjusted 

Best estimate of real world 

performance 43%/57% 

Unadjusted, Laboratory 

Basis for automaker compliance 

with standards 55%/45% 

Test Basis 

5 cycle 

(see text) 

2 cycle 

(see text) 

This report occasionally provides unadjusted, laboratory CO2 emissions and fuel economy 

values based on EPA’s 2-cycle test methodology (reflecting urban commuting and rural 

highway operation only). These unadjusted values are weighted 55% city/45% highway 

when used as the basis for automaker compliance with GHG emissions and corporate 

average fuel economy (CAFE) standards. Adjusted CO2 emissions values are, on average, 

about 25% higher than unadjusted CO2 values, and adjusted fuel economy values are about 

20% lower than unadjusted fuel economy values. Because the methodology for 

determining unadjusted, laboratory values has remain largely unchanged while the 

methodology for adjusted values has evolved over time to better reflect real world driving, 

the former values provide a much better metric for comparing trends in vehicle design. 

This report does not provide formal compliance values, which are based on unadjusted, 

laboratory values as well as various credits, for either GHG emissions or CAFE standards. 

Information about automaker compliance with EPA’s GHG emissions standards, including 

EPA’s Manufacturer Performance Report for the 2012 Model Year, is available at 

epa.gov/otaq/regs/ld-hwy/greenhouse/ld-ghg.htm. NHTSA’s “Summary of Fuel Economy 

Performance,” summarizing automaker compliance with fuel economy standards, is 

available at nhtsa.dot.gov/fuel-economy. 

Changes to this year’s report: 

•	 Section 3 has an expanded discussion of 0 to 60 mph acceleration 

projections, with a new approach for calculating 0 to 60 values 

•	 Section 7 has a new sub section discussing the potential impact of 

including alternative fuel vehicles on automaker CO2 emissions 

and fuel economy values 

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Fleetwide Trends Overview 

This section provides an overview of important fleetwide data for MY 1975-2014, including a reference table for 

CO2 emissions, fuel economy, and several other key parameters. Fleetwide refers to the production-weighted 

analysis of the 99+% of new vehicles that are dedicated to or are expected to operate primarily on gasoline or 

diesel fuel. Unless otherwise noted, all CO2 emissions and fuel economy data are adjusted values that reflect real 

world performance, and are not comparable to unadjusted, laboratory values that are the basis for EPA GHG 

emissions and NHTSA CAFE standards compliance. Subsequent sections of the report analyze the Trends data in 

more detail. 

A. OVERVIEW OF FINAL MY 2013 DATA 

Table 2.1 shows that the fleetwide average real world CO2 emissions rate for new vehicles 

produced in MY 2013 is 369 grams per mile (g/mi), a 7 g/mi decrease from MY 2012. The 

MY 2013 fuel economy value is 24.1 miles per gallon (mpg), a 0.5 mpg increase from MY 

2012. These MY 2013 values, which represent an all-time record low for CO2 emissions and 

record high for fuel economy, are based on final data. Both CO2 emissions and fuel economy 

have improved in eight of the last nine years, the first time this has occurred since the database 

began in 1975. 

Truck production share of the overall personal vehicle market increased by 1 percentage point 

in MY 2013. Car-truck production share had been very volatile in recent years, and has had 

significant impacts on other parameters. Average personal vehicle weight increased by 38 

pounds (1.0%) in MY 2013. Power increased by 5 horsepower (2.3%), and is at its second 

highest level ever. Average vehicle footprint increased by 0.4 square foot (0.8%), remaining 

within a fairly narrow band over the last few years. 

Tables 3.3.1 and 3.3.2, shown later in this report, disaggregate the data in Table 2.1 for the 

individual car and truck fleets, respectively, for MY 1975-2014. 

B. OVERVIEW OF PRELIMINARY MY 2014 DATA 

Preliminary MY 2014 adjusted values are 367 g/mi CO2 emissions and 24.2 mpg fuel 

economy, which, if achieved, will represent record levels and a slight improvement over MY 

2013. The preliminary MY 2014 data suggest that truck production share will increase by 2%, 

vehicle weight will increase somewhat, footprint will remain unchanged, and power will reach 

an all-time high. 

We caution the reader about focusing on these preliminary MY 2014 values for several 

reasons. The production estimates for these values were provided to EPA by automakers in 

2013. As discussed in Section 10, over the last decade the final fuel economy value has been 

more favorable than the preliminary value in seven of those years. Two manufacturers, 

Hyundai and Kia, adopted unusually short MY 2014 production time frames for some of their 

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highest fuel economy vehicles. Estimating the possible impact, by excluding Hyundai and Kia 

data, yielded annual fuel economy increases for all other manufacturers of 0.4 mpg for both 

MY 2013 and preliminary MY 2014. Final values for MY 2014, based on actual production 

values, will be published in next year’s report. 

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Table 2.1 

Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year1, 2 

New Gasoline and Diesel Vehicles Alternative 

Fuel Vehicle 

Adj Adj Fuel Share of All 

Model Production CO2 Economy Weight Footprint Car Truck Vehicle 

Year (000) (g/mi) (MPG) (lb) HP (sq ft) Production Production Production 

1975 10,224 681 13.1 4060 137 - 80.7% 19.3% 0.0% 

1976 12,334 625 14.2 4079 135 - 78.9% 21.1% 0.0% 

1977 14,123 590 15.1 3982 136 - 80.1% 19.9% 0.0% 

1978 14,448 562 15.8 3715 129 - 77.5% 22.5% 0.0% 

1979 13,882 560 15.9 3655 124 - 77.9% 22.1% 0.0% 

1980 11,306 466 19.2 3228 104 - 83.5% 16.5% 0.0% 

1981 10,554 436 20.5 3202 102 - 82.8% 17.2% 0.0% 

1982 9,732 425 21.1 3202 103 - 80.5% 19.5% 0.0% 

1983 10,302 426 21.0 3257 107 - 78.0% 22.0% 0.0% 

1984 14,020 424 21.0 3262 109 - 76.5% 23.5% 0.0% 

1985 14,460 417 21.3 3271 114 - 75.2% 24.8% 0.0% 

1986 15,365 407 21.8 3238 114 - 72.1% 27.9% 0.0% 

1987 14,865 405 22.0 3221 118 - 72.8% 27.2% 0.0% 

1988 15,295 407 21.9 3283 123 - 70.9% 29.1% 0.0% 

1989 14,453 415 21.4 3351 129 - 70.1% 29.9% 0.0% 

1990 12,615 420 21.2 3426 135 - 70.4% 29.6% 0.0% 

1991 12,573 418 21.3 3410 138 - 69.6% 30.4% 0.0% 

1992 12,172 427 20.8 3512 145 - 68.6% 31.4% 0.0% 

1993 13,211 426 20.9 3519 147 - 67.6% 32.4% 0.0% 

1994 14,125 436 20.4 3603 152 - 61.9% 38.1% 0.0% 

1995 15,145 434 20.5 3613 158 - 63.5% 36.5% 0.0% 

1996 13,144 435 20.4 3659 164 - 62.2% 37.8% 0.0% 

1997 14,458 441 20.2 3727 169 - 60.1% 39.9% 0.0% 

1998 14,456 442 20.1 3744 171 - 58.3% 41.7% 0.0% 

1999 15,215 451 19.7 3835 179 - 58.3% 41.7% 0.0% 

2000 16,571 450 19.8 3821 181 - 58.8% 41.2% 0.0% 

2001 15,605 453 19.6 3879 187 - 58.6% 41.4% 0.0% 

2002 16,115 457 19.5 3951 195 - 55.3% 44.7% 0.0% 

2003 15,773 454 19.6 3999 199 - 53.9% 46.1% 0.0% 

2004 15,709 461 19.3 4111 211 - 52.0% 48.0% 0.0% 

2005 15,892 447 19.9 4059 209 - 55.6% 44.4% 0.0% 

2006 15,104 442 20.1 4067 213 - 57.9% 42.1% 0.0% 

2007 15,276 431 20.6 4093 217 - 58.9% 41.1% 0.0% 

2008 13,898 424 21.0 4085 219 48.9 59.3% 40.7% 0.0% 

2009 9,315 397 22.4 3914 208 48.1 67.0% 33.0% 0.0% 

2010 11,110 394 22.6 4002 214 48.6 62.7% 37.3% 0.0% 

2011 12,003 398 22.4 4127 230 49.5 57.8% 42.2% 0.1% 

2012 13,438 376 23.6 3977 222 48.8 64.4% 35.6% 0.4% 

2013 14,846 369 24.1 4015 227 49.2 63.2% 36.8% 0.7% 

2014 (prelim) - 367 24.2 4072 233 49.2 61.3% 38.7% -

1 Adjusted CO2 and fuel economy values reflect real world performance and are not comparable to automaker standards compliance levels. 

Adjusted CO2 values are, on average, about 25% higher than the unadjusted, laboratory CO2 values that form the starting point for GHG 

5 

standards compliance, and adjusted fuel economy values are about 20% lower, on average, than unadjusted fuel economy values. 2 0-to-60 Time has been deleted from this table; see Section 3.D for a new methodology for calculating 0-to-60 acceleration time. 
 

 

 

 

 

C. OVERVIEW OF LONG-TERM TRENDS 

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. This is because: 1) year-to-year 

variability can reflect short-term trends (two examples are the Cash for Clunkers rebates in 

2009 and the impact of the tsunami aftermath on Japan-based manufacturers in 2011) that 

may not be meaningful from a long-term perspective, and 2) the magnitude of year-to-year 

changes in annual CO2 emissions and fuel economy tend to be small relative to longer, multiyear trends. 

Figures 2.1 and 2.2 show fleetwide adjusted CO2 emissions and fuel economy from Table 2.1 

for MY 1975-2014. For both figures, the individual data points represent annual values, and 

the curves represent 3-year moving averages (where each year represents the average of that 

model year, the model year prior, and the model year following, e.g., the value for MY 2012 

represents the average of MY 2011-2013) which “smooth out” the year-to-year volatility. The 

two curves are essentially inversely proportional to each other, i.e., vehicle tailpipe CO2 

emissions (grams per mile) are proportional to fuel consumption (gallons per mile), which is 

the reciprocal of fuel economy (miles per gallon). 

Figure 2.1 

Adjusted CO2 Emissions by Model Year 

390 

440 

490 

540 

590 

640 

690 

Adjusted CO2 Emissions (g/mi) 

340 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Annual Value 

3-year Moving 

Average 

Model Year 

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Figure 2.2 

Adjusted Fuel Economy by Model Year 

26 

Adjusted Fuel Economy (MPG) 

24 

22 

20 

18 

16 

14 

12 

Annual Value 

3-year Moving 

Average 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

These two figures show that fleetwide adjusted CO2 emissions and fuel economy have 

undergone four clearly defined phases since 1975. 

Long-Term CO2 Emissions and Fuel Economy Phases: 

• Rapid improvements from MY 1975 through MY 1981, with fleet wide adjusted CO2 emissions decreasing by 

36% and fuel economy increasing by 56% over those six years 

• Slower improvements from MY 1982 through MY 1987 

• A slow, but steady reversal of improvements from MY 1988 through MY 2004, with CO2 emissions increasing by 

14% and fuel economy decreasing by 12%, even as technology innovation continued to evolve 

• A very favorable trend beginning in MY 2005, with annual CO2 emissions and fuel economy improvements in 

eight of the nine individual years, and with CO2 emissions decreasing by 20% and fuel economy increasing by 

25% since MY 2004 

Figure 2.3 shows fleetwide adjusted fuel economy, weight, and horsepower data for MY 1975-

2014 from Table 2.1. All of the data in Figure 2.3 are presented as percentage changes since 

1975. Vehicle weight and horsepower are critical vehicle attributes in that higher values, other 

things being equal, generally increase CO2 emissions and decrease fuel economy for 

conventional gasoline and diesel vehicles. 

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Figure 2.3 

Adjusted Fuel Economy, Weight, and Horsepower by Model Year 

100%
 

80%
 

Percent Change Since 1975 

60% 

40% 

20% 

0% 

−20% 

−40% 

Adjusted Fuel Economy 

Horsepower 

Weight 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

Figure 2.3 shows some very significant long-term trends. Both average vehicle weight and 

horsepower decreased in the late 1970s as fuel economy increased. During the two decades 

from the mid-1980s to the mid-2000s, vehicle weight and horsepower rose consistently and 

significantly, while fleetwide fuel economy slowly and steadily decreased. It is clear from 

Figure 2.3 that the considerable technology innovation during these two decades, on a fleetwide basis, supported attributes such as vehicle weight and power (and associated utility 

functions such as vehicle size, acceleration performance, safety features and content), but did 

not improve fuel economy. Since MY 2005, new automotive technology has improved both 

fuel economy and power, while keeping vehicle weight relatively constant. As a result, recent 

vehicles have greater acceleration performance, higher fuel economy, and lower CO2 

emissions. 

Table 2.1 also shows data for vehicle footprint. Footprint is a critical vehicle attribute since it 

is the basis for current and future GHG emissions and fuel economy standards. The Trends 

database includes footprint data from informal, external sources beginning in MY 2008, but 

because formal footprint data has only been provided by automakers since MY 2011, it is 

impossible to discern any long-term footprint trends at this time. 

Table 2.1 no longer includes 0-to-60 time acceleration data, which are not provided by 

automakers and are calculated by EPA using equations from the literature. See Section 3 for a 

discussion of a new methodology for calculating 0-to-60 acceleration time projections, as well 

as for more detail on weight, horsepower, and footprint data. 

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Table 2.1 also shows that truck share increased consistently from 1980 through 2004. The 

truck share increases from 1988 through 2004 were a critical underlying factor in the increase 

in fleetwide weight and power discussed above, as well as in the higher fleetwide CO2 

emissions and lower fleetwide fuel economy over that same period. Since 2004, truck share 

has been volatile, affected by factors such as the economic recession of 2009, the Car 

Allowance Rebate System (also known as Cash for Clunkers) in 2009, and the aftermath of 

the earthquake and tsunami in Japan in 2011. For more data and discussion of relative 

car/truck production share, as well as data for the separate car and truck fleets, see Section 3. 

Table 2.2 shows a comparison, for fuel economy and several other key attributes, of final MY 

2013 data with MY 2008 and MY 2004 data. 

MY 2008 is selected for comparison for three reasons: 1) five years provide a sufficient time to 

see meaningful multi-year trends, 2) it preceded a multi-year period of variability beginning in 

MY 2009, and 3) there have only been relatively minor changes in key vehicle attributes that 

influence fuel economy in the five years that followed. From MY 2008 to MY 2013, weight 

decreased by 1.7% (which would be expected to result in a slight increase in fuel economy, 

other things being equal), while horsepower increased by 3.7% (which would be expected to 

result in a slight decrease in fuel economy), so these two impacts counter balance to some 

degree. Footprint remained essentially unchanged. Fuel economy, on the other hand, 

increased by 3.1 mpg, or 15%, from MY 2008 to MY 2013. 

MY 2004 is shown in Table 2.2 primarily because it is the “valley year,” i.e., it is the year with 

the lowest adjusted fuel economy since MY 1980 and therefore now represents a 33-year low. 

As with the comparison of MY 2008 and MY 2013 above, the changes in weight and 

horsepower from MY 2004 to MY 2013 have gone in opposite directions—weight has 

decreased by 2.3% and horsepower has increased by 7.6%. We do not have footprint data for 

MY 2004. From MY 2004 to MY 2013, fuel economy has increased by 4.8 mpg, or 25%. 

These fuel economy increases of 15% since MY 2008 and 25% since MY 2004 are the largest 

of the last 30 years. As shown in Table 2.1, the only other period with a greater and more 

rapid fuel economy increase was from MY 1975 through MY 1981. 

Table 2.2 also shows fuel savings that would accrue to consumers who owned and operated 

average MY 2013 vehicles relative to MY 2008 and MY 2004 vehicles. Table 2.2 is based on 

the assumptions used to generate the 5-year savings/cost values shown on current Fuel 

Economy and Environment Labels: consumer operates the new vehicle for five years, 

averaging 15,000 miles per year, gasoline prices of $3.50 per gallon, and no discounting to 

reflect the time value of money (of course, people can drive more or less miles per year and 

gasoline prices can vary significantly). As shown in Table 2.2, the 3.1 mpg increase in average 

fuel economy from MY 2008 to MY 2013 would save a typical consumer $1600 over five years, 

and the 4.8 mpg increase from MY 2004 to MY 2013 would save the same consumer $2700. 

9 
 

 

 

 

 

 

 

 

 

Table 2.2 

Comparison of MY 2013 with MY 2008 and MY 2004* 

MY 2013 Relative to MY 2008 

Adjusted 

Fuel Economy 

5-Year 

Fuel Savings Weight Horsepower Footprint 

+3.1 MPG +15% $1,600 

MY 2013 R

-1.7% 

e

+3.8% 

lative to MY 2004 

+0.6% 

Adjusted 

Fuel Economy 

5-Year 

Fuel Savings Weight Horsepower Footprint 

+4.8 MPG +25% $2,700 -2.3% +7.8% -

*Note: some of the % values in this table may differ slightly from calculations
 

based on the absolute values in Table 2.1 due to rounding.
 

Figure 2.4 shows the production-weighted distribution of adjusted fuel economy by model 

year, for gasoline (including conventional hybrids) and diesel vehicles (excluding alternative 

fuel vehicles). It is important to note that the methodology used in this report for calculating 

adjusted fuel economy values has changed over time (see Section 10 for a detailed 

explanation). For example, the adjusted fuel economy for a 1980s vehicle in the Trends 

database is somewhat higher than it would be if the same vehicle were being produced today as 

the methodology for calculating adjusted values has changed over time to reflect real world 

vehicle operation. These changes are small for most vehicles, but larger for extremely-high fuel 

economy vehicles. For example, the “Best Car” line in Figure 2.4 for MY 2000 through MY 

2006 represents the original Honda Insight hybrid, and the several miles per gallon decrease 

over that period is primarily due to the change in methodology for adjusted fuel economy 

values, with just a 1 mpg decrease due to minor vehicle design changes during that time. 

Figure 2.4 

Adjusted Fuel Economy Distribution by Model Year 

Car Truck 

Adjusted Fuel Economy (MPG) 

0 

10 

20 

30 

40 

50 

60 

70 

1975 1980 1985 1990 1995 2000 2010 2005 2015 1975 1980 1985 1990 1995 2000 2005 2010 2015 

Bottom 

25% 

Top 

25% 

Bottom 

25% 

Top 

25% 

Worst Car 

Best Car 

Worst 5% 

Worst Truck 

Best Truck 

50% of Cars 

Best 5% 

Worst 5% 

50% of Trucks 

Best 5% 

First Hybrid 

Car 

Model Year 

10 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Since 1975, half of car production has consistently been within several mpg of each other. 

The fuel economy difference between the least efficient and most efficient car increased from 

about 20 mpg in MY 1975 to nearly 50 mpg in MY 1986 (when the most efficient car was the 

General Motors Sprint ER) and in MY 2000 (when the most efficient car was the original 

Honda Insight hybrid), and is now about 40 mpg. Hybrids have defined the “Best Car” line 

since MY 2000. The ratio of the highest-to-lowest fuel economy has increased from about 

three-to-one in MY 1975 to nearly five-to-one today, as the fuel economy of the least fuel 

efficient cars has remained roughly constant in comparison to the most fuel efficient cars 

whose fuel economy has nearly doubled since MY 1975. 

The overall fuel economy distribution for trucks is narrower than that for cars, with a peak in 

the fuel economy of the most efficient truck in the early 1980s when small pickup trucks 

equipped with diesel engines were sold by Volkswagen and General Motors. As a result, the 

fuel economy range between the most efficient and least efficient truck peaked at about 25 

mpg in the early 1980s. The fuel economy range for trucks then narrowed, and is now about 

20 mpg. Like cars, half of the trucks built each year have always been within a few mpg of 

each year's average fuel economy value. 

All of the above data are adjusted, combined city/highway CO2 emissions and fuel economy 

values for the combined car and truck fleet. Table 10.1 provides, for the overall car and truck 

fleets, adjusted and unadjusted, laboratory values for city, highway, and combined 

city/highway. Appendices B and C provide more detailed data on the distribution of adjusted 

fuel economy values by model year. 

Table 2.3 shows the highest fuel economy gasoline and diesel vehicles for the MY 1975-2014 

time frame (while the Trends report database began in MY 1975, we are confident that these 

are also the highest fuel economy values of all time for mainstream vehicles in the U.S. 

market). Note that alternative fuel vehicles, such as electric and plug-in hybrid electric 

vehicles, are excluded from this table (see Section 7 for information on alternative fuel 

vehicles). See Appendix A for a listing of the highest and lowest fuel economy vehicles, based 

on unadjusted fuel economy values, for each year since 1975. 

Unadjusted, laboratory fuel economy (weighted 55% city/45% highway) values are used to 

rank vehicles in Table 2.3, since the test procedures and methodology for determining 

unadjusted, laboratory fuel economy values have remained largely unchanged since 1975. 

Accordingly, unadjusted, laboratory values provide a more equitable fuel economy metric, 

from a vehicle design perspective, over the historical time frame, than the adjusted fuel 

economy values used throughout most of this report, as the latter also reflect changes in real 

world driving behavior such as speed, acceleration, and use of air conditioning. 

For Table 2.3, vehicle models with the same powertrain and essentially marketed as the same 

vehicle to consumers are shown only once, as are “twins” where very similar vehicle designs are 

marketed by two or more makes or brands. Models are typically sold for several years before 

being redesigned, so the convention for models with the same fuel economy for several years is 

11 
 

 

 

 

 

 

 

 

 

 

to show MY 2014, if applicable, and otherwise to show the first year when the model achieved 

its maximum fuel economy. Data are also shown for number of seats and inertia weight class. 

Table 2.3 

Top Ten Highest Unadjusted, Laboratory Fuel Economy Gasoline/Diesel Vehicles Since 1975 

Unadjusted, 

Laboratory 

Combined Inertia 

Model Fuel Economy Number Weight 

Year Manufacturer Model Powertrain (MPG) of Seats Class (lbs) 

2000 Honda Insight Gasoline Hybrid 76 2 2000 

2014 Toyota Prius Gasoline Hybrid 71 5 3500 

2014 Toyota Prius c Gasoline Hybrid 71 5 2750 

2014 Toyota/Lexus CT 200h Gasoline Hybrid 71 5 3500 

2014 Honda Accord Gasoline Hybrid 70 5 4000 

1986 GM/Chevrolet Sprint ER Conv. Gasoline 67 4 1750 

1994 GM/Geo Metro XFi Conv. Gasoline 66 4 1750 

1986 Honda Civic CRX HF Conv. Gasoline 64 2 2000 

2014 Honda Civic Gasoline Hybrid 64 5 3000 

2014 VW Jetta Gasoline Hybrid 61 5 3500 

As expected, all of the vehicles listed in Table 2.3 are cars. Somewhat more surprisingly, no 

diesel cars made the list.3 The top fuel economy vehicle is the MY 2000 Honda Insight, a twoseater that was the first hybrid vehicle sold in the U.S. market. The MY 2000 Insight had an 

unadjusted, laboratory value of 76 mpg, 5 mpg higher than the MY 2014 Toyota Prius, Prius c, 

and Lexus CT 200h vehicles, all of which have unadjusted, laboratory fuel economy values of 

71 mpg. The MY 2014 Honda Accord hybrid has a 70 mpg unadjusted, laboratory fuel 

economy value. 

Six of the highest ten fuel economy gasoline and diesel vehicles of all time are on the market 

in MY 2014, and all of these are conventional hybrids. Other than the MY 2000 Insight, also 

a conventional hybrid, the remaining three vehicles in Table 2.3 are non-hybrid gasoline 

vehicles from the late 1980s and early 1990s. The non-hybrid vehicle with the highest fuel 

economy is the 1986 Chevrolet Sprint ER with an unadjusted, laboratory fuel economy of 67 

mpg. 

One of the most important lessons from Table 2.3 is that there are important differences 

between the highest fuel economy vehicles of the past and those of today. All of the pre-MY 

2014 vehicles in Table 2.3 had 2 or 4 seats, while the MY 2014 vehicles all seat 5 passengers. 

The older vehicles had inertia weight class values of 1750-2000 pounds, while the MY 2014 

vehicles are in inertia weight classes of 2750-4000 pounds, or 1000-2000 pounds heavier. 

3 The most fuel efficient diesel car in the historical Trends database is the Nissan Sentra from the mid-1980s which had an unadjusted, 

laboratory fuel economy of 56 mpg. Volkswagen has sold several diesel cars with unadjusted, laboratory fuel economy values in excess of 

50 mpg. The most efficient MY 2014 diesel car is the BMW 328d, which has an unadjusted, laboratory value of 50 mpg. 

12 
 

 

 

 

 

 

 

 

 

Though not shown in Table 2.3, the MY 2014 vehicles also have faster acceleration rates and 

are also required to meet more stringent EPA health-related emissions standards and DOT 

safety standards than vehicles produced in the earlier model years. One clear conclusion from 

Table 2.3 is that conventional hybrid technology has enabled manufacturers to offer high fuel 

economy vehicles with much greater utility, while simultaneously meeting more stringent 

emissions and safety standards, than the high fuel economy vehicles of the past. 

Finally, since all of the vehicles in Table 2.3 are cars, Table 2.4 shows a comparable table for 

the highest fuel economy gasoline and diesel trucks since MY 1975. The methodological 

approach for selecting the trucks shown in Table 2.4 is the same as discussed above for cars in 

Table 2.3. The most fuel efficient gasoline/diesel truck in the historical Trends database is a 

small Volkswagen diesel pickup truck sold in the early 1980s with an unadjusted, laboratory 

fuel economy of 45 mpg. Interestingly, this small pickup truck had the same number of seats, 

and nearly the same inertia weight class, as the most fuel efficient car in Table 2.3, the 2000 

Honda Insight. The three other trucks with unadjusted, laboratory fuel economy values greater 

than 40 mpg are the early 1980s GM diesel 2WD pickups, the early 1980s Grumman Olson 

Kubvan, and the 2014 Subaru XV Crosstrek AWD. Six of the trucks in Table 2.4 are twopassenger diesel pickup trucks from the 1980s, and the remaining four trucks are recent model 

year gasoline hybrid SUVs. As with Table 2.3 for cars, gasoline hybrid technology has enabled 

automakers to offer high fuel economy vehicles with greater seating capacity and inertia weight 

than the high fuel economy diesel trucks of the early 1980s, while simultaneously meeting 

more stringent emissions and safety standards. 

Table 2.4 

Top Ten Highest Unadjusted, Laboratory Fuel Economy Gasoline/Diesel Trucks Since 1975 

Unadjusted, 

Laboratory 

Combined Inertia 

Model Fuel Economy Number Weight 

Year Manufacturer Model Powertrain (MPG) of Seats Class (lbs) 

1980 VW Pickup 2WD Diesel 45 2 2250 

1982 GM Pickup 2WD Diesel 43 2 2750 

1983 Grumman Olson Kubvan Diesel 42 2 2250 

2014 Subaru XV Crosstrek AWD Gasoline Hybrid 41 5 3500 

2010 Ford Escape Gasoline Hybrid 39 5 4000 

2014 Toyota Highlander AWD Gasoline Hybrid 39 8 5000 

2014 Toyota/Lexus RX 450h AWD Gasoline Hybrid 39 5 5000 

1984 Toyota Truck 2WD Diesel 38 2 3000 

1984 GM S10 Pickup 2WD Diesel 38 2 3000 

1983 Chrysler/Mitsubishi Ram 50/Pickup 2WD Diesel 38 2 3000 

13 
 

I 

 

 

 

 

 

 

 

 

 

 

 

Vehicle Class, Type, 

and Attributes 

A. VEHICLE CLASS 

We use “class” to refer to the overall division of light-duty (or personal) vehicles into the two 

classes of “cars” and “trucks.” This car-truck distinction has been recognized since the 

database was originally created in 1975, though the precise definitions associated with these 

two classes have changed somewhat over time. Car-truck classification is important both 

because of functional differences between the design of many cars and trucks, and because 

there are now separate footprint-based CO2 emissions and fuel economy standards curves for 

cars and trucks. The regulatory challenge has been where to draw the line between cars and 

trucks, and this has evolved over time. 

Car and truck classifications in this report are based on the current regulatory definitions used 

by both EPA and NHTSA for CO2 emissions and CAFE standards. These current definitions 

are somewhat different than those used in older versions of this report. The most important 

recent change was re-classification of many small and mid-sized, 2-wheel drive sport utility 

vehicles (SUVs) from the truck category to the car category. As with other such changes in this 

report, this change has been propagated back throughout the entire historical database. This 

re-classification reduced the absolute truck share by approximately 10% for recent years. A 

second recent change was the inclusion of medium-duty passenger vehicles (MDPVs), those 

SUVs and passenger vans with gross vehicle weight ratings between 8,500 and 10,000 pounds 

and which previously had been treated as heavy-duty vehicles, into the light-duty truck 

category. This is a far less important change, since the number of MDPVs is much smaller 

than it once was (e.g., only 6,500 MDPVs were sold in MY 2012). In this report, “cars” 

include passenger cars and most small and mid-sized, 2 wheel-drive SUVs, while “trucks” 

include all other SUVs and all minivans and vans, and pickup trucks below 8500 pounds gross 

vehicle weight rating. 

Figure 3.1 shows the car and truck production volume shares using the current car-truck 

definitions throughout the MY 1975-2014 database. 

14 
 

 

 

 

 

Figure 3.1 

Car and Truck Production Share by Model Year 

100% 

Production Share

75% 

50% 

25% 

0% 

Truck 

Car 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

Truck share was around 20% from MY 1975-1982, and then started to increase steadily 

through MY 2004, when it peaked at 48%. The truck share increases from MY 1988-2004, a 

period during which inflation-adjusted gasoline prices remained at or near historical lows, 

were a critical factor in the increased fleetwide CO2 emissions and decrease in fleetwide fuel 

economy over that same period. Since 2004, truck share has been volatile, affected by factors 

such as the economic recession of 2009, the Car Allowance Rebate System (also known as 

Cash for Clunkers) in 2009, and the earthquake and tsunami aftermath in Japan in 2011. 

The final truck share value for MY 2013 is 37%, a 1 percentage point increase relative to MY 

2012 and 11 percentage points lower than the peak truck share of 48% in MY 2004. The 

preliminary MY 2014 truck market share is projected to increase to 39%. 

15 
 

 

 

 

 

 

B. VEHICLE TYPE 

We use vehicle “type” to refer to secondary divisions within the car and truck classes. Vehicle 

type is not relevant to standards compliance, as all cars (and, separately, all trucks) use the 

same footprint-CO2 emissions and footprint-fuel economy target curves, but we believe that 

certain vehicle type distinctions are illustrative and meaningful from both vehicle design and 

marketing perspectives. 

This report breaks the car class into two types—cars and car SUVs. The truck class is split into 

three types—truck SUVs, pickups, and minivans/vans. This is a simpler approach than that 

used in some older versions of this report. 

Figure 3.2 

Vehicle Classes and Types Used in This Report 

Personal 

vehicles 

Car 

class 

Car 

type 

Car SUV 

type 

Truck 

class 

Truck SUV 

type 

Pickup 

type 

Minivan/Van 

type 

For cars, pre-2013 versions of this report generally divided the car class into as many as 9 

types/sizes (Cars, Wagons, and Car SUVs, each further subdivided into small, medium, and 

large sizes based on interior volume). We no longer use wagons as a car type in this report. 

More importantly, we believe that interior volume (the sum of passenger volume and cargo 

volume, typically measured in cubic feet), the metric that was historically used to differentiate 

various car types and sizes, is not as informative as it once was. For example, Figure 3.3 shows 

vehicle production volume versus interior volume for car type vehicles for two years, MY 1978 

and MY 2014, for high-volume manufacturers. Figure 3.3 excludes alternative fuel vehicles. 

16 
17 

Figure 3.3 

Car Type Vehicle Production vs. Interior Volume for High Volume Manufacturers, MY 1978 and MY 

2014

The data in Figure 3.3 illustrate the “compression” in the range of interior volumes for car 

type vehicles since 1978 (2-seater cars are excluded from this figure as automakers do not 

provide interior volume data for 2-seaters and each bar represents a band of 5 cubic feet). In 

MY 1978, there were mainstream car type vehicles on the market with interior volumes 

ranging from about 70 cubic feet to about 160 cubic feet, with meaningful production volume 

at both ends of the spectrum. Today, mainstream offerings range from about 80 cubic feet to 

about 130 cubic feet (some 4-seat cars in the 55-60 cubic feet interior volume range do not 

show up in this figure due to very low production volume). The compression is even greater 

when considering production volumes. We reviewed the data for one high-volume make that 

offered seven car type models in MY 2012. The interior volume of these seven models ranged 

from 97-124 cubic feet, with 75% of sales within a very narrow interior volume range of 104-

111 cubic feet, and about 50% of production (representing 3 models) with essentially the same 

1978

2014

0

1,000,000

2,000,000

0

1,000,000

2,000,000

50 100 150 200

Interior Volume (sq ft)

Production
 

 

 

 

 

 

interior volume (110-111 cubic feet). 

Accordingly, we believe that interior volume is no longer very useful as a differentiator for the 

car types in the Trends database. We believe that vehicle footprint is a more appropriate 

indicator of car size because it is the basis for both CO2 emissions and fuel economy standards 

(and it is relevant to both cars and trucks). Interior volume data for car type vehicles will still 

be included in the Trends database. 

This report divides the car class into two types: 1) a car SUV type for those SUVs that must 

meet the car GHG emissions and fuel economy standards, and 2) a car type for all other 

vehicles in the car class, including the fueleconomy.gov designations of minicompact, 

subcompact, compact, midsize, large, two-seater cars, and station wagons. For propagating 

back in the historical database, station wagons are generally allocated to the car type. 

For trucks, pre-2013 versions of this report divided the truck class into 9 types/sizes (SUVs, 

Pickups, and Vans (including minivans), each further subdivided into small, medium, and 

large sizes based on vehicle wheelbase). This report retains the three historical truck types 

because we believe that there continue to be meaningful functional and marketing differences 

between truck SUVs (those SUVs that must meet the truck GHG emissions and fuel economy 

standards), pickups, and minivans/vans. See Section 10 for the definitions for SUVs, pickups, 

minivans, and vans and for more information about car-truck classifications. We use 

engineering judgment to allocate the very small number of special purpose vehicles (as 

designated on fuel economy.gov) to the three truck types. 

It is important to note that this report no longer uses wheelbase to differentiate between truck 

type sizes. The rationale for this change, similar to that for car interior volume above, is that 

the wheelbase metric is not as informative as it once was. For example, under the wheelbase 

thresholds that were used in the 2012 report, 99% of MY 2011 pickups were “large” and 99% 

of MY 2011 minivans/vans were “medium.” In addition, wheelbase is one of the two factors 

that comprise vehicle footprint (wheelbase times average track width). 

18 
 

 

Figure 3.4 shows the car and truck production volume shares for MY 1975-2014, subdivided 

into the two car types and three truck types. Table 3.1 shows the same data in tabular form. 

Figure 3.4 

Vehicle Type Production Share by Model Year 

100% 

Production Share 

75% 

50% 

25% 

0% 

Minivans/Vans 

Truck SUVs 

Pickups 

Cars 

Car SUVs 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

19 
 

 

 

 

Table 3.1 

Vehicle Type Production Share by Model Year 

Model Car Truck Minivans/ All 

Year Cars SUVs All Cars SUVs Pickups Vans Trucks 

1975 80.6% 0.1% 80.7% 1.7% 13.1% 4.5% 19.3% 

1976 78.8% 0.1% 78.9% 1.9% 15.1% 4.1% 21.1% 

1977 80.0% 0.1% 80.1% 1.9% 14.3% 3.6% 19.9% 

1978 77.3% 0.1% 77.5% 2.5% 15.7% 4.3% 22.5% 

1979 77.8% 0.1% 77.9% 2.8% 15.9% 3.5% 22.1% 

1980 83.5% 0.0% 83.5% 1.6% 12.7% 2.1% 16.5% 

1981 82.7% 0.0% 82.8% 1.3% 13.6% 2.3% 17.2% 

1982 80.3% 0.1% 80.5% 1.5% 14.8% 3.2% 19.5% 

1983 77.7% 0.3% 78.0% 2.5% 15.8% 3.7% 22.0% 

1984 76.1% 0.4% 76.5% 4.1% 14.6% 4.8% 23.5% 

1985 74.6% 0.6% 75.2% 4.5% 14.4% 5.9% 24.8% 

1986 71.7% 0.4% 72.1% 4.6% 16.5% 6.8% 27.9% 

1987 72.2% 0.6% 72.8% 5.2% 14.4% 7.5% 27.2% 

1988 70.2% 0.7% 70.9% 5.6% 16.1% 7.4% 29.1% 

1989 69.3% 0.7% 70.1% 5.7% 15.4% 8.8% 29.9% 

1990 69.8% 0.5% 70.4% 5.1% 14.5% 10.0% 29.6% 

1991 67.8% 1.8% 69.6% 6.9% 15.3% 8.2% 30.4% 

1992 66.6% 2.0% 68.6% 6.2% 15.1% 10.0% 31.4% 

1993 64.0% 3.6% 67.6% 6.3% 15.2% 10.9% 32.4% 

1994 59.6% 2.3% 61.9% 9.1% 18.9% 10.0% 38.1% 

1995 62.0% 1.5% 63.5% 10.5% 15.0% 11.0% 36.5% 

1996 60.0% 2.2% 62.2% 12.2% 14.9% 10.7% 37.8% 

1997 57.6% 2.5% 60.1% 14.5% 16.7% 8.8% 39.9% 

1998 55.1% 3.1% 58.3% 14.7% 16.7% 10.3% 41.7% 

1999 55.1% 3.2% 58.3% 15.4% 16.7% 9.6% 41.7% 

2000 55.1% 3.7% 58.8% 15.2% 15.8% 10.2% 41.2% 

2001 53.9% 4.8% 58.6% 17.3% 16.1% 7.9% 41.4% 

2002 51.5% 3.7% 55.3% 22.3% 14.8% 7.7% 44.7% 

2003 50.2% 3.6% 53.9% 22.6% 15.7% 7.8% 46.1% 

2004 48.0% 4.1% 52.0% 25.9% 15.9% 6.1% 48.0% 

2005 50.5% 5.1% 55.6% 20.6% 14.5% 9.3% 44.4% 

2006 52.9% 5.0% 57.9% 19.9% 14.5% 7.7% 42.1% 

2007 52.9% 6.0% 58.9% 21.7% 13.8% 5.5% 41.1% 

2008 52.7% 6.6% 59.3% 22.1% 12.9% 5.7% 40.7% 

2009 60.5% 6.5% 67.0% 18.4% 10.6% 4.0% 33.0% 

2010 54.5% 8.2% 62.7% 20.8% 11.5% 5.0% 37.3% 

2011 47.7% 10.1% 57.8% 25.6% 12.3% 4.3% 42.2% 

2012 54.9% 9.4% 64.4% 20.6% 10.1% 4.9% 35.6% 

2013 53.3% 9.9% 63.2% 22.4% 10.6% 3.8% 36.8% 

2014 51.3% 10.0% 61.3% 23.3% 11.5% 3.9% 38.7% 

The data from Table 3.1 show that car type market share has dropped from around 80% in 

the MY 1975-1985 timeframe to about 50% today. Pickups accounted for most of the 

remaining market share in MY 1975-1985. In the late 1980s, both minivans/vans and truck 

SUVs began to erode car type market share, with truck SUV market share reaching as high as 

20 
 

 

 

 

 

 

 

26% in MY 2004 and MY 2011, before declining slightly to about 23% today. More recently, 

car SUVs have increased market share to about 10%. Total SUVs, including both car SUVs 

and truck SUVs, have achieved market share in the 30-35% range over the last few years. 

Pickup market share was approximately 15% from MY 1975 through MY 2005, but has 

declined to about 11% today. 

One particular trend of interest is associated with small SUVs that are classified as cars if they 

have 2-wheel drive and as trucks if they have 4-wheel drive. For this analysis summarized in 

Table 3.2, we reviewed MY 2000-2014 SUVs with inertia weights of 4000 pounds or less 

(SUVs with inertia weights in excess of 4000 pounds are typically categorized as trucks 

regardless of whether they are 2-wheel or 4-wheel drive). Note that we have propagated the 

current car-truck definitions back to previous years in the Trends database in order to 

maintain the integrity of historical trends (i.e., some vehicles that were defined as trucks in 

past years are now defined as cars for those same years in the Trends database). 

Table 3.2 

Car-Truck Classification of SUVs with Inertia Weights of 4000 Pounds or Less 

Car SUV Percent 

Model Production Truck SUV Total SUV Percent Truck 

Year (000) Production Production Car SUV SUV 

2000 617 796 1,413 43.7% 56.3% 

2001 743 920 1,663 44.7% 55.3% 

2002 603 928 1,531 39.4% 60.6% 

2003 575 994 1,569 36.6% 63.4% 

2004 599 1,116 1,715 34.9% 65.1% 

2005 753 867 1,620 46.5% 53.5% 

2006 691 758 1,449 47.7% 52.3% 

2007 761 843 1,604 47.4% 52.6% 

2008 748 799 1,547 48.4% 51.6% 

2009 539 575 1,115 48.4% 51.6% 

2010 659 854 1,512 43.5% 56.5% 

2011 985 1,044 2,029 48.5% 51.5% 

2012 1,043 869 1,912 54.6% 45.4% 

2013 1,134 1,205 2,338 48.5% 51.5% 

2014 - - - 52.5% 47.5% 

Table 3.2 shows that the fraction of SUVs with curb weights less than 4000 pounds that are 

classified as trucks, using the current car-truck definitions propagated back in time, has been 

declining somewhat over the last decade, from around 60% in the early 2000s to around 50% 

in recent years. 

Appendix D gives additional data stratified by vehicle type. 

21 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C. VEHICLE FOOTPRINT, WEIGHT, AND 

HORSEPOWER 

This sub-section focuses on three key attributes that impact CO2 emissions and fuel economy. 

These attributes are footprint, weight, and horsepower. All three attributes are relevant to all 

light-duty vehicles and were included in the Table 2.1 fleetwide data. Vehicle acceleration is 

discussed in the following sub-section. 

Vehicle footprint is a very important attribute since it is the basis for the current CO2 

emissions and fuel economy standards. Footprint is the product of wheelbase times average 

track width (or the area defined by where the centers of the tires touch the ground). We 

provide footprint data beginning with MY 2008, though it is important to highlight that we 

have higher confidence in the data beginning in MY 2011. Footprint data from MY 2008-

2010 were aggregated from various sources, some independent of formal automaker data, and 

EPA has less confidence in the consistency and precision of this data. Beginning in MY 2011, 

automakers began to formally submit reports to EPA with footprint data. With these caveats, 

Table 2.1 above shows that average fleetwide footprint has hovered around 49 square feet 

since MY 2008, with MY 2013 footprint of 49.2 square feet representing a 0.4 square foot 

increase relative to MY 2012. The preliminary MY 2014 footprint value is 49.2 square feet, 

which if realized would be unchanged from MY 2013. Future footprint trends will be a major 

topic of interest in future Trends reports as we continue to add to the formal data that we 

began to collect in MY 2011. 

Vehicle weight is a fundamental vehicle attribute, both because it can be related to utility 

functions such as vehicle size and features, and because higher weight, other things being 

equal, will increase CO2 emissions and decrease fuel economy. All Trends vehicle weight data 

are based on inertia weight class. Each inertia weight class represents a range of loaded vehicle 

weights, or vehicle curb weights plus 300 pounds. Vehicle inertia weight classes are in 250-

pound increments for inertia weight classes that are less than 3000 pounds, while inertia 

weight classes over 3000 pounds are divided into 500-pound increments. Table 2.1 shows that 

average fleetwide vehicle weight decreased from nearly 4100 pounds in MY 1976 to 3200 

pounds in MY 1981, likely driven by both increasing fuel economy standards (which, at that 

time, were universal standards, and not based on any type of vehicle attribute) and higher 

gasoline prices. Average vehicle weight then grew slowly but steadily over the next 23 years (in 

part because of the increasing truck share), to 4111 pounds in MY 2004. Since 2004, average 

vehicle weight has stayed fairly constant in the range of 4000 to 4100 pounds, reaching 4127 

pounds in MY 2011, an all-time high since the database began in 1975. Average MY 2013 

weight was 4015 pounds, a 38 pound increase relative to MY 2012. The preliminary MY 2014 

value for weight is 4072 pounds, which if realized would represent a 57 pound increase 

compared to MY 2013. 

Horsepower (hp) is of interest as a direct measure of vehicle power. In the past, higher power 

22 
 

 

 

 

generally increased CO2 emissions and decreased fuel economy, though this relationship is 

now less important with turbo and hybrid packages. Trends horsepower data for all gasoline 

(including conventional hybrids) and diesel vehicles in the Trends database reflect engine 

rated horsepower. Average fleetwide horsepower dropped from 137 hp in MY 1975 to 102 hp 

in MY 1981. Since MY 1981, horsepower values have increased just about every year (again, 

in part due to the increasing truck share through 2004), and current levels are over twice those 

of the early 1980s. Average MY 2013 horsepower was 227 hp, a 5 hp increase relative to MY 

2012. The preliminary value for MY 2014 is 233 hp, which, if achieved, would represent an 

all-time high. 

The following two tables provide data for the three attributes discussed above for the car and 

truck classes separately (these data are shown for the entire fleet in Table 2.1 above). 

Table 3.3.1 shows that car adjusted fuel economy reached an all-time record of 27.6 mpg in 

MY 2013, which is more than twice the MY 1975 level of 13.5 mpg. Car weight and footprint 

increased by less than 1% in MY 2013, while car horsepower increased by 3%. Car weight and 

horsepower are projected to increase slightly in MY 2014, while car footprint is projected to 

remain unchanged. The interior volume data shown in Table 3.3.1 is only for car type 

vehicles, as EPA does not collect interior volume data for car SUVs. 

23 
 

 

 

 

Table 3.3.1 

Car Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year4 

Gasoline 

and Diesel Car Adj Adj Fuel 

Model Production Production CO2 Economy Weight Footprint Interior 

Year (000) Share (g/mi) (MPG) (lb) HP (sq ft) Volume* 

1975 8,247 80.7% 661 13.5 4057 136 - -

1976 9,734 78.9% 598 14.9 4059 134 - -

1977 11,318 80.1% 570 15.6 3944 133 - 110 

1978 11,191 77.5% 525 16.9 3588 124 - 109 

1979 10,810 77.9% 517 17.2 3485 119 - 109 

1980 9,444 83.5% 446 20.0 3101 100 - 104 

1981 8,734 82.8% 418 21.4 3076 99 - 106 

1982 7,832 80.5% 402 22.2 3053 99 - 106 

1983 8,035 78.0% 403 22.1 3112 104 - 109 

1984 10,730 76.5% 397 22.4 3101 106 - 108 

1985 10,879 75.2% 387 23.0 3096 111 - 108 

1986 11,074 72.1% 375 23.7 3043 111 - 107 

1987 10,826 72.8% 374 23.8 3035 113 - 107 

1988 10,845 70.9% 369 24.1 3051 116 - 107 

1989 10,126 70.1% 376 23.6 3104 121 - 108 

1990 8,875 70.4% 382 23.3 3178 129 - 107 

1991 8,748 69.6% 382 23.3 3168 133 - 107 

1992 8,350 68.6% 389 22.9 3254 141 - 108 

1993 8,929 67.6% 386 23.0 3241 140 - 108 

1994 8,747 61.9% 386 23.0 3268 144 - 108 

1995 9,616 63.5% 382 23.3 3274 153 - 109 

1996 8,177 62.2% 384 23.1 3297 155 - 109 

1997 8,695 60.1% 384 23.2 3285 156 - 109 

1998 8,425 58.3% 386 23.0 3334 160 - 109 

1999 8,865 58.3% 392 22.7 3390 164 - 109 

2000 9,742 58.8% 395 22.5 3401 168 - 110 

2001 9,148 58.6% 393 22.6 3411 169 - 109 

2002 8,904 55.3% 390 22.8 3415 173 - 110 

2003 8,496 53.9% 386 23.0 3437 176 - 110 

2004 8,176 52.0% 389 22.9 3492 184 - 110 

2005 8,839 55.6% 384 23.1 3498 183 - 111 

2006 8,744 57.9% 386 23.0 3563 194 - 112 

2007 9,001 58.9% 375 23.7 3551 191 - 110 

2008 8,243 59.3% 372 23.9 3569 194 45.3 110 

2009 6,244 67.0% 356 25.0 3502 186 45.1 110 

2010 6,969 62.7% 346 25.7 3536 190 45.4 110 

2011 6,934 57.8% 348 25.6 3617 200 46.0 111 

2012 8,648 64.4% 329 27.0 3516 192 45.7 111 

2013 9,377 63.2% 322 27.6 3545 198 45.9 110 

2014 - 61.3% 320 27.9 3572 201 45.9 111 

*Interior volume calculated using "Car" type only. 

4 0-to-60 Time acceleration data has been deleted from this table; see Section 3.D for a discussion of a new methodology for calculating 0-to60 acceleration time projections. 

24 
 

 

 

Table 3.3.2 shows, for trucks only, the same data provided for cars in Table 3.3.1 above and 

for the overall light vehicle fleet in Table 2.1. Truck adjusted fuel economy was also a record 

high in MY 2013 at 19.8 mpg, which was a 0.5 mpg increase over MY 2012. Truck weight, 

horsepower, and footprint were all slightly higher in MY 2013. Truck fuel economy, weight, 

and horsepower are projected to increase in MY 2014, while truck footprint is projected to 

decline slightly. 

25 
 

 

Table 3.3.2 

Truck Adjusted CO2 Emissions, Adjusted Fuel Economy, and Key Parameters by Model Year5 

Gasoline 

and Diesel Truck Adj Adj Fuel 

Model Production Production CO2 Economy Weight Footprint 

Year (000) Share (g/mi) (MPG) (lb) HP (sq ft) 

1975 1,977 19.3% 764 11.6 4073 142 -

1976 2,600 21.1% 726 12.2 4155 141 -

1977 2,805 19.9% 669 13.3 4136 147 -

1978 3,257 22.5% 687 12.9 4152 146 -

1979 3,072 22.1% 711 12.5 4257 138 -

1980 1,863 16.5% 565 15.8 3869 121 -

1981 1,821 17.2% 523 17.1 3806 119 -

1982 1,901 19.5% 516 17.4 3813 120 -

1983 2,267 22.0% 504 17.7 3773 118 -

1984 3,289 23.5% 512 17.4 3787 118 -

1985 3,581 24.8% 509 17.5 3803 124 -

1986 4,291 27.9% 489 18.2 3741 123 -

1987 4,039 27.2% 486 18.3 3718 131 -

1988 4,450 29.1% 498 17.8 3850 141 -

1989 4,327 29.9% 506 17.6 3932 146 -

1990 3,740 29.6% 512 17.4 4014 151 -

1991 3,825 30.4% 500 17.8 3961 150 -

1992 3,822 31.4% 512 17.3 4078 155 -

1993 4,281 32.4% 507 17.5 4098 160 -

1994 5,378 38.1% 518 17.2 4149 166 -

1995 5,529 36.5% 524 17.0 4201 168 -

1996 4,967 37.8% 518 17.2 4255 179 -

1997 5,762 39.9% 528 16.8 4394 189 -

1998 6,030 41.7% 521 17.1 4317 188 -

1999 6,350 41.7% 535 16.6 4457 199 -

2000 6,829 41.2% 528 16.8 4421 199 -

2001 6,458 41.4% 538 16.5 4543 212 -

2002 7,211 44.7% 539 16.5 4612 223 -

2003 7,277 46.1% 533 16.7 4655 224 -

2004 7,533 48.0% 538 16.5 4783 240 -

2005 7,053 44.4% 526 16.9 4763 242 -

2006 6,360 42.1% 518 17.2 4758 240 -

2007 6,275 41.1% 512 17.4 4871 254 -

2008 5,656 40.7% 499 17.8 4837 254 54.0 

2009 3,071 33.0% 480 18.5 4753 252 54.0 

2010 4,141 37.3% 474 18.8 4784 253 53.8 

2011 5,069 42.2% 466 19.1 4824 271 54.4 

2012 4,791 35.6% 461 19.3 4809 276 54.5 

2013 5,469 36.8% 450 19.8 4822 277 54.7 

2014 - 38.7% 442 20.1 4866 282 54.4 

5 0-to-60 Time acceleration data has been deleted from this table; see Section 3.D for a discussion of a new methodology for calculating 0-

to-60 acceleration time projections. 

26 
 

 

 

 

 

 

 

 

Figure 3.5 includes summary charts showing long-term trends for adjusted CO2 emissions, 

adjusted fuel economy, footprint, weight, and horsepower for the five vehicle types discussed 

above. Most of the long-term trends are similar across the various vehicle types, with the major 

exception being pickups, for which CO2 emissions and fuel economy have not reached all-time 

records in recent years (unlike the other vehicle types) due to considerably greater increases in 

weight and horsepower relative to the other vehicle types. It is also noteworthy that truck 

SUVs have achieved the largest reduction in CO2 emissions since 2000, followed by car SUVs. 

Figure 3.5 

Adjusted CO2 Emissions, Adjusted Fuel Economy and Other Key Parameters by Vehicle Type 

10 

15 

20 

25 

Adjusted Fuel 

Economy (MPG) 

Footprint (sq ft) 

Weight (lb) 

Horsepower 

Car Car SUV Truck SUV Pickup Minivan/Van 

2500 

3000 

3500 

4000 

4500 

5000 

5500 

45 

50 

55 

60 

65 

100 

150 

200 

250 

300 

300 

400 

500 

600 

700 

800 

Adjusted CO2 

Emissions (g/mi) 

30 

6000 

350 

70 

197519801985199019952000200520102015197519801985199019952000200520102015197519801985199019952000200520102015197519801985199019952000200520102015

197519801985199019952000200520102015 

Model Year 

Figure 3.6 shows the annual production share of different inertia weight classes for cars and 

trucks. This figure again shows the “compression” on the car side that was also discussed with 

respect to interior volume—in the late 1970s there were significant car sales both in the <2750 

pound class as well as in the 5500 pound class (interestingly, there were more 5500 pound cars 

sold in the late 1970s than there were 5500 pound trucks). Today, both the lightest and 

heaviest cars have largely disappeared from the market, and over 95% of all cars are in just 

three inertia weight classes (3000, 3500, and 4000 pounds). Conversely, the heavy end of the 

27 
 

 

 

 

 

 

 

 

 

 

 

truck market has expanded markedly such that 4500 pounds and greater trucks now account 

for over 80% of the truck market. 

Figure 3.6 

Car and Truck Production Share by Vehicle Inertia Weight Class 

Car Truck 

Production Share 

100% Weight 

<2750 

2750 

75% 

50% 

25% 

0% 

3000 

3500 

4000 

4500 

5000 

5500 

6000 

>6000 

197519801985199019952000200520102015197519801985199019952000200520102015 

Model Year 

The next three figures, Figures 3.7 through 3.9, address the engineering relationships between 

efficiency and three key vehicle attributes: footprint, weight, and interior volume (car type 

only). It is important to emphasize that, in order to best reflect the engineering relationships 

involved, these figures differ from most of the figures and tables presented so far in three 

important ways. One, they show fuel consumption (the inverse of fuel economy), because fuel 

consumption represents a linear relationship while fuel economy is non-linear (i.e., a 1 mpg 

difference at a lower fuel economy represents a greater change in fuel consumption than a 1 

mpg difference at a higher fuel economy). The metric used for fuel consumption is gallons per 

100 miles, also shown on new vehicle Fuel Economy and Environment Labels. Fuel 

consumption is an excellent surrogate for CO2 emissions, as well. Two, Figures 3.7 through 

3.9 show unadjusted, laboratory values (for fuel consumption), rather than the adjusted 

values shown primarily in this report, in order to exclude the impact of non-technology factors 

associated with the adjusted fuel economy values (e.g., changes in driving speeds or use of air 

conditioning over time). Three, there is no sales weighting in either the calculations of the 

individual data points or the regression lines as the purpose of these figures is to illustrate the 

technical relationships between fuel consumption and key vehicle attributes, independent of 

market success. The non-hybrid gasoline, diesel, and gasoline hybrid data points in these 

figures are averages for each integer footprint value, are plotted separately to illustrate the 

differences between these technologies, and the regression lines are based on the non-hybrid 

gasoline data points only. As would be expected, the conventional hybrid and diesel data 

points almost always reflect lower fuel consumption that the regression line representing non28 
 

 

 

 

 

 

 

hybrid gasoline vehicles. 

Figure 3.7 shows unadjusted, laboratory fuel consumption as a function of vehicle footprint 

for the MY 2013 car and truck fleets. On average, higher footprint values are correlated with 

greater fuel consumption. Car fuel consumption is more sensitive to footprint (i.e., greater 

slope for the regression line based on conventional gasoline vehicles) than truck fuel 

consumption, though this relationship is exaggerated somewhat by the fact that the highest 

footprint cars are low-volume luxury cars with very high fuel consumption. Most cars have 

footprint values below 50-55 square feet, and at these footprint levels, the average car has 

lower fuel consumption than the average truck. For the much smaller number of cars that 

have footprint values greater than 55 square feet (typically performance or luxury cars), these 

cars generally have higher fuel consumption than trucks of the same footprint. 

Figure 3.7 

Unadjusted, Laboratory Fuel Consumption vs. Footprint, Cars and Trucks, MY 2013 

1 

2 

3 

4 

5 

6 

Gal / 100 miles 

30 40 50 60 70 80 30 40 50 60 70 80 

Car Truck 

Conventional 

Diesel 

Hybrid 

Footprint (sq ft) 

29 
 

 

 

 

 

 

Figure 3.8 shows unadjusted, laboratory fuel consumption as a function of vehicle inertia 

weight for the MY 1975 and MY 2013 car and truck fleets. On average, fuel consumption 

increases linearly with vehicle weight, and the regressions are particularly tight for the data 

points representing non-hybrid gasoline vehicles. In 1975, trucks consistently had higher fuel 

consumption than cars for a given weight, but in 2013, the differences were much smaller, and 

at 5000 pounds and above, the average car had higher fuel consumption than the average 

truck, again likely due to the fact that very heavy cars are typically luxury and/or performance 

vehicles with high fuel consumption. At a given weight, most cars and trucks have reduced 

their fuel consumption by about 50% since 1975, with the major exception being the heaviest 

cars which have achieved more modest reductions in fuel consumption. 

Figure 3.8 

Unadjusted, Laboratory Fuel Consumption vs. Inertia Weight, Cars and Trucks, MY 1975 and MY 

2013 

Car Truck 

Gal / 100 miles 

2000 4000 6000 8000 2000 4000 6000 8000 

2 

4 

6 

8 

10 

1975 

2013 

Conventional 

Diesel 

Hybrid 

Weight (lb) 

30 
 

 

 

 

 

 

 

 

Finally, Figure 3.9 shows unadjusted, laboratory fuel consumption as a function of interior 

volume for MY 1978 and 2013 for the car type only. This figure excludes two-seater cars, as 

interior volume data is not reported for two-seaters. The data for MY 1978 is much more 

scattered than that for MY 2013. The slope of the regression line for non-hybrid gasoline 

vehicles in 2013 is nearly flat, suggesting that there is no longer much of a relationship 

between interior volume and fuel consumption within the car type. This MY 2013 data 

further confirm the point made earlier in this section that interior volume is no longer a good 

attribute for differentiating within the car type. 

Figure 3.9 

Unadjusted, Laboratory Fuel Consumption vs. Car Type Interior Volume, MY 1978 and MY 

2013 

1978 2013 

0 100 150 100 150 

Gal / 100 miles 

0.0 

2.5 

5.0 

7.5 

10.0 

50 0 50 

1978 

2013 

Diesel 

Hybrid 

Conventional 

Volume (cu ft) 

31 
 

 

 

 

 

 

 

 

 

 

 

 

 

D. VEHICLE ACCELERATION 

Vehicle performance can be evaluated in many ways, including vehicle handling, braking, and 

acceleration. In the context of this report, acceleration is an important metric because there is 

a general correlation between how quickly a vehicle can accelerate and fuel economy. 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. There are other metrics that are relevant for evaluating vehicle acceleration, 

including the time to reach 30 miles per hour or the time to travel a quarter mile, but this 

section is limited to a discussion of 0-to-60 acceleration times and the methodology used to 

calculate 0-to-60 times. Acceleration times are calculated since this data is not reported by 

manufacturers to EPA, nor is there a comprehensive source. 

Trends in 0-to-60 Times 

Since the early 1980s, there has been a clear downward trend in 0-to-60 times. Figure 3.10 

shows the average new vehicle 0-to-60 acceleration time from MY 1978 to MY 2014 based on a 

calculation methodology described below. The average new vehicle in MY 2014 is projected to 

have a 0-to-60 time of about 8.2 seconds, which is the fastest average 0-to-60 time since the 

database began in 1975. Average vehicle horsepower has also substantially increased since MY 

1982, as shown in Figure 2.3, and clearly at least part of that increase in power has been 

focused on decreasing acceleration time (some has also been used to support larger, heavier 

vehicles). 

Figure 3.10 

Calculated 0-to-60 Acceleration Performance 

10.0 

12.5 

15.0 

1980 1985 1990 1995 2000 2005 2010 2015 

Seconds 

17.5 

7.5 

1975 

Model Year 

32 
 

 

The decreasing long-term trend in 0-to-60 times is consistent across all vehicle types, as shown 

in Figure 3.11. The trend of decreasing acceleration time appears to be slowing somewhat in 

recent years for cars, car SUVs, and truck SUVs. The opposite is true for pickup trucks, where 

calculated 0-to-60 times continue to steadily decrease. Pickups are generally designed to 

emphasize towing and hauling capabilities, while maintaining adequate driving performance. 

The continuing decrease in pickup truck 0-to-60 times is likely due to the increasing towing 

and hauling capacity of pickups, which decreases the calculated 0-to-60 times of pickups. 

Figure 3.11 

Acceleration Performance by Vehicle Type 

7.5 

10.0 

12.5 

15.0 

17.5 

7.5 

10.0 

12.5 

15.0 

17.5 

7.5 

10.0 

12.5 

15.0 

17.5 

7.5 

10.0 

12.5 

15.0 

17.5 

Car 

Car SUV 

Truck SUV 

Pickup 

Minivan/Van 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Seconds 

7.5 

10.0 

12.5 

15.0 

17.5 

Model Year 

Vehicle acceleration is determined by many factors, including weight, horsepower, 

transmission design, engine technologies, and body style. The impacts of these, and other 

33 
 

 

 

 

 

 

 

 

 

 

 

factors, on 0-to-60 times have been evaluated in the literature (MacKenzie, 2012). Many of the 

same factors that affect acceleration also influence vehicle fuel economy, the result being a 

general correlation between faster 0-to-60 times and lower fuel economy. All other things 

equal, a vehicle with more power will likely have faster 0-to-60 acceleration and lower fuel 

economy. However, there are factors that can improve both 0-to-60 acceleration and fuel 

economy, such as reducing weight. 

Acceleration remains an important parameter that will be tracked in this report to evaluate 

vehicle performance. The 0-to-60 metric is only one of many performance metrics (e.g. 

stopping distance, skid pad g’s, lane change maneuver speed, etc.), but it remains an important 

parameter that will be tracked in this report due to its strong association with vehicle fuel 

economy and emissions. 

Methodology for Calculating 0-to-60 Times 

Unlike most of the data presented in this report, 0-to-60 times are based on calculations and 

not data submitted to the EPA by manufacturers. The 0-to-60 metric is a very commonly used 

automotive metric, however there is no standard method of measuring 0-to60 times. Nor, to 

our knowledge, is there a complete published list of measured vehicle 0-to-60 acceleration 

times. This report relies on calculated 0-to-60 times based on published methodologies. This 

year, the report is changing to a newer and more accurate methodology. 

This report has long reported 0-to-60 acceleration times for conventional gasoline vehicles 

calculated from vehicle weight and horsepower data reported to EPA. Past versions of this 

report calculated 0-to-60 acceleration times for conventional gasoline vehicles based on the 

following equation: 

t = F (HP/WT)-f 

where t is acceleration time; HP and WT reflect Trends data for horsepower and weight, 

respectively; and the coefficients F and f are empirical parameters determined in the literature 

by obtaining a least-squares fit for available test data. This approach uses .892 and .805 for the 

F and f coefficients, respectively, for vehicles with automatic transmissions and .967 and .775, 

respectively, for those with manual transmissions (Malliaris 1976). Since the equation form 

and coefficients were developed for vehicles with conventional gasoline powertrains, we have 

used published values from external sources to estimate 0-to-60 acceleration time for vehicles 

with hybrid powertrains or diesel engines. Given that the above equation and coefficients were 

initially developed in the 1970s, there has been increasing concern that the calculated 0-to-60 

acceleration times associated with this methodology may not be representative of actual vehicle 

performance. 

A recent study presented a much more in depth methodology for calculating 0-to-60 times. 

Mackenzie (MacKenzie 2012) used actual 0-to-60 test results from Consumer Reports, 

spanning from MY 1975 to MY 2010. This new approach includes weight and horsepower, 

34 

but also captures the effects of many additional parameters, including engine type, 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

transmission type, number of transmission gears, drive type, and body style. The results 

include estimates of fixed effects for each year to account for technology changes over time 

and for factors not directly accounted for in the defined parameters. 

The 0-to-60 analysis presented above uses the method presented by MacKenzie for MY 1978-

2014. The authors believe that this new methodology is more accurate than the method 

historically used in this report, particularly for newer vehicles. MacKenzie’s methodology also 

better differentiates between different technologies, which is important given the wide range 

of new technologies entering the market that affect both 0-to-60 times and fuel economy. The 

methodology is applied beginning in 1978, since prior to that there is not enough data to 

apply the methodology. Additionally, MacKenzie’s method requires an annual factor that 

changes over time. The authors of this report assumed a constant annual factor for MY 2011 

to MY 2014, which is consistent with the last several years of data examined by MacKenzie. 

Changing methodologies for the 0-to-60 time calculation affects the results. For comparison, 

Figure 3.12 shows the overall trend in 0-to-60 acceleration times for new vehicles through MY 

2014 using both calculation methodologies. The MacKenzie methodology suggests that overall, 

new vehicle 0-to-60 acceleration is almost a full second faster than projected by the Malliaris 

methodology for MY 1990-2014. Both of the methodologies show a downward trend in 0-to60 acceleration times since at least MY 1982, however there are some clear differences between 

the two methods over time. The newer methodology shows a much faster reduction in 0-to-60 

times from MY 1982 until about MY 1993 (in part due to a higher 0-to-60 times in the early 

1980s). Since then, the rate of decrease in 0-to-60 times has been much more consistent 

between the two methods. 

Figure 3.12 

Comparison of Two Methods for Calculated 0-to-60 Acceleration Performance 

17.5 

15.0 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Seconds 

Malliaris Method 12.5 MacKenzie Method 

10.0 

7.5 

Model Year 

35 
 

 

 

 

Table 3.4 provides the calculated 0-to-60 times for both methodologies, and the differences in 

values based on the two methods. For more information on each methodology, please see the 

cited references. 

Table 3.4
 

Comparison Between 0-to-60 Acceleration Time Calculation Methods by Model Year (seconds)
 

Model 

Year 

Car Truck All Vehicles 

Malliaris 

Method 

MacKenzie 

Method 

Malliaris 

Method 

MacKenzie 

Method 

Malliaris 

Method 

MacKenzie 

Method 

Difference 

Between 

Methods 

% Difference 

Between 

Methods 

1975 14.2 - 13.6 - 14.1 - - -

1976 14.4 - 13.8 - 14.3 - - -

1977 14.0 - 13.3 - 13.8 - - -

1978 13.7 13.7 13.4 13.4 13.6 13.6 - -

1979 13.8 14.5 14.3 15.0 13.9 14.6 +0.7 +5.1% 

1980 14.3 15.5 14.5 15.7 14.3 15.6 +1.2 +8.6% 

1981 14.4 15.6 14.6 15.7 14.4 15.6 +1.2 +8.2% 

1982 14.4 16.6 14.5 16.6 14.4 16.6 +2.2 +15.6% 

1983 14.0 14.8 14.6 15.3 14.1 14.9 +0.8 +5.7% 

1984 13.8 14.5 14.7 15.3 14.0 14.7 +0.7 +5.3% 

1985 13.3 13.9 14.1 14.7 13.5 14.1 +0.6 +4.5% 

1986 13.2 13.2 14.0 13.9 13.4 13.4 0.0 +0.3% 

1987 13.0 13.3 13.4 13.6 13.1 13.4 +0.3 +2.2% 

1988 12.8 13.3 13.0 13.3 12.8 13.3 +0.5 +3.6% 

1989 12.4 12.5 12.8 12.7 12.5 12.5 0.0 -0.2% 

1990 12.1 11.4 12.6 11.8 12.2 11.5 -0.8 -6.3% 

1991 11.9 11.3 12.5 11.8 12.1 11.4 -0.6 -5.1% 

1992 11.5 10.8 12.5 11.5 11.8 11.0 -0.9 -7.2% 

1993 11.5 10.1 12.2 10.6 11.8 10.3 -1.5 -12.9% 

1994 11.4 9.9 12.0 10.4 11.7 10.1 -1.6 -13.5% 

1995 10.9 9.8 12.0 10.6 11.3 10.1 -1.2 -10.6% 

1996 10.8 10.1 11.6 10.7 11.1 10.4 -0.7 -6.7% 

1997 10.7 10.0 11.4 10.5 11.0 10.2 -0.8 -6.9% 

1998 10.6 10.2 11.2 10.7 10.9 10.4 -0.4 -4.1% 

1999 10.5 10.1 11.0 10.5 10.7 10.3 -0.5 -4.3% 

2000 10.4 9.5 11.0 10.1 10.6 9.8 -0.9 -8.2% 

2001 10.3 9.4 10.6 9.6 10.5 9.5 -1.0 -9.5% 

2002 10.2 9.4 10.3 9.5 10.2 9.4 -0.8 -8.0% 

2003 10.0 9.1 10.4 9.4 10.2 9.3 -0.9 -9.0% 

2004 9.8 9.0 10.1 9.2 9.9 9.1 -0.9 -8.8% 

2005 9.9 9.0 10.0 9.1 9.9 9.0 -0.9 -9.1% 

2006 9.6 8.8 10.0 9.1 9.8 8.9 -0.8 -8.7% 

2007 9.6 8.9 9.8 9.0 9.7 8.9 -0.8 -8.0% 

2008 9.6 8.9 9.7 9.0 9.7 8.9 -0.7 -7.5% 

2009 9.8 8.9 9.7 8.7 9.7 8.8 -0.9 -9.6% 

2010 9.6 8.8 9.7 8.8 9.6 8.8 -0.8 -8.7% 

2011 9.5 8.6 9.2 8.4 9.4 8.5 -0.9 -9.3% 

2012 9.5 8.6 9.1 8.3 9.4 8.5 -0.9 -9.3% 

2013 9.4 8.5 9.2 8.3 9.3 8.4 -1.0 -10.3% 

2014 9.5 8.3 9.2 8.1 9.4 8.2 -1.1 -12.0% 

* The value for the actual difference between methods for 1986 is 0.04, and for 1989 it is -0.03, which round to 0.0. 

36 
 

 

 

 

 

 

 

 

 

Manufacturers and Makes 

This section groups vehicles by “manufacturer” and “make.” Manufacturer definitions are those used by both 

EPA and the National Highway Traffic Safety Administration (NHTSA) for purposes of implementation of GHG 

emissions standards and the corporate average fuel economy (CAFE) program, respectively. Each year, the 

authors ensure that the manufacturer definitions in the Trends database are consistent with those used for 

regulatory compliance. 

Most of the tables in this section show, for new gasoline and diesel vehicles, adjusted CO2 emissions and fuel 

economy data which are the best estimates for real world CO2 emissions and fuel economy performance, but are 

not comparable to regulatory compliance values. Two tables in this section show unadjusted, laboratory fuel 

economy and CO2 emissions values, which form the basis for regulatory compliance values, though they do not 

reflect various compliance credits, incentives, and flexibilities available to automakers. Adjusted CO2 values are, 

on average, about 25% higher than the unadjusted CO2 values that form the starting point for GHG standards 

compliance. Adjusted fuel economy values are about 20% lower, on average, than unadjusted fuel economy 

values (note that these values differ because CO2 emissions are proportional to fuel consumption, both expressed 

in units of “per mile,” while fuel economy is the mathematical inverse of fuel consumption) that form the starting 

point for CAFE compliance. Section 7 contains additional data for alternative fuel vehicles that are not included in 

the gasoline/diesel values in this section. 

Information about compliance with EPA’s GHG emissions standards, including EPA’s Manufacturer Performance 

Report for the 2012 Model Year, is available at epa.gov/otaq/regs/ ld-hwy/greenhouse/ld-ghg.htm. NHTSA’s 

“Summary of Fuel Economy Performance,” summarizing automaker compliance with fuel economy standards, is 

available at nhtsa.dot.gov/fuel-economy. 

A. MANUFACTURER AND MAKE DEFINITIONS 

Table 4.1 lists the 13 manufacturers which had production of 100,000 or more gasoline or 

diesel vehicles in MY 2012 or MY 2013, which together accounted for approximately 98% of 

total industry-wide production. There are no changes in the list of manufacturers in Table 4.1 

included in this year’s report. Make is typically included in the model name and is generally 

equivalent to the “brand” of the vehicle. Table 4.1 also lists the 29 makes for which data are 

shown in subsequent tables. The production threshold for makes to be included in Tables 4.2 

through 4.5 is 40,000 vehicles in MY 2013, though some makes below this threshold are 

included if they are of particular interest. One change in this report is that Porsche is now 

included as a make under Volkswagen. 

37 
 

 

 

 

 

 

 

 

 

 

 

Table 4.1 

Manufacturers and Makes for MY 2012 - 2014 

Manufacturer Makes Above Threshold Makes Below Threshold 

General Motors Chevrolet, Cadillac, Buick, GMC 

Toyota Toyota, Lexus, Scion 

Ford Ford, Lincoln Roush, Shelby 

Honda Honda, Acura 

Chrysler-Fiat Chrysler, Dodge, Jeep, Ram, Fiat Ferrari, Maserati 

Nissan Nissan, Infiniti 

Hyundai Hyundai 

Kia Kia 

BMW BMW, Mini Rolls Royce 

Volkswagen Volkswagen, Audi, Porsche Lamborghini, Bentley, Bugatti 

Subaru Subaru 

Daimler Mercedes-Benz, Smart Maybach 

Mazda Mazda 

Others* 

*Note: Other manufacturers below the manufacturer threshold are Mitsubishi, Volvo, Rover,
 

Suzuki, Jaguar, Spyker (Saab), Aston Martin, Lotus, VPG, and Tesla (which only produces EVs).
 

It is important to note that when a manufacturer or make grouping is modified to reflect a 

change in the industry's current financial structure, EPA makes the same adjustment to the 

entire historical database. This maintains consistent manufacturer and make definitions over 

time, which allows a better identification of long-term trends. On the other hand, this means 

that the current database does not necessarily reflect the actual corporate arrangements of the 

past. For example, the 2014 database no longer accounts for the fact that Chrysler was 

combined with Daimler for several years, and includes Fiat, Ferrari, and Maserati in the 

Chrysler-Fiat manufacturer grouping for the entire database even though these other 

companies have been financially connected to Chrysler only recently. 

Automakers submit vehicle production data, rather than vehicle sales data, in formal end-ofyear CAFE and GHG emissions compliance reports to EPA. These vehicle production data 

are tabulated on a model year basis. Accordingly, the vehicle production data presented in 

this report often differ from similar data reported by press sources, which typically are based 

on vehicle sales data reported on a calendar basis. In years past, manufacturers typically used a 

more consistent approach for model year designations, i.e., from fall of one year to the fall of 

the following year. More recently, however, many manufacturers have used a more flexible 

approach, and it is not uncommon to see a new or redesigned model introduced with a new 

model year designation in the spring or summer, rather than the fall. This means that a model 

year for an individual vehicle can be either shortened or lengthened. Accordingly, year-to-year 

comparisons can be affected by these model year anomalies, though the overall trends even out 

over a multi-year period. 

38 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B. MANUFACTURER AND MAKE FUEL ECONOMY 

AND CO2 EMISSIONS 

Tables 4.2 through 4.5 provide comparative manufacturer- and make-specific data for fuel 

economy and CO2 emissions for the three years from MY 2012-2014. Data are shown for cars 

only, trucks only, and cars and trucks combined. By including data from both MY 2012 and 

2013, with formal end-of-year data for both years, it is possible to identify meaningful changes 

from year-to-year. Because of the uncertainty associated with the preliminary MY 2014 

projections, changes from MY 2013 to MY 2014 are less meaningful. 

In this section, tables are presented with both adjusted (Tables 4.2 and 4.3) and unadjusted, 

laboratory (Tables 4.4 and 4.5) data. Tables 4.2 and 4.3 provide adjusted data for fuel 

economy and CO2 emissions, and therefore are consistent with tables presented earlier in the 

report. The data in these tables are very similar to the data used to generate the EPA/DOT 

Fuel Economy and Environment Labels and represent EPA’s best estimate of nationwide real 

world fuel consumption and CO2 emissions. 

It is important to note that Tables 4.2 and 4.3 show rows with adjusted fuel economy and CO2 

emissions data for 11 manufacturers and 27 makes, while the table footnotes provide similar 

data for two additional manufacturers, Hyundai and Kia. On November 2, 2012, EPA 

announced that Hyundai and Kia would lower their Fuel Economy and Environment Label 

estimates for many vehicle models as the result of an EPA investigation of test data. Hyundai 

and Kia submitted corrected MY 2011 - 2013 fuel economy and CO2 emissions data to EPA 

and re-labeled many of their model year 2012 and 2013 vehicles on the market. This report 

uses the corrected fuel economy values submitted by Hyundai and Kia for four MY 2011 

vehicles and for many Hyundai and Kia vehicles for MY 2012 and 2013. The magnitude of 

the changes between the original label values and the corrected label values ranges from 1 mpg 

to 6 mpg. For the changes in the label values for individual vehicles, see 

epa.gov/fueleconomy/labelchange.htm. Since EPA’s investigation into Hyundai and Kia data 

submissions is continuing, Hyundai and Kia-specific values are not shown in rows in the 

following tables that list the fuel economy and CO2 emissions performance for various 

manufacturers, but are provided in footnotes to the tables with adjusted fuel economy and 

CO2 emissions. Hyundai and Kia data are included in industry-wide values, including the 

“All” rows in the following tables, throughout this report. 

It is also important to note that the data in the following tables reflect underlying data that are 

consistent with the revised fuel economy label values that were adopted in 2013 for the Ford 

C-Max hybrid, and in 2014 for several Ford vehicles. 

Of the 11 manufacturers shown in the body of Table 4.2, 9 manufacturers increased adjusted 

fuel economy from MY 2012 to MY 2013, and Mazda had the highest adjusted fuel economy 

in MY 2013 of 28.1 mpg. Honda had the second highest adjusted fuel economy of 27.4 mpg, 

39 
 

 

 

 

followed by Subaru at 26.7 mpg. Chrysler-Fiat had the lowest adjusted fuel economy of 20.9 

mpg, followed by General Motors and Ford. Nissan achieved the largest increase in adjusted 

fuel economy from MY 2012-2013 of 2.1 mpg, followed by Subaru at 1.5 mpg and Daimler at 

1.3 mpg. The two manufacturers with lower adjusted fuel economy values in MY 2013 are 

Ford and Toyota. Ford’s overall MY 2013 decline of 0.6 mpg is explained by a 12% increase in 

truck share, as the fuel economies for its individual car and truck fleets both increased in MY 

2012. Toyota’s 0.5 mpg fleetwide decrease in MY 2013 is partially explained by its increased 

truck share of 5%, but while its truck fleet fuel economy increased, its car fleet fuel economy 

decreased by 0.4 mpg. 

For MY 2013 cars only, Honda, Toyota, and Mazda had the highest adjusted fuel economy 

values of 30.2 and 30.3 mpg, while Daimler reported the lowest adjusted car fuel economy of 

24.1 mpg. For MY 2013 trucks only, Subaru had the highest adjusted fuel economy of 26.0 

mpg, while General Motors had the lowest at 18.1 mpg. 

40 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4.2 

Adjusted Fuel Economy (MPG) by Manufacturer and Make for MY 2012 - 2014* 

Manufacturer Make 

Final MY 2012 Final MY 2013 Preliminary MY 2014 

Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks 

Mazda 

Honda 

Honda 

Honda 

Subaru 

Nissan 

Nissan 

Nissan 

VW 

VW 

VW 

VW 

Toyota 

Toyota 

Toyota 

Toyota 

BMW 

BMW 

BMW 

Daimler 

Daimler 

Daimler 

Ford 

Ford 

Ford 

GM 

GM 

GM 

GM 

GM 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Other 

All 

Honda 

Acura 

All 

All 

Nissan 

Infiniti 

All 

VW 

Audi 

Porsche 

All 

Toyota 

Lexus 

Scion 

All 

BMW 

Mini 

All 

Mercedes-Benz 

Smart 

All 

Ford 

Lincoln 

All 

Chevrolet 

GMC 

Buick 

Cadillac 

All 

Dodge 

Chrysler 

Jeep 

Ram 

Fiat 

All 

All 

29.3 

29.9 

24.5 

29.3 

27.5 

27.5 

21.9 

26.9 

27.2 

24.0 

22.0 

26.2 

31.8 

24.8 

27.2 

30.7 

23.3 

29.9 

25.3 

22.4 

35.7 

22.6 

27.2 

22.6 

26.9 

25.7 

23.7 

24.0 

20.5 

24.8 

22.7 

23.8 

22.2 

-

31.5 

23.7 

24.2 

21.9 27.1 

22.8 27.2 

18.4 21.8 

22.2 26.6 

24.0 25.2 

18.9 24.5 

17.0 20.5 

18.8 24.1 

22.8 26.9 

21.5 23.1 

19.5 20.8 

21.5 25.5 

19.7 25.7 

20.7 23.5 

- 27.2 

19.7 25.6 

20.1 22.0 

- 29.9 

20.1 23.7 

18.4 20.9 

- 35.7 

18.4 21.1 

18.5 22.9 

17.6 20.9 

18.5 22.8 

18.0 22.4 

18.0 19.3 

19.6 22.1 

15.5 19.6 

18.1 21.7 

20.2 21.4 

20.9 22.6 

18.7 19.2 

16.1 16.1 

- 31.5 

18.6 20.1 

18.4 21.7 

30.2 

30.8 

25.8 

30.3 

27.9 

30.2 

21.7 

29.2 

27.5 

23.8 

23.0 

26.4 

32.0 

25.3 

27.0 

30.3 

25.0 

30.2 

26.0 

23.5 

36.5 

24.1 

27.3 

23.5 

27.1 

26.5 

24.3 

24.8 

21.5 

25.5 

24.4 

23.5 

24.8 

-

31.7 

24.5 

24.4 

23.8 28.1 

23.0 27.9 

20.4 23.5 

22.7 27.4 

26.0 26.7 

21.1 27.0 

20.1 21.0 

21.0 26.2 

22.5 27.2 

21.7 23.2 

20.1 21.6 

21.6 25.7 

20.1 25.4 

20.4 23.6 

- 27.0 

20.2 25.1 

20.7 23.5 

- 30.2 

20.7 24.5 

19.3 22.0 

- 36.5 

19.3 22.4 

19.1 22.3 

18.2 21.2 

19.0 22.2 

18.2 22.6 

18.0 19.3 

20.5 23.6 

15.4 20.5 

18.1 22.0 

20.2 22.4 

20.6 22.3 

18.6 19.1 

16.6 16.6 

- 31.7 

18.8 20.9 

19.2 21.6 

31.9 24.2 28.8 

31.3 23.0 28.1 

25.9 22.7 24.8 

30.4 22.9 27.6 

28.6 26.9 27.5 

30.6 21.0 27.4 

23.3 21.0 22.3 

29.8 21.0 26.8 

29.2 22.5 28.7 

24.0 22.1 23.4 

22.7 20.1 21.8 

27.6 21.9 26.7 

33.1 19.8 26.1 

25.1 20.1 23.5 

28.2 - 28.2 

31.4 19.8 25.8 

26.1 22.9 25.4 

30.6 - 30.6 

26.7 22.9 26.0 

24.7 19.6 22.8 

36.5 - 36.5 

24.8 19.6 22.8 

28.1 19.3 23.4 

26.9 19.6 23.2 

28.0 19.3 23.4 

26.6 18.9 22.8 

23.3 18.5 19.2 

25.1 21.1 23.4 

22.1 15.4 21.0 

25.5 18.8 22.0 

23.5 20.4 22.1 

23.2 20.9 22.1 

24.8 20.4 21.4 

- 17.5 17.5 

29.3 - 29.3 

24.0 19.7 21.1 

24.9 20.6 22.4 

All All 27.0 19.3 23.6 27.6 19.8 24.1 27.9 20.1 24.2 

*Note: Hyundai and Kia are not included in this table due to a continuing investigation. In November 2012, 

Hyundai and Kia corrected fuel economy labels for many vehicle models. Based on these corrected data, 

Hyundai’s values are 28.3 mpg for MY 2012, 29.0 mpg for MY 2013, and 27.3 mpg for MY 2014. Kia’s values 

are 26.5 mpg for MY 2012, 27.4 mpg for MY 2013, and 25.7 mpg for MY 2014. Hyundai and Kia adopted 

unusually short MY 2014 production time frames for some high fuel economy models, which the authors 

believe is the primary reason for their lower preliminary MY 2014 values. The corrected Hyundai and Kia 

data are included in industry-wide or “All” values. 

41 
 

 

 

 

 

 

 

 

 

 

 

 

In terms of the makes shown in Table 4.2 for MY 2013, the Smart make had the highest 

adjusted fuel economy at 36.5 mpg. The Smart Fourtwo is the smallest and lightest car in the 

U.S. market and has relatively low production. Other makes with high fuel economy include 

Fiat at 31.7 mpg and Mini at 30.2 mpg. 

Preliminary projections suggest that 10 of the 11 manufacturers shown will improve adjusted 

fuel economy further in MY 2014, though EPA will not have final data for MY 2014 until 

next year’s report. The preliminary MY 2014 value for GM would represent no change relative 

to MY 2013. Hyundai and Kia adopted unusually short MY 2014 production time frames for 

some of their highest fuel economy vehicles, and the authors believe this is the primary reason 

for the lower preliminary MY 2014 values for Hyundai and Kia as shown in the footnote. 

Table 4.3 shows manufacturer-specific values for adjusted CO2 emissions for the same 

manufacturers, makes and model years as shown in Table 4.2 for adjusted fuel economy. Of 

the 11 manufacturers shown, 9 manufacturers decreased adjusted CO2 emissions from MY 

2012 to MY 2013. Manufacturer rankings for CO2 emissions are generally similar to those for 

fuel economy, though there can be some differences due to diesel vehicle production share 

(since diesel has a higher carbon content per gallon than gasoline). Of the 11 manufacturers 

shown in Table 4.3, Mazda had the lowest adjusted CO2 emissions in MY 2013 of 316 g/mi, 

followed by Honda at 324 g/mi and Subaru at 332 g/mi. Chrysler-Fiat had the highest 

adjusted CO2 emissions of 425 g/mi, followed by General Motors and Ford. Nissan achieved 

the largest decrease in adjusted CO2 emissions from MY 2012-2013 of 30 g/mi, followed by 

Daimler at 27 g/mi and Subaru at 20 g/mi. Preliminary values suggest that 10 of the 11 

manufacturers will likely reduce CO2 emissions in MY 2014, with GM constant. The make 

rankings for adjusted CO2 emissions in Table 4.3 are also similar to those for adjusted fuel 

economy in Table 4.2. 

42 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4.3 

Adjusted CO2 Emissions (g/mi) by Manufacturer and Make for MY 2012 - 2014* 

Manufacturer Make 

Final MY 2012 Final MY 2013 Preliminary MY 2014 

Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks 

Mazda 

Honda 

Honda 

Honda 

Subaru 

Nissan 

Nissan 

Nissan 

VW 

VW 

VW 

VW 

Toyota 

Toyota 

Toyota 

Toyota 

BMW 

BMW 

BMW 

Daimler 

Daimler 

Daimler 

Ford 

Ford 

Ford 

GM 

GM 

GM 

GM 

GM 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Other 

All 

Honda 

Acura 

All 

All 

Nissan 

Infiniti 

All 

VW 

Audi 

Porsche 

All 

Toyota 

Lexus 

Scion 

All 

BMW 

Mini 

All 

Mercedes-Benz 

Smart 

All 

Ford 

Lincoln 

All 

Chevrolet 

GMC 

Buick 

Cadillac 

All 

Dodge 

Chrysler 

Jeep 

Ram 

Fiat 

All 

All 

304 

298 

362 

303 

323 

323 

406 

330 

334 

372 

405 

345 

280 

358 

326 

290 

382 

297 

352 

398 

249 

394 

327 

393 

330 

346 

375 

371 

434 

358 

392 

373 

401 

-

282 

376 

368 

406 328 

390 327 

482 407 

400 334 

371 352 

470 363 

524 434 

474 369 

405 338 

419 388 

455 427 

421 355 

452 345 

429 378 

- 326 

450 347 

452 407 

- 297 

452 377 

495 430 

- 249 

495 426 

479 389 

505 425 

480 390 

494 396 

493 461 

454 401 

574 453 

492 410 

439 416 

425 393 

474 463 

553 553 

- 282 

478 442 

484 410 

294 

289 

344 

294 

319 

294 

409 

304 

332 

373 

386 

343 

278 

352 

329 

294 

356 

295 

342 

378 

244 

370 

324 

375 

327 

336 

366 

359 

413 

349 

364 

378 

359 

-

281 

363 

364 

374 316 

386 319 

436 378 

391 324 

342 332 

421 329 

441 424 

424 339 

404 336 

414 385 

455 419 

420 353 

442 350 

435 377 

- 329 

441 354 

430 378 

- 295 

430 363 

469 407 

- 244 

469 399 

466 399 

488 418 

467 400 

489 393 

494 460 

433 377 

577 434 

490 404 

441 396 

432 398 

477 466 

535 535 

- 281 

473 425 

463 411 

279 368 309 

284 387 317 

344 392 358 

292 388 322 

310 330 324 

290 422 324 

381 423 398 

298 422 332 

314 403 319 

372 415 385 

391 453 412 

329 418 340 

268 450 340 

354 443 377 

315 - 315 

283 449 344 

343 393 353 

291 - 291 

335 393 344 

361 463 394 

244 - 244 

360 463 393 

316 460 379 

330 453 384 

317 460 380 

335 470 391 

382 480 464 

354 421 380 

403 578 423 

348 472 404 

378 436 402 

384 425 402 

359 435 415 

- 508 508 

304 - 304 

370 451 420 

357 432 397 

All All 329 461 376 322 450 369 320 442 367 

*Note: Hyundai and Kia are not included in this table due to a continuing investigation. In November 2012, 

Hyundai and Kia corrected fuel economy labels for many vehicle models. Based on these corrected data, 

Hyundai’s CO2 emissions values are 314 g/mi for MY 2012, 306 g/mi for MY 2013, and 326 g/mi for MY 2014. 

Kia’s CO2 values are 336 g/mi for MY 2012, 324 g/mi for MY 2013, and 345 g/mi for MY 2014. Hyundai and 

Kia adopted unusually short MY 2014 production time frames for some high fuel economy models, which the 

authors believe is the primary reason for their higher preliminary MY 2014 CO2 emissions values. The 

corrected Hyundai and Kia data are included in industry-wide or “All” values. 

43 
 

 

 

 

 

 

Tables 4.4 and 4.5 provide unadjusted, laboratory data for both fuel economy and CO2 

emissions for MY 2012-2014 on a manufacturer-specific basis. Unadjusted, laboratory data is 

relevant in a manufacturer-specific context because it is the foundation for EPA CO2 

emissions and NHTSA CAFE regulatory compliance, and because it provides a basis for 

comparing long-term trends from the perspective of vehicle design only, apart from the factors 

that affect real world performance that can change over time (i.e., driving behavior such as 

acceleration rates or the use of air conditioning). Note that EPA has not released corrected 

unadjusted, laboratory values for some Hyundai and Kia models for MY 2011-2013. 

In general, manufacturer rankings based on the unadjusted, laboratory values in Tables 4.4 

and 4.5 are very similar to those for the adjusted values in Tables 4.2 and 4.3. On average, in 

recent years, unadjusted, laboratory fuel economy values are about 25% greater than adjusted 

fuel economy values (slightly greater at higher mpg levels), and average unadjusted, laboratory 

CO2 emissions values are about 20% less than adjusted CO2 emissions (slightly greater at 

lower CO2 emissions levels). 

44 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4.4 

Unadjusted, Laboratory Fuel Economy (MPG) by Manufacturer and Make for MY 2012 - 2014* 

Manufacturer Make 

Final 2012 Final 2013 Preliminary 2014 

Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks Cars Trucks 

Cars 

and 

Trucks 

Mazda 

Honda 

Honda 

Honda 

Subaru 

Nissan 

Nissan 

Nissan 

VW 

VW 

VW 

VW 

Toyota 

Toyota 

Toyota 

Toyota 

BMW 

BMW 

BMW 

Daimler 

Daimler 

Daimler 

Ford 

Ford 

Ford 

GM 

GM 

GM 

GM 

GM 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Chrysler-Fiat 

Other 

All 

Honda 

Acura 

All 

All 

Nissan 

Infiniti 

All 

VW 

Audi 

Porsche 

All 

Toyota 

Lexus 

Scion 

All 

BMW 

Mini 

All 

Mercedes-Benz 

Smart 

All 

Ford 

Lincoln 

All 

Chevrolet 

GMC 

Buick 

Cadillac 

All 

Dodge 

Chrysler 

Jeep 

Ram 

Fiat 

All 

All 

37.4 

38.1 

30.9 

37.3 

35.2 

35.3 

27.4 

34.4 

34.2 

29.5 

27.3 

32.8 

41.4 

31.5 

35.2 

39.8 

29.4 

38.7 

32.2 

27.8 

49.5 

28.2 

34.5 

28.4 

34.1 

32.2 

29.8 

29.7 

25.4 

31.1 

28.1 

29.5 

28.2 

-

41.1 

29.6 

30.4 

27.8 34.6 

28.6 34.5 

23.3 27.5 

27.8 33.6 

30.5 32.2 

23.7 31.1 

20.9 25.5 

23.5 30.5 

28.9 33.9 

26.7 28.5 

24.6 26.1 

26.9 31.9 

24.8 33.0 

26.1 29.8 

- 35.2 

24.9 32.8 

25.0 27.7 

- 38.7 

25.0 30.0 

23.1 26.1 

- 49.5 

23.1 26.3 

23.2 28.8 

21.9 26.1 

23.1 28.7 

22.3 28.0 

22.4 24.1 

24.5 27.5 

20.1 24.6 

22.4 27.0 

25.1 26.5 

25.9 28.0 

23.5 24.1 

19.8 19.8 

- 41.1 

23.1 25.0 

22.9 27.2 

38.9 

39.7 

32.5 

39.0 

35.7 

39.2 

27.2 

37.8 

34.7 

29.6 

28.8 

33.2 

41.8 

32.2 

34.6 

39.3 

31.4 

39.0 

32.9 

29.4 

50.3 

30.2 

34.8 

29.7 

34.5 

33.4 

31.0 

30.9 

26.7 

32.1 

30.5 

29.2 

31.8 

-

41.3 

30.6 

30.8 

30.4 36.1 

28.9 35.6 

25.6 29.6 

28.5 34.9 

33.3 34.2 

26.8 34.7 

25.3 26.3 

26.5 33.6 

28.5 34.3 

27.2 28.9 

25.2 27.0 

27.1 32.2 

25.4 32.5 

25.7 29.9 

- 34.6 

25.4 32.2 

25.8 29.4 

- 39.0 

25.8 30.8 

24.4 27.6 

- 50.3 

24.4 28.2 

23.8 28.0 

22.7 26.6 

23.8 27.9 

22.5 28.3 

22.4 24.2 

25.8 29.4 

19.9 25.6 

22.6 27.5 

25.0 28.0 

25.4 27.7 

23.4 24.0 

20.5 20.5 

- 41.3 

23.4 26.0 

23.9 27.1 

41.2 30.9 37.0 

40.4 28.8 35.8 

32.6 28.4 31.2 

39.1 28.8 35.1 

36.7 34.5 35.3 

39.7 26.6 35.2 

29.3 26.5 28.1 

38.5 26.6 34.3 

36.6 28.5 36.0 

29.8 27.6 29.1 

28.4 25.2 27.2 

34.5 27.4 33.4 

43.4 25.0 33.6 

32.0 25.2 29.9 

36.6 - 36.6 

40.9 25.0 33.1 

32.6 28.9 31.9 

39.7 - 39.7 

33.6 28.9 32.7 

31.0 24.8 28.7 

50.3 - 50.3 

31.1 24.8 28.8 

35.7 24.1 29.5 

34.4 24.5 29.3 

35.6 24.2 29.5 

33.6 23.5 28.5 

29.8 23.1 24.0 

31.9 26.6 29.7 

27.4 20.1 26.3 

32.2 23.5 27.6 

29.2 25.2 27.4 

28.6 25.9 27.3 

31.5 25.6 27.0 

- 21.6 21.6 

37.6 - 37.6 

30.1 24.6 26.4 

31.4 25.5 27.9 

All All 34.3 24.1 29.8 35.2 24.8 30.5 35.5 25.2 30.6 

*Note: Hyundai and Kia are not included in rows in the table above due to a continuing investigation. 

On November 2, 2012, EPA announced that Hyundai and Kia would lower their fuel economy estimates 

for many vehicle models as the result of an EPA investigation of test data. EPA has not yet released 

formal, corrected unadjusted, laboratory fuel economy values for Hyundai and Kia. 

45 
46 

Table 4.5 

Unadjusted, Laboratory CO2 Emissions (g/mi) by Manufacturer and Make for MY 2012 - 2014* 

 Final MY 2012 Final MY 2013 Preliminary MY 2014

Manufacturer Make Cars Trucks

Cars

and 

Trucks Cars Trucks

Cars

and 

Trucks Cars Trucks

Cars 

and 

Trucks

Mazda All 238 319 257 229 293 246 216 288 240

Honda Honda 233 311 258 224 307 250 220 308 248

Honda Acura 288 382 323 273 347 300 273 313 285

Honda All 238 319 264 228 312 254 227 309 253

Subaru All 252 292 276 249 267 259 242 257 252

Nissan Nissan 252 375 286 227 332 256 224 334 252

Nissan Infiniti 325 425 348 327 352 338 303 335 316

Nissan All 258 378 291 235 335 265 231 334 259

Toyota Toyota 215 358 269 213 350 273 205 356 265

Toyota Lexus 282 340 299 276 346 297 278 353 298

Toyota Scion 252 - 252 257 - 257 243 - 243

Toyota All 223 357 271 226 349 276 217 356 268

VW VW 266 319 268 263 319 266 250 319 254

VW Audi 303 337 314 301 331 309 301 333 310

VW Porsche 325 362 341 309 363 335 313 362 330

VW All 276 336 283 273 334 281 263 333 272

BMW BMW 303 363 324 283 345 302 274 312 281

BMW Mini 230 - 230 228 - 228 224 - 224

BMW All 276 363 299 270 345 289 266 312 273

Daimler Mercedes-Benz 320 394 344 302 370 324 288 366 313

Daimler Smart 180 - 180 177 - 177 177 - 177

Daimler All 316 394 341 294 370 317 286 366 312

Ford Ford 258 384 309 255 374 317 249 368 301

Ford Lincoln 313 406 340 299 391 334 258 362 304

Ford All 261 384 310 257 374 318 250 368 302

GM Chevrolet 276 399 318 266 394 314 265 379 312

GM GMC 298 396 369 286 397 367 298 385 370

GM Buick 299 363 323 288 344 302 279 334 300

GM Cadillac 350 443 362 332 446 347 324 442 337

GM All 286 396 329 277 394 323 276 379 322

Chrysler-Fiat Dodge 316 354 335 292 355 318 304 352 325

Chrysler-Fiat Chrysler 301 343 318 305 349 321 311 343 325

Chrysler-Fiat Jeep 315 379 369 279 379 370 282 347 329

Chrysler-Fiat Ram - 448 448 - 433 433 - 411 411

Chrysler-Fiat Fiat 216 - 216 215 - 215 236 - 236

Chrysler-Fiat All 301 384 355 290 380 341 296 362 337

Other All 292 389 327 289 372 329 283 349 318

All All 259 369 298 253 359 292 251 353 290

*Note: Hyundai and Kia are not included in rows in the table above due to a continuing investigation. On 

November 2, 2012, EPA announced that Hyundai and Kia would lower their fuel economy estimates for 

many vehicle models as the result of an EPA investigation of test data. EPA has not yet released formal, 

corrected unadjusted, laboratory CO2 emissions values for Hyundai and Kia.
 

 

C. MANUFACTURER TECHNOLOGY AND ATTRIBUTE 

TRENDS 

Figure 4.1 shows the “top three” of the 13 largest manufacturers, in terms of the percent of 

each manufacturer’s projected MY 2014 production that uses various technologies discussed 

in more detail in Section 5, as well as the projected industry-wide average technology 

production share for MY 2014. 

Figure 4.1 

Highest Technology Adoption Based on Projected MY 2014 Production 

0% 

25% 

50% 

75% 

100% 

GDI Turbo 

BMW Daimler Kia All BMW VW Daimler All 

Cylinder Deactivation Non-Hybrid Stop/Start 

GM Honda Chrysler− All BMW Daimler VW All 

Fiat 

CVT 7 or More Gears 

100% 

75% 

50% 

25% 

0% 

Subaru Nissan Honda All Daimler BMW Chrysler− All 

Fiat 

0% 

25% 

50% 

75% 

100% 

Percent of 2014 Manufacturer Projected Production 

0% 

25% 

50% 

75% 

100% 

Hybrid Diesel 

Toyota Honda Ford All VW Daimler BMW All 

47 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

In terms of individual technologies, BMW has the highest projected production share for 

turbocharging (96%) and non-hybrid stop/start (75%), Daimler for transmissions with 7 or 

more gears (99%), Toyota for hybrids (15%), and Volkswagen for diesels (20%). BMW, 

Daimler, and Kia are projected to use gasoline direct injection engines in about 90% of their 

fleets, General Motors and Honda are projected to use cylinder deactivation in about 35% of 

their production, and Subaru and Nissan are projected to use continuously variable 

transmissions in about 85% of their fleets. 

In terms of the “top three” for these eight technologies in Figure 4.1, BMW and Daimler are 

represented five times each, and Honda and Volkswagen are represented three times each. Of 

the 13 largest manufacturers, 11 are represented in the “top three” for at least one of the eight 

technologies. The two manufacturers not represented in any of the “top three” in Figure 4.1 

are Hyundai and Mazda, both of which have low truck production shares, low average 

footprint, low average weight, and low horsepower values relative to most other manufacturers. 

Table 4.6 shows footprint by manufacturer for MY 2012-2014. In recent years, industry-wide 

footprint has been fluctuating around 49 square feet. GM, Ford, and Chrysler-Fiat had the 

largest footprint values in MY 2011 in the 51.5 to 53.5 square feet range, and Subaru and 

Mazda had the lowest footprint values of 44 to 45 square feet. The remaining manufacturers 

had average footprint values in the 46 to 48 square feet range. 

Table 4.6 

Footprint (square feet) by Manufacturer for MY 2012 - 2014 

Manufacturer 

MY 2012 MY 2013 MY 2014 

Cars Trucks 

Cars and 

Trucks Cars Trucks 

Cars and 

Trucks Cars Trucks 

Cars and 

Trucks 

Ford 45.3 59.4 50.9 47.0 59.5 53.5 46.2 58.4 51.6 

GM 47.0 60.1 52.1 46.5 60.4 52.0 46.4 61.1 52.9 

Toyota 45.1 53.4 48.1 45.1 52.5 48.1 45.0 53.7 48.2 

Chrysler-Fiat 47.2 53.6 51.4 47.6 54.5 51.5 47.2 50.8 49.4 

Honda 45.0 50.5 46.8 44.9 49.3 46.3 45.7 50.4 47.2 

Nissan 45.0 51.6 46.8 45.8 50.8 47.3 45.5 52.7 47.5 

Hyundai 46.4 46.4 46.4 46.1 46.8 46.2 45.9 46.5 46.0 

VW 45.0 49.5 45.6 45.2 49.6 45.8 45.3 48.9 45.8 

Kia 45.6 52.0 46.2 45.5 45.6 45.5 45.5 49.9 45.8 

BMW 45.9 51.4 47.3 46.2 50.8 47.4 46.8 50.7 47.4 

Subaru 44.3 44.7 44.5 44.0 44.6 44.4 44.1 44.6 44.4 

Daimler 46.5 51.8 48.2 45.5 51.5 47.3 47.6 51.6 48.9 

Mazda 43.9 48.1 44.9 43.6 47.6 44.7 44.9 47.5 45.8 

Other 45.6 47.9 46.5 45.9 47.8 46.8 45.9 48.2 47.1 

All 45.7 54.5 48.8 45.9 54.7 49.2 45.9 54.4 49.2 

Manufacturer-specific MY 2013 car footprint values varied little, within 44-48 square feet. MY 

2013 truck footprint values were much more variable, ranging from 45 (Subaru) to 60 (General 

Motors) square feet. 

48 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In terms of change in footprint values from MY 2012 to MY 2013, six manufacturers increased 

footprint, with Ford having the largest increase of 2.6 square feet. As with its MY 2013 fuel 

economy decrease, this is heavily influenced by its 12% increase in truck share, as its average 

truck footprint is 12.5 square feet greater than its average car footprint. Six manufacturers 

decreased footprint, with the biggest decreases reported by Daimler (0.9 square foot), Kia (0.7 

square foot) and Honda (0.5 square foot). Industry-wide footprint is projected to remain 

unchanged in MY 2014. 

Table 4.7 shows manufacturer-specific values for adjusted fuel economy and production share 

for the two classes (cars and trucks) and the five vehicle types (cars, car SUVs, truck SUVs, 

pickups, and minivans/vans) for 11 manufacturers for MY 2013. Toyota had the highest 

adjusted fuel economy for the car type, while Mazda led for car SUVs. For the truck types, 

Subaru reported the highest adjusted fuel economy for truck SUVs, Toyota and Nissan had the 

highest pickup fuel economy among manufacturers that make a significant number of pickups, 

and Mazda had the highest adjusted fuel economy for minivans/vans. Subaru had the highest 

truck share of 59%, followed by Chrysler-Fiat at 57%. 

Industry-wide, car type vehicles averaged 3.8 mpg higher than car SUVs in MY 2013, with this 

difference decreasing by 0.6 mpg since MY 2012. Among truck types, minivans/vans had the 

highest adjusted fuel economy of 21.1 mpg, followed by truck SUVs at 20.9 mpg, and pickups 

at 17.4 mpg. The biggest fuel economy increases since MY 2012 were from car SUVs at 1.1 mpg 

and truck SUVs at 0.9 mpg. 

Table 4.7
 

Adjusted Fuel Economy and Production Share by Vehicle Classification and Type for MY 2013*
 

Manufacturer 

Cars Car SUVs All Cars Truck SUVs Pickups Minivans/Vans All Trucks 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Adj FE 

(MPG) 

Prod 

Share 

Ford 28.4 34.1% 24.3 14.1% 27.1 48.2% 20.8 23.4% 17.5 26.5% 22.7 1.9% 19.0 51.8% 

GM 25.9 43.9% 24.4 16.7% 25.5 60.6% 19.0 21.1% 17.3 17.6% 16.1 0.7% 18.1 39.4% 

Toyota 31.3 52.1% 24.4 7.3% 30.3 59.3% 21.2 23.2% 18.0 11.7% 21.1 5.8% 20.2 40.7% 

Chrysler-Fiat 24.5 40.7% 23.6 2.8% 24.5 43.4% 19.0 26.9% 16.5 12.8% 20.6 16.9% 18.8 56.6% 

Honda 31.0 59.6% 26.0 8.8% 30.3 68.4% 23.1 24.3% 18.1 1.2% 22.4 6.1% 22.7 31.6% 

Nissan 30.1 61.8% 24.3 8.8% 29.2 70.5% 21.7 23.0% 17.9 5.1% 22.7 1.4% 21.0 29.5% 

VW 26.5 84.3% 23.6 2.6% 26.4 86.9% 21.6 13.1% - - - - 21.6 13.1% 

BMW 26.0 75.4% - - 26.0 75.4% 20.7 24.6% - - - - 20.7 24.6% 

Subaru 27.9 40.8% - - 27.9 40.8% 26.0 59.2% - - - - 26.0 59.2% 

Daimler 24.2 65.5% 22.1 4.4% 24.1 69.9% 19.3 30.1% - - - - 19.3 30.1% 

Mazda 30.3 60.1% 29.5 12.9% 30.2 73.0% 23.5 20.8% - - 24.8 6.3% 23.8 27.0% 

Other 24.2 39.3% 25.1 12.9% 24.4 52.2% 19.2 47.8% - - - - 19.2 47.8% 

All 28.3 53.5% 24.5 9.9% 27.6 63.2% 20.9 22.4% 17.4 10.6% 21.1 3.8% 19.8 36.8% 

*Hyundai and Kia are not included in this table due to a continuing investigation. 

Table 4.8 shows average MY 2013 manufacturer-specific values, for all cars and trucks, for 

three important vehicle attributes: footprint, weight, and horsepower. The footprint data in 

Table 4.8 were also shown in Table 4.6 and discussed above. Ford had the highest average 

49 
 

 

 

 

 

 

weight of 4492 pounds, followed by General Motors and Daimler. Mazda reported the lowest 

average weight of 3295 pounds, followed by Hyundai and Kia. Daimler also had the highest 

average horsepower level of 284 hp, followed by Chrysler-Fiat, BMW, and Ford. Mazda also 

reported the lowest horsepower level of 165 hp, followed by Subaru. 

Table 4.8 

Vehicle Footprint, Weight, and Horsepower by Manufacturer for MY 2013 

Footprint Weight 

Manufacturer (sq ft) (lb) HP 

Ford 53.5 4492 265 

GM 52.0 4404 250 

Toyota 48.1 3926 203 

Chrysler-Fiat 51.5 4328 268 

Honda 46.3 3606 192 

Nissan 47.3 3723 205 

Hyundai 46.2 3313 183 

VW 45.8 3779 204 

Kia 45.5 3363 184 

BMW 47.4 4012 267 

Subaru 44.4 3629 174 

Daimler 47.3 4352 284 

Mazda 44.7 3295 165 

All 49.2 4015 227 

Finally, Figure 4.2 provides a historical perspective, for both adjusted fuel economy and truck 

share, for each of the top 13 manufacturers. Adjusted fuel economy is presented for cars only, 

trucks only, and cars and trucks combined. One noteworthy result in Figure 4.2 is that there 

is very little difference between the adjusted fuel economy values for Subaru cars and trucks, 

the only manufacturer for which this is the case. 

More information for the historic Trends database stratified by manufacturer can be found in 

Appendices J and K. 

50 
 

 

Figure 4.2 

Adjusted Fuel Economy and Percent Truck by Manufacturer for MY 1975 - 2014 Percent Truck Adjusted MPG Percent Truck Adjusted MPG

0% 

20% 

40% 

60% 

80% 

Nissan Hyundai VW Kia BMW 

10 

15 

20 

25 

30 

Toyota Chrysler-Fiat Honda 

10 

15 

20 

25 

30 

0% 

20% 

40% 

60% 

80% 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both 

Truck 

Both 

Car 

Ford GM 

1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 

1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 

Subaru Daimler Mazda Other 

30 

Percent Truck Adjusted MPG 

25 

20 

15 

10 

80% 

60% 

40% 

20% 

0% 

1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 1980 1990 2010 2000 

Car 

Truck 

Both 

Car 

Truck 

Both 

Car 

Truck 

Both Car 

Truck 

Both 

51 
 

I 

 

 

 

 

 

 

 

 

 

 

 

Powertrain Technologies 

Technological innovation is a major driver of vehicle design in general, and vehicle fuel economy and CO2 

emissions in particular. Since its inception, this report has tracked the usage of key technologies as well as many 

major engine and transmission parameters. This section of the report will focus on the larger technology trends in 

engine and transmission production and the impact of those trends on vehicle fuel economy and CO2 emissions. 

Over the last 35 years, one trend is strikingly clear: automakers have consistently developed and commercialized 

new technologies that have provided more benefits to consumers. As discussed previously in Sections 2 and 3, the 

benefits provided by new technologies have varied over time. New technologies have been introduced for many 

reasons, including to increase fuel economy, reduce CO2 emissions, increase vehicle power and performance, 

increase vehicle content and weight, or some combination of all the above. 

A. TRENDS IN ENGINE POWER AND SIZE (CYLINDERS 

AND DISPLACEMENT) 

One of the most remarkable trends over the course of this report is the increase in vehicle 

power since the early 1980s. From 1975 through the early 1980s, average horsepower 

decreased, in combination with lower vehicle weight (see Table 2.1 and Figure 2.3) and smaller 

engine displacement (see below). Since the early 1980s, the average new vehicle horsepower 

has more than doubled. Average horsepower climbed consistently from MY 1982 to MY 2008. 

Since MY 2008, horsepower trends have been less consistent, but still appear to be generally 

increasing. Horsepower is projected to reach a new high in MY 2014, at 233 hp. The trend in 

horsepower is mainly attributable to improvements in engine technology, but increasing 

production of larger vehicles and an increasing percentage of truck production have also 

influenced the increase of average new vehicle horsepower. The trend in average new vehicle 

horsepower is shown in Figure 5.1. 

Engine size, as measured by total displacement, is also shown in Figure 5.1. Three general 

phases in engine displacement are discernible. From MY 1975 to 1987, the average engine 

displacement of new vehicles dropped dramatically by nearly 40%. From MY 1988 to 2004, 

displacement generally grew slowly, but the trend reversed in 2005 and engine displacement 

has been slowly decreasing since. In MY 2013, engine displacement was just slightly higher 

than the lowest average displacement in MY 1987. 

The contrasting trends in horsepower (all-time high) and engine displacement (near an all-time 

low) highlight the continuing improvement in engines due to introduction of new 

technologies (e.g., port fuel injection) and smaller engineering improvements that are not 

tracked by this report (e.g., reduced internal friction). One additional way to examine the 

relationship between engine horsepower and displacement is to look at the trend in specific 

power, which is a metric to compare the power output of an engine relative to its size. Here, 

engine specific power is defined as horsepower divided by displacement. 

52 
 

 

 

 

 

 

Figure 5.1 

Engine Power and Displacement 

175 

200 

225 

250 

275 

100 

150 

200 

Displacement 

Horsepower 

125 

175 

225 

Average Specific 

Power 

0.6 

0.8 

1.0 

1.2 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Cubic inches HP/Displacement HP 

Model Year 

Since the beginning of this report, the average specific power of engines across the new vehicle 

fleet has increased at a remarkably steady rate, as shown in Figure 5.1. Since MY 1975, the 

specific power of new vehicle engines has increased, on average, by 0.02 horsepower per cubic 

inch every year. 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, although the projected MY 2014 specific power is flat. 

Turbocharged engines, direct injection, higher compression ratios, and many other engine 

technologies are likely to continue increasing engine specific power. 

Figure 5.2 summarizes three important engine metrics, each of which has shown a remarkably 

linear change over time. Specific power, as discussed above, has increased more than 150% 

since MY 1975 and at a very steady rate. The amount of fuel consumed by an engine, relative 

to the total displacement, has fallen about 15% since MY 1975, and fuel consumption relative 

to engine horsepower has fallen nearly 65% since MY 1975. Taken as a whole, the trend lines 

in Figure 5.2 clearly show that engine improvements over time have been steady, continual, 

and have resulted in impressive improvements to internal combustion engines. 

53 
 

 

 

 

 

 

 

 

 

Figure 5.2 

Percent Change for Specific Engine Metrics 

−50% 

0% 

50% 

100% 

150% 

Percent change since 1975 

HP/Displacement 

Fuel Consumption/HP 

Fuel Consumption/Displacement 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

Another basic engine design parameter that is useful to explore is the number of engine 

cylinders. Since 1975, there have been significant changes to the number of cylinders in new 

vehicles, as shown in Figure 5.3. In the mid and late 1970s, the 8-cylinder engine was 

dominant, accounting for over half of new vehicle production. In MY 1980 there was a 

significant change in the market, as 8-cylinder engine production share dropped from 54% to 

26% and 4-cylinder production share increased from 26% to 45%. The 4-cylinder engine then 

continued to lead the market until overtaken by 6-cylinder engines in MY 1992. Model year 

2009 marked a second major shift in engine production, as 4-cylinder engines once again 

became the production leader with 51% of the market (an increase of 13% in a single year), 

followed by 6-cylinder engines with 35%, and 8-cyinder engines at an all-time low of 12%. 

Production of 4-cylinder engines decreased slightly in MY 2010 and MY 2011, but increased 

back to a new high of 56% in MY 2013. Engine displacement per cylinder has been relatively 

stable over the time of this report (around 35 cubic inches per cylinder since 1980), so the 

reduction in overall new vehicle engine displacement shown in Figure 5.1 is almost entirely 

due to the shift towards engines with fewer cylinders. In MY 2014, the sales of three cylinder 

engines is projected to be less than 20,000, but growing. 

54 
 

 

 

Figure 5.3 

Production Share by Number of Engine Cylinders 

Number of 

Cylinders 

Production Share 

0% 

20% 

40% 

60% 

80% 

100% 

Other 

8 

6 

4 

3 

1975 1980 1985 1990 1995 2000 2005 2010 2015
 

Model Year
 

55 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B. TRENDS IN FUEL DELIVERY METHODS AND 

VALVETRAINS 

One aspect of engine design that has changed significantly over time is how fuel is delivered 

into the engine. In the 1970s and early 1980s, nearly all engines used carburetors to meter fuel 

delivered to the engine. Carburetors were replaced over time with throttle body injection 

systems (TBI) and port fuel injection systems. More recently, engines with gasoline direct 

injection (GDI) have begun to replace engines with port fuel injection. Engines using GDI 

were first introduced into the market in very limited amounts in MY 2007, and only 6 years 

later GDI engines were installed in about 30% of new vehicles in MY 2013 and are projected 

to achieve a 38% market share in MY 2014. 

Another key aspect of engine design is the valvetrain. The number of valves per cylinder and 

the ability to alter valve timing during the combustion cycle can result in significant power and 

efficiency improvements. This report began tracking multi-valve engines (i.e., engines with 

more than 2 valves per cylinder) for cars in MY 1986 (and for trucks in MY 1994), and since 

that time nearly the entire fleet has converted to multi-valve design. While some three and five 

valve engines have been produced, the vast majority of multi-valve engines are based on 4 

valves per cylinder. In addition to the number of valves per cylinder, engine designs have 

evolved that allow engine valves to vary the timing when they are opened or closed with 

respect to the combustion cycle, creating more flexibility to control engine efficiency, power, 

and emissions. This report began tracking variable valve timing (VVT) for cars in MY 1990 

(and for trucks in MY 2000), and since then nearly the entire fleet has adopted this 

technology. Figure 5.4 shows the evolution of engine technology, including fuel delivery 

method and the introduction of VVT and multi-valve engines. 

As clearly shown in Figure 5.4, fuel delivery and valve-train technologies have often developed 

over the same time frames. 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 VVT technology. Engines with GDI are 

almost exclusively using multi-valve and VVT technology. These four engine groupings, or 

packages, represent a large share of the engines produced over the lifetime of the Trends 

database. 

Figure 5.5 shows the changes in specific power and fuel consumption between 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 two-valve port fixed engines, to multivalve port VVT engines, and finally to GDI engines. Some of the increase for GDI engines 

may also be due to the fact that GDI engines are often paired with turbochargers to further 

increase power. Figure 5.5 also shows the reduction in fuel consumption per horsepower for 

each of the four engine packages. 

56 
 

Figure 5.4

Production Share by Engine Technology 

Car 

0% 

25% 

50% 

75% 

100% 

Production Share

0% 

25% 

50% 

75% 

100% 

Truck 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

6 

5 

11 

7 

3 

10 

1 

4 

8 

11 

6 

5 

7 

3 

1 

11 11 

9 

2 

8 

10 

Model Year 

Fuel Delivery Valve Timing Number of Valves Key 

Carbureted Fixed Two-Valve 1 

Multi-Valve 2 

Throttle Body Injection Fixed Two-Valve 3 

Multi-Valve 4 

Port Fuel Injection Fixed Two-Valve 5 

Multi-Valve 6 

Variable Two-Valve 7 

Multi-Valve 8 

Gasoline Direct Injection 

(GDI) 

Fixed Multi-Valve 9 

Variable Multi-Valve 10 

Diesel 11 

57 
 

Figure 5.5 

Engine Metrics for Different Engine Technology Packages 

0.8 

1.2 

1.6 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Specific Power (HP/Displacement) 

Carb 

Technology 

Fixed and 

Two-Valve 

Technology 

Multi-Valve 

Variable and 

GDI 

Model Year 

0.06 

Fuel Consumption/HP ((gal/100 mi)/HP) 

0.05 

0.04 

0.03 

0.02 

Technology 

Multi-Valve 

Variable and 

GDI 

Technology 

Fixed and Two-Valve 

Carb 

1975 1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

58 
 

 

 

 

 

 

 

 

 

C. NEW POWERTRAIN STRATEGIES: TURBO 

DOWNSIZING, HYBRIDS, AND DIESELS 

Two powertrain strategies that are relatively new to this report are turbo downsizing and 

hybridization. Vehicles that employ turbo downsizing use a smaller displacement engine with a 

turbocharger in place of a larger naturally aspirated engine. Hybrid vehicles feature larger 

batteries that provide a second source of on-board power. Diesel engines, while certainly not 

new to the market or to this report, are also included in this section of the report due to the 

increased interest in diesel vehicles. 

Turbo-downsizing 

Many manufacturers have introduced engines that are considered “turbo downsized” engines. 

This group of engines generally has three common features: a smaller displacement than the 

engines they are replacing, turbochargers, and (often, but not always) GDI. Turbo downsized 

engines are an approach to engine design that provides increased fuel economy by using a 

smaller engine for most vehicle operation, while retaining the ability to provide more power 

via the turbocharger, when needed. 

Turbocharged engines are projected to capture approximately 16% of new vehicle production 

in MY 2014, with 10 of the 13 largest manufacturers (as discussed in Section 4) offering 

turbocharged engine packages. This is a significant increase in market penetration over the last 

decade, and it is a trend that appears to be accelerating rapidly, as shown in Figure 5.6. Prior 

to the last few years, turbochargers (and superchargers) were available, but generally only on 

high performance, low volume vehicles. It is only in the last few years that turbochargers have 

been available as part of a downsized turbo vehicle package, many of which are now available 

in more mainstream vehicles. The sales of these vehicles are driving the increase in 

turbochargers across new vehicles. Both cars and trucks have rapidly added turbocharged 

engine packages, as shown in Figure 5.6. Projected 2014 data does show a drop in 

turbocharged trucks from 12.1% to 11.1%, however after a 6% market share increase the year 

before the trend still appears to be generally positive for turbocharged trucks. 

Turbochargers are most frequently combined with 4-cylinder engines. Excluding diesel 

engines, over 75% of turbocharged engines are combined with 4-cylinder engines and about 

18% are combined with 6-cylinder engines. Nearly 60% of turbocharged engines are projected 

to be installed in 4-cylinder cars in MY 2014. The overall breakdown of turbocharger 

distribution in the new vehicle fleet is shown in Table 5.1. 

In current engines, turbochargers are often being used in combination with GDI to allow for 

more efficient engine operation and to increase the resistance to engine knock (the use of 

variable valve timing also helps to reduce turbo lag). In MY 2014, 80% of new vehicles with 

gasoline turbocharged engines also use GDI. 

59 
 

 

 

Figure 5.6 

Market Share of Gasoline Turbo Vehicles 

15% 

Production Share 

10% 

5% 

0% 

Trucks 

Cars 

1995 2000 2005 2010 2015 

Model Year 

Table 5.1 

Distribution of MY 2014 Turbocharged Engines (Excludes Diesel) 

Category Turbo Share 

Car 

4-cylinder Car 64.7% 

6-cylinder Car 5.0% 

8-cylinder Car 3.6% 

Other Car 1.0% 

Truck 

4-cylinder Truck 13.1% 

6-cylinder Truck 11.1% 

8-cylinder Truck 1.5% 

60 
 

 

 

 

 

 

Figure 5.7 

Distribution of Gasoline Turbo Vehicles by Displacement and Horsepower, MY 2010 - 2014 

Horsepower Displacement (cubic inches) 

Production (000) 

1,000
 

750
 

500
 

250
 

0
 

1,000
 

750
 

500
 

250
 

0
 

1,000
 

750
 

500
 

250
 

0
 

1,000
 

750
 

500
 

250
 

0
 

1,000
 

750
 

500
 

250
 

0
 

2010 2011 2012 2013 2014 

Mean 

Displacement, 

all trucks 

Mean 

Displacement, 

all trucks 

Mean 

Displacement, 

all cars 

Mean 

Displacement, 

all cars 

Mean 

Displacement, 

all cars 

Mean 

Displacement, 

all cars 

Mean 

Displacement, 

all trucks 

Mean 

Displacement, 

all trucks 

Mean HP, 

all trucks 

Mean HP, 

all cars 

Mean HP, 

all cars 

Mean HP, 

all cars 

Mean HP, 

all cars 

Mean HP, 

all trucks 

Mean HP, 

all trucks 

Mean HP, 

all trucks 

Mean HP, 

all cars 

Mean HP, 

all trucks 

Mean 

Displacement, 

all cars 

Mean 

Displacement, 

all trucks 

0 100 200 300 400 500 600 700 800 50 100 150 200 250 300 350 400
 

Figure 5.7 examines the distribution of engine displacement and power of turbocharged 

engines for MY 2010 (top) to MY 2014 (bottom). Note that the production values for cars and 

trucks in each bar are additive, e.g., there are projected to be nearly 750,000 gasoline cars with 

turbochargers in the 200-300 horsepower range in MY 2014, with another 250,000 gasoline 

trucks with turbochargers in the same horsepower range. In MY 2010, turbochargers were 

used mostly on cars, and were available on engines both above and below the average engine 

displacement. The biggest increase in turbocharger use over the last few years has been in cars 

with engine displacement well below average displacement. In addition, many more engines 

with turbochargers are at or below the new vehicle average horsepower, for both cars and 

Truck 

Car 

61 
 

 

 

trucks. This trend towards adding turbochargers to smaller, less powerful engines reinforces 

the conclusion that most turbochargers are currently being used for turbo downsizing, and not 

simply just to add power for performance vehicles. 

Hybrids 

Hybrid vehicles utilize larger battery packs, electric motor(s), and other components that 

increase vehicle fuel economy for several reasons including: 1) regenerative braking can 

capture energy that is otherwise lost in conventional friction braking to charge the battery, 2) 

two sources of on-board power can allow the engine to be operated at or near its peak 

efficiency more often, and 3) the engine can be shut off at idle. The introduction of the first 

hybrid into the U.S. marketplace occurred in MY 2000. Since then, hybrids have slowly 

increased market share and are projected to reach 4.0% of all new vehicles produced in MY 

2014. Hybrid production has fluctuated from year to year, but the general trend has been 

increasing over time as shown in Figure 5.8. A large factor in the fluctuating hybrid 

production is the fact that hybrid sales are still largely dominated by one vehicle, the Toyota 

Prius. Production of the Toyota Prius, like many other vehicles produced in Japan, was 

impacted by the earthquake and tsunami that hit Japan in 2011, as well as by a shortened 

model year in MY 2009 due to the introduction of a redesigned vehicle. 

Figure 5.8 

Hybrid Production MY 2000 - 2014 (With 3-Year Moving Average)
 

600,000 

400,000 

Production

200,000 

0 

Car Hybrids 

Truck Hybrids 

2000 2005 2010 2015 

Model Year 

62 
 

 

 

 

 

The first hybrid vehicle was introduced in the U.S. in MY 2000 as low production, specialty 

vehicle with very high fuel economy. Over time, more hybrids models were introduced into 

the market, and hybrids represented a broader range of vehicle types. Hybrid powertrains are 

now frequently offered as options on many popular models and are nearly indistinguishable 

from their non-hybrid relatives. Most hybrids provide higher fuel economy than comparable 

vehicles, although some hybrids have been offered as more performance-oriented vehicles with 

more minor fuel economy improvements. 

Figure 5.9 shows the production-weighted distribution of fuel economy for all hybrid cars by 

year. Hybrid cars, on average, have fuel economy more than 50% higher than the average nonhybrid car in MY 2014. As a production weighted average, hybrid cars achieved 42 mpg for 

MY 2014, while the average non-hybrid car achieved about 27 mpg. From MY 2000 to MY 

2014, the number of hybrid models available has increased from 1 to nearly 40. The increasing 

spread between the highest and lowest fuel economy of available hybrid cars is a reflection of 

the widening availability of hybrid models. Figure 5.9 is presented for cars only since the 

production of hybrid trucks has been limited. 

Figure 5.9 

Hybrid Adjusted Fuel Economy Distribution by Year, Cars Only 

60 

Adjusted Fuel Economy (MPG) 

50 

40 

30 

20 

10 

0 

Average Non-Hybrid Car Lowest Hybrid Car 

Average Hybrid Car 

Highest Hybrid Car 

2000 2005 2010 2015 

Model Year 

While the average fuel economy of hybrid cars remains higher than the average fuel economy 

of non-hybrid cars, the difference appears to be narrowing. Average hybrid car fuel economy 

has been relatively stable since MY 2001, while the fuel economy of the average non-hybrid car 

has increased 25%. Figure 5.10 further explores this trend by examining midsize cars. While 

generally this report has moved away from using vehicle sub-classes such as midsize sedans, it is 

63 
 

 

 

 

 

a well-established and recognized category and about 65% of hybrid cars are in the midsize 

class. Comparing average midsize hybrids to average midsize non-hybrid cars, gasoline only, is 

an apples-to-apples comparison. 

Figure 5.10 

Hybrid and Non-Hybrid Fuel Economy for Midsize Cars, MY 2000 - 2014 

0 

10 

20 

30 

40 

50 

2000 2005 2010 

Adjusted Fuel Economy (MPG) 

2015 

Average Non-Hybrid Midsize Car 

Average Hybrid Midsize Car 

Model Year 

Since MY 2004, the difference in fuel economy between the average hybrid midsize car and 

the average non-hybrid midsize gasoline car has narrowed from about 24 mpg to 15 mpg. The 

primary reason for this trend is continued improvements to the internal combustion engine. 

Additionally, many technologies introduced or emphasized in early hybrids, such as improved 

aerodynamics, low rolling resistance tires, and increased use of lightweight materials, have also 

become more common on non-hybrid vehicles. This lower fuel economy differential between 

midsize hybrid cars and midsize non-hybrid cars may be one reason why hybrid sales have 

grown slowly in recent years. 

One unique design aspect of hybrids is the ability to use regenerative braking to capture some 

of the energy lost by a vehicle during braking. The recaptured energy is stored in a battery and 

is then used to help propel the vehicle, generally during vehicle acceleration. This process 

results in significantly higher city fuel economy ratings for hybrid vehicles compared to nonhybrid vehicles, and in fact the city fuel economy of many hybrids is about equal to their 

highway fuel economy. Figure 5.11 shows the ratio of highway to city fuel economy for hybrid 

cars and trucks. Hybrid models have a ratio of highway to city fuel economy near 1.0 (meaning 

64 
 

 

 

 

 

 

the city and highway fuel economy are nearly equivalent) which is much lower than the 1.4 

ratio of highway to city fuel economy for non-hybrid models. This is one aspect of operating a 

hybrid that is fundamentally different from a conventional vehicle and appears to be relatively 

steady over time. 

Figure 5.11 

Highway/City Fuel Economy Ratio for Hybrids and Non-Hybrids 

0.8 

1.0 

1.2 

1.4 

Adjusted Highway/Adjusted City 

Non-Hybrid Car 

Non-Hybrid Truck 

Hybrid Car 

Hybrid Truck 

2000 2005 2010 2015 

Model Year 

The relationship between hybrids and non-hybrids is clearer if vehicles of the same footprint 

are compared directly. As shown in Figure 5.12, the fuel consumption of vehicles increases as 

the footprint increases at about the same rate for both hybrid and non-hybrid vehicles. 

Hybrids do achieve a higher percentage improvement in smaller vehicles, and achieve more 

than 30% lower fuel consumption, on average, for vehicles with a footprint of 45 square feet, 

which is about the size of a standard midsize sedan. The percent improvement figure at the 

bottom of Figure 5.12 describes the fuel consumption improvement for hybrid vehicles as 

compared to conventional vehicles over the range of footprints for which both hybrid and 

conventional vehicles are available. It depicts the percentage difference between the ‘best fit’ 

lines for hybrid vehicles and conventional vehicles shown in the upper part of Figure 5.12. 

65 
Figure 5.12

Percent Improvement in Adjusted Fuel Consumption for Hybrid Vehicles, MY 2013

10 

Fuel Consumption (gal/100 miles) 

Percent Improvement 

8 

6 

4 

Non-Hybrid 

Vehicles 

Hybrid 

Vehicles 

2 

40 60 

Footprint (sq ft) 

80 

50% 

25% 

0% 

40 60 80 

Footprint (sq ft) 

66 
 

 

 

 

 

 

 

 

 

 

 

Diesels 

While diesel engines are not a new technology, interest in diesel engines for light duty 

passenger applications has grown in recent years. Light duty diesel vehicles are projected to 

increase to about 1.5% of new vehicle production for MY 2014, the highest level since MY 

1984. As with hybrid vehicles, diesels generally achieve higher fuel economy than non-diesel 

vehicles. However, for diesel vehicles available in MY 2013, the percent improvement is more 

pronounced in vehicles with a smaller footprint than in vehicles with a larger footprint. This is 

partly explained due to the fact that MY 2013 larger footprint diesel offerings are limited to 

higher power offerings from luxury manufacturers. The relationship between diesel vehicles 

and all new vehicles is shown in Figure 5.13. 

While diesel engines generally achieve higher fuel economy than comparable gasoline vehicles, 

there is less of an advantage in terms of CO2 emissions. Some of the fuel economy benefit of 

diesel engines is negated by the fact that diesel fuel contains about 15% more carbon per 

gallon, and thus emits more CO2 per gallon burned than gasoline. Figure 5.14 shows the 

impact of diesel vehicles on CO2 emissions by comparing the CO2 emissions of MY 2013 

diesel and gasoline vehicles by footprint. 

Other Technologies 

Table 5.2.1 presents comprehensive annual data for the historic MY 1975-2014 database for all 

of the engine technologies and parameters discussed above and several additional technologies. 

This is the first year that this report has included engine stop/start technology (for non-hybrid 

vehicles), and already stop/start technology is projected to be included on more than 4% of 

new non-hybrid vehicle production in MY 2014 (note that total use of stop/start is nearly 9% 

of the market since hybrids typically utilize stop/start as well). Cylinder deactivation, another 

technology not discussed above, has also grown to capture a projected 11.7% of production in 

MY 2014. Tables 5.2.2 and 5.2.3 provide the same data for cars only and trucks only, 

respectively. This data, and additional data, is further broken down in Appendices E through I. 

67 
Figure 5.13 

Percent Improvement in Adjusted Fuel Consumption for Diesel Vehicles, MY 2013

10.0 

Percent Improvement Fuel Consumption (gal/100 mile) 

7.5 

5.0 Non-Diesel 

Vehicles 

2.5 

Diesel 

Vehicles 

40 60 

Footprint (sq ft) 

80 

0% 

25% 

50% 

40 

Footprint (sq ft) 

60 80 

68 
Figure 5.14 

Percent Improvement in CO2 Emissions for Diesel Vehicles, MY 2013

800 

Percent Improvement CO2 Emissions (g/mile) 

600 

200 

400 Non-Diesel 

Vehicles 

Diesel 

Vehicles 

40 

Footprint (sq ft) 

60 80 

50% 

0% 

25% 

40 

Footprint (sq ft) 

60 80 

69 
 

 

Table 5.2.1 

Engine Technologies and Parameters, Both Cars and Trucks 

Model 

Year 

Powertrain Fuel Delivery Method 

Avg. 

No. of 

Cylinders CID HP 

MultiValve VVT CD Turbo 

NonHybrid 

Stop/ 

Gasoline Start 

Gasoline 

Hybrid Diesel Carbureted GDI Port TBI Diesel 

1975 99.8% - 0.2% 95.7% - 4.1% 0.0% 0.2% 6.82 293 137 - - - - -

1976 99.8% - 0.2% 97.3% - 2.5% 0.0% 0.2% 6.87 294 135 - - - - -

1977 99.6% - 0.4% 96.2% - 3.4% 0.0% 0.4% 6.94 287 136 - - - - -

1978 99.1% - 0.9% 95.2% - 3.9% 0.0% 0.9% 6.69 266 129 - - - - -

1979 98.0% - 2.0% 94.2% - 3.7% 0.1% 2.0% 6.53 252 124 - - - - -

1980 95.7% - 4.3% 89.7% - 5.2% 0.8% 4.3% 5.59 198 104 - - - - -

1981 94.1% - 5.9% 86.7% - 5.1% 2.4% 5.9% 5.50 193 102 - - - - -

1982 94.4% - 5.6% 80.6% - 5.8% 8.0% 5.6% 5.43 188 103 - - - - -

1983 97.3% - 2.7% 75.2% - 7.3% 14.8% 2.7% 5.54 193 107 - - - - -

1984 98.2% - 1.8% 67.6% - 11.9% 18.7% 1.8% 5.49 190 109 - - - - -

1985 99.1% - 0.9% 56.1% - 18.2% 24.8% 0.9% 5.46 189 114 - - - - -

1986 99.6% - 0.4% 41.4% - 32.5% 25.7% 0.4% 5.26 180 114 3.4% - - - -

1987 99.7% - 0.3% 28.4% - 39.9% 31.4% 0.3% 5.17 175 118 10.6% - - - -

1988 99.9% - 0.1% 15.0% - 50.6% 34.3% 0.1% 5.31 180 123 14.0% - - - -

1989 99.9% - 0.1% 8.7% - 57.3% 33.9% 0.1% 5.36 185 129 16.9% - - - -

1990 99.9% - 0.1% 2.1% - 70.8% 27.0% 0.1% 5.39 185 135 23.1% - - - -

1991 99.9% - 0.1% 0.6% - 70.6% 28.7% 0.1% 5.32 184 138 23.1% - - - -

1992 99.9% - 0.1% 0.5% - 81.6% 17.8% 0.1% 5.50 191 145 23.3% - - - -

1993 100.0% - - 0.3% - 85.0% 14.6% - 5.50 191 147 23.5% - - - -

1994 100.0% - 0.0% 0.1% - 87.7% 12.1% 0.0% 5.58 197 152 26.7% - - - -

1995 100.0% - 0.0% - - 91.6% 8.4% 0.0% 5.59 196 158 35.6% - - - -

1996 99.9% - 0.1% - - 99.3% 0.7% 0.1% 5.59 197 164 39.3% - - 0.2% -

1997 99.9% - 0.1% - - 99.5% 0.5% 0.1% 5.65 199 169 39.6% - - 0.4% -

1998 99.9% - 0.1% - - 99.8% 0.1% 0.1% 5.63 199 171 40.9% - - 0.8% -

1999 99.9% - 0.1% - - 99.9% 0.1% 0.1% 5.75 203 179 43.4% - - 1.4% -

2000 99.8% 0.0% 0.1% - - 99.8% 0.0% 0.1% 5.74 200 181 44.8% 15.0% - 1.3% -

2001 99.7% 0.1% 0.1% - - 99.9% - 0.1% 5.76 201 187 49.0% 19.6% - 2.0% -

2002 99.6% 0.2% 0.2% - - 99.8% - 0.2% 5.77 203 195 53.3% 25.3% - 2.2% -

2003 99.5% 0.3% 0.2% - - 99.8% - 0.2% 5.79 204 199 55.5% 30.6% - 1.2% -

2004 99.4% 0.5% 0.1% - - 99.9% - 0.1% 5.90 212 211 62.3% 38.5% - 2.3% -

2005 98.6% 1.1% 0.3% - - 99.7% - 0.3% 5.75 205 209 65.6% 45.8% 0.8% 1.7% -

2006 98.1% 1.5% 0.4% - - 99.6% - 0.4% 5.73 204 213 71.7% 55.4% 3.6% 2.1% -

2007 97.7% 2.2% 0.1% - - 99.8% - 0.1% 5.64 203 217 71.7% 57.3% 7.3% 2.5% -

2008 97.4% 2.5% 0.1% - 2.3% 97.6% - 0.1% 5.56 199 219 76.4% 58.2% 6.7% 3.0% -

2009 97.2% 2.3% 0.5% - 4.2% 95.2% - 0.5% 5.21 183 208 83.8% 71.5% 7.3% 3.3% -

2010 95.6% 3.8% 0.7% - 8.3% 91.0% - 0.7% 5.27 188 214 85.5% 83.8% 6.4% 3.3% -

2011 97.1% 2.2% 0.8% - 15.4% 83.8% - 0.8% 5.35 192 230 86.4% 93.1% 9.5% 6.8% -

2012 96.0% 3.1% 0.9% - 22.7% 76.4% - 0.9% 5.12 180 222 91.9% 96.7% 8.1% 8.4% 0.6% 

2013 95.6% 3.5% 0.9% - 30.4% 68.7% - 0.9% 5.08 177 227 93.0% 97.6% 7.9% 14.1% 2.3% 

2014 94.5% 4.0% 1.5% - 37.9% 60.6% - 1.5% 5.17 182 233 93.7% 97.5% 11.7% 15.7% 4.6% 

70 
 

 

Table 5.2.2 

Engine Technologies and Parameters, Cars Only 

Model 

Year 

Powertrain Fuel Delivery Method 

Avg. 

No. of 

Cylinders CID HP 

MultiValve VVT CD Turbo 

NonHybrid 

Stop/ 

Gasoline Start 

Gasoline 

Hybrid Diesel Carbureted GDI Port TBI Diesel 

1975 99.8% - 0.2% 94.6% - 5.1% - 0.2% 6.71 288 136 - - - - -

1976 99.7% - 0.3% 96.6% - 3.2% - 0.3% 6.75 287 134 - - - - -

1977 99.5% - 0.5% 95.3% - 4.2% - 0.5% 6.85 279 133 - - - - -

1978 99.1% - 0.9% 94.0% - 5.1% - 0.9% 6.52 251 124 - - - - -

1979 97.9% - 2.1% 93.2% - 4.7% - 2.1% 6.38 238 119 - - - - -

1980 95.6% - 4.4% 88.7% - 6.2% 0.7% 4.4% 5.48 188 100 - - - - -

1981 94.1% - 5.9% 85.3% - 6.1% 2.6% 5.9% 5.36 182 99 - - - - -

1982 95.3% - 4.7% 78.4% - 7.2% 9.8% 4.7% 5.23 175 99 - - - - -

1983 97.9% - 2.1% 69.7% - 9.4% 18.8% 2.1% 5.39 182 104 - - - - -

1984 98.3% - 1.7% 59.1% - 14.9% 24.3% 1.7% 5.34 179 106 - - - - -

1985 99.1% - 0.9% 46.0% - 21.3% 31.8% 0.9% 5.29 177 111 - - - - -

1986 99.7% - 0.3% 34.4% - 36.5% 28.7% 0.3% 5.09 167 111 4.7% - - - -

1987 99.8% - 0.2% 26.5% - 42.4% 30.8% 0.2% 4.98 162 113 14.6% - - - -

1988 100.0% - 0.0% 16.1% - 53.7% 30.2% 0.0% 5.02 161 116 19.7% - - - -

1989 100.0% - 0.0% 9.6% - 62.2% 28.1% 0.0% 5.07 163 121 24.1% - - - -

1990 100.0% - 0.0% 1.4% - 77.4% 21.2% 0.0% 5.05 163 129 32.8% 0.6% - - -

1991 99.9% - 0.1% 0.1% - 77.2% 22.6% 0.1% 5.05 164 133 33.2% 2.4% - - -

1992 99.9% - 0.1% 0.0% - 88.9% 11.0% 0.1% 5.23 171 141 34.0% 4.4% - - -

1993 100.0% - - 0.0% - 91.5% 8.5% - 5.19 170 140 34.8% 4.5% - - -

1994 100.0% - 0.0% - - 94.8% 5.2% 0.0% 5.20 169 144 39.9% 7.7% - - -

1995 99.9% - 0.1% - - 98.6% 1.3% 0.1% 5.23 168 153 51.4% 9.6% - - -

1996 99.9% - 0.1% - - 98.8% 1.1% 0.1% 5.18 167 155 56.4% 11.3% - 0.3% -

1997 99.9% - 0.1% - - 99.2% 0.8% 0.1% 5.10 165 156 58.4% 10.8% - 0.7% -

1998 99.8% - 0.2% - - 99.7% 0.1% 0.2% 5.15 167 160 59.6% 17.4% - 1.4% -

1999 99.8% - 0.2% - - 99.8% 0.1% 0.2% 5.21 168 164 63.2% 16.4% - 2.5% -

2000 99.7% 0.1% 0.2% - - 99.7% 0.1% 0.2% 5.22 168 168 63.2% 22.2% - 2.2% -

2001 99.5% 0.2% 0.2% - - 99.8% - 0.2% 5.19 167 169 65.3% 26.9% - 3.3% -

2002 99.3% 0.3% 0.4% - - 99.6% - 0.4% 5.12 167 173 69.9% 32.8% - 3.9% -

2003 99.1% 0.6% 0.3% - - 99.7% - 0.3% 5.13 166 176 73.4% 39.8% - 2.0% -

2004 98.9% 0.9% 0.3% - - 99.7% - 0.3% 5.16 170 184 77.1% 43.7% - 3.6% -

2005 97.6% 1.9% 0.4% - - 99.6% - 0.4% 5.08 168 183 77.2% 49.4% 1.0% 2.4% -

2006 97.9% 1.5% 0.6% - - 99.4% - 0.6% 5.17 173 194 81.3% 58.2% 2.0% 3.2% -

2007 96.7% 3.2% 0.0% - - 99.7% - 0.0% 5.00 167 191 84.6% 63.3% 0.9% 3.6% -

2008 96.7% 3.3% 0.1% - 3.1% 96.9% - 0.1% 4.97 166 194 88.0% 62.7% 2.0% 4.5% -

2009 96.4% 2.9% 0.6% - 4.2% 95.2% - 0.6% 4.70 157 186 92.2% 79.1% 1.8% 4.0% -

2010 93.6% 5.5% 0.9% - 9.2% 89.9% - 0.9% 4.70 158 190 93.8% 91.8% 2.1% 4.1% -

2011 95.6% 3.4% 0.9% - 18.4% 80.7% - 0.9% 4.74 161 200 94.6% 94.9% 1.3% 8.2% -

2012 94.4% 4.6% 1.0% - 27.8% 71.2% - 1.0% 4.54 151 192 98.2% 97.7% 1.7% 9.7% 0.9% 

2013 93.5% 5.3% 1.2% - 37.3% 61.5% - 1.2% 4.51 148 198 98.4% 98.1% 1.9% 15.3% 3.0% 

2014 92.6% 6.0% 1.5% - 42.5% 56.0% - 1.5% 4.55 150 201 98.0% 97.6% 3.1% 18.7% 6.2% 

71 
 

 

Table 5.2.3 

Engine Technologies and Parameters, Trucks Only 

Model 

Year 

Powertrain Fuel Delivery Method 

Avg. 

No. of 

Cylinders CID HP 

MultiValve VVT CD Turbo 

NonHybrid 

Stop/ 

Gasoline Start 

Gasoline 

Hybrid Diesel Carbureted GDI Port TBI Diesel 

1975 100.0% - - 99.9% - - 0.1% - 7.28 311 142 - - - - -

1976 100.0% - - 99.9% - - 0.1% - 7.31 320 141 - - - - -

1977 100.0% - - 99.9% - - 0.1% - 7.28 318 147 - - - - -

1978 99.2% - 0.8% 99.1% - - 0.1% 0.8% 7.25 315 146 - - - - -

1979 98.2% - 1.8% 97.9% - - 0.3% 1.8% 7.05 299 138 - - - - -

1980 96.5% - 3.5% 94.9% - - 1.7% 3.5% 6.15 248 121 - - - - -

1981 94.4% - 5.6% 93.3% - - 1.1% 5.6% 6.15 247 119 - - - - -

1982 90.6% - 9.4% 89.9% - - 0.7% 9.4% 6.26 244 120 - - - - -

1983 95.2% - 4.8% 94.6% - - 0.6% 4.8% 6.07 232 118 - - - - -

1984 97.6% - 2.4% 95.0% - 2.0% 0.6% 2.4% 5.99 225 118 - - - - -

1985 98.9% - 1.1% 86.5% - 8.9% 3.5% 1.1% 5.97 225 124 - - - - -

1986 99.3% - 0.7% 59.4% - 22.1% 17.8% 0.7% 5.71 212 123 - - - - -

1987 99.7% - 0.3% 33.6% - 33.3% 32.8% 0.3% 5.69 211 131 - - - - -

1988 99.8% - 0.2% 12.4% - 43.2% 44.3% 0.2% 6.00 228 141 - - - - -

1989 99.8% - 0.2% 6.5% - 45.9% 47.5% 0.2% 6.04 234 146 - - - - -

1990 99.8% - 0.2% 3.8% - 55.0% 40.9% 0.2% 6.17 237 151 - - - - -

1991 99.9% - 0.1% 1.7% - 55.3% 42.8% 0.1% 5.95 229 150 - - - - -

1992 99.9% - 0.1% 1.6% - 65.7% 32.6% 0.1% 6.09 236 155 - - - - -

1993 100.0% - - 1.0% - 71.5% 27.5% - 6.13 235 160 - - - - -

1994 100.0% - - 0.4% - 76.2% 23.4% - 6.19 241 166 5.2% - - - -

1995 100.0% - - - - 79.4% 20.6% - 6.22 245 168 8.0% - - - -

1996 99.9% - 0.1% - - 99.9% - 0.1% 6.25 245 179 11.2% - - - -

1997 100.0% - 0.0% - - 100.0% - 0.0% 6.47 251 189 11.1% - - - -

1998 100.0% - 0.0% - - 100.0% - 0.0% 6.30 244 188 14.8% - - - -

1999 100.0% - 0.0% - - 100.0% - 0.0% 6.50 252 199 15.7% - - - -

2000 100.0% - - - - 100.0% - - 6.48 245 199 18.6% 4.6% - - -

2001 100.0% - - - - 100.0% - - 6.58 249 212 25.9% 9.3% - - -

2002 100.0% - - - - 100.0% - - 6.57 249 223 32.8% 16.0% - - -

2003 100.0% - - - - 100.0% - - 6.56 248 224 34.6% 19.7% - 0.2% -

2004 100.0% 0.0% 0.0% - - 100.0% - 0.0% 6.70 258 240 46.2% 32.9% - 0.8% -

2005 99.8% 0.1% 0.1% - - 99.9% - 0.1% 6.58 251 242 51.1% 41.2% 0.5% 0.7% -

2006 98.4% 1.5% 0.1% - - 99.9% - 0.1% 6.50 247 240 58.4% 51.5% 5.9% 0.6% -

2007 99.1% 0.8% 0.1% - - 99.9% - 0.1% 6.57 253 254 53.3% 48.7% 16.4% 1.0% -

2008 98.5% 1.3% 0.2% - 1.1% 98.7% - 0.2% 6.42 246 254 59.5% 51.6% 13.5% 1.0% -

2009 98.8% 0.9% 0.3% - 4.2% 95.4% - 0.3% 6.23 236 252 66.7% 56.0% 18.3% 1.7% -

2010 98.8% 0.9% 0.4% - 6.8% 92.9% - 0.4% 6.22 237 253 71.5% 70.5% 13.8% 1.8% -

2011 99.1% 0.4% 0.5% - 11.3% 88.1% - 0.5% 6.18 236 271 75.2% 90.7% 20.6% 4.9% -

2012 98.9% 0.4% 0.7% - 13.5% 85.8% - 0.7% 6.16 234 276 80.6% 94.9% 19.6% 6.1% 0.2% 

2013 99.1% 0.4% 0.5% - 18.6% 80.9% - 0.5% 6.05 227 277 83.6% 96.9% 18.0% 11.9% 1.1% 

2014 97.5% 0.8% 1.6% - 30.5% 67.8% - 1.6% 6.15 233 282 86.9% 97.2% 25.4% 11.1% 2.1% 

72 
 

 

 

 

 

 

 

 

 

 

 

D. TRENDS IN TRANSMISSION TYPES 

Transmission technologies have been rapidly evolving in new light duty vehicles. New 

transmission technologies have been gaining market share, and nearly all transmission types 

have been increasing the number of gears. Dual clutch transmission (DCTs), continuously 

variable transmissions (CVTs), and automatic transmissions with greater numbers of gears are 

increasing production shares across the fleet. 

Figure 5.15 shows the evolution of transmission production share for cars and trucks since MY 

1980. For this analysis, transmissions are separated into 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. 

Dual clutch transmissions are relatively new to the light duty vehicle market. DCTs are 

essentially automatic transmissions that operate internally much more like traditional manual 

transmissions. The two main advantages of DCTs are that they can shift very quickly and they 

can avoid some of the internal resistance of a traditional automatic transmission by 

eliminating the torque converter. Currently, automaker submissions to EPA do not explicitly 

identify DCTs as a separate transmission category. Thus, the introduction of DCTs shows up 

in Tables 5.3.1 through 5.3.3 as a slight increase in automatic transmissions without torque 

converters (although some DCTs may still be reported as traditional automatic transmissions). 

EPA’s long-term goal is to improve DCT data collection, and transmission classifications in 

general, and to be able to quantify DCTs in future Trends reports. 

Figure 5.15 shows transmission production share for the individual car and truck fleets, and 

begins with MY 1980 because EPA has incomplete data on the number of transmission gears 

for MY 1975 through 1978. In the early 1980s, 3 speed automatic transmissions, both with 

and without lockup torque converters (shown as L3 and A3 in Figure 5.15) were the most 

popular transmissions, but by MY 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 MY 1999 were equipped with an L4 transmission. After MY 1999, 

the production share of L4 transmissions slowly decreased as L5 and L6 transmissions were 

introduced into the market. Production of L5 and L6 transmissions combined passed the 

production of L4 transmissions in MY 2007). Interestingly, 5 speed transmissions were never 

the leading transmission technology in terms of production share. Currently, L6 transmissions 

are projected to be installed in over 60% of new vehicles produced in MY 2014, and the 

percentage of vehicles with L6 transmissions is still trending upwards. 

73 
 

 

 

Figure 5.15 

Transmission Production Share Production Share

100% 

75% 

50% 

25% 

0% 

A3 CVT 

L3 

L4 

L5 L6 

M4 

M5 

A4 

A6 

Other 

L8 L7 

M6 

Car 

100% 

75% 

50% 

A3 

CVT 

L3 

L5 L6 

M4 

M5 

A4 

A6 

M3 

L7 

L4 

L8 

M6 

Truck 

25% 

0% 

1980 1985 1990 1995 2000 2005 2010 2015 

Model Year 

Transmission Lockup? Number of Gears Key 

Continuously Variable 

Automatic 

Semi-Automatic 

Automated Manual 

No 3 A3 

4 A4 

5 A5 

6 A6 

Yes 2 L2 

3 L3 

4 L4 

5 L5 

6 L6 

7 L7 

8 L8 

CVT 

Manual 3 M3 

4 M4

5 M5

6 M6

Other Other 

74 
 

 

 

 

 

 

 

 

 

 

 

 

Continuously variable transmissions have shown a large increase in production. In MY 2013, 

14.8% of new vehicles were produced with CVTs, and production is expected to reach 19.3% 

in MY 2014. This is a significant increase considering that, as recently as MY 2006, CVTs 

were installed on less than 3% of vehicles produced. Automatic transmissions with 7 or more 

speeds have also been increasing, and are expected to be over 11% of production for MY 

2014. Manufacturers are publicly discussing the development of transmissions with as many as 

10 or more gears, so this is a trend that the authors also expect to continue. 

Figure 5.16 shows the average number of gears in new vehicle transmissions since MY 1980 

for automatic and manual transmissions. During that time, the average number of gears in a 

new vehicle has grown from 3.5 to a projected level of 6.1 in MY 2014. The average number of 

gears in new vehicles is climbing for car, trucks, automatic transmissions, and manual 

transmissions. 

Figure 5.16 

Average Number of Transmission Gears for New Vehicles (excluding CVTs)
 

Car Truck 

Average Number of Gears 

4 

5 

6 

1980 1985 1990 1995 2000 2005 2010 2015 

3 

1980 1985 1990 1995 2000 2005 2010 2015 

Manual 

Automatic 

Automatic 

Manual 

Model Year 

In MY 1980, automatic transmissions, on average, had fewer gears than manual transmissions. 

However, automatic transmissions have added gears faster than manual transmissions and now 

the average automatic transmission has more gears than the average manual transmission. 

There has also been a large shift away from manual transmissions. Manual transmission 

production peaked in MY 1980 at nearly 35% of production, and has since fallen to 3.5% in 

MY 2013. Today, manual transmissions are used primarily in small vehicles, some sports cars, 

and a few pickups. 

Generally, automatic transmissions have been less efficient than manual transmissions, largely 

75 
 

 

 

due to inefficiencies in the automatic transmission torque converter. Figure 5.17 examines this 

trend over time by comparing the fuel economy of automatic and manual transmission 

options where both transmissions were available in one model with the same engine. The 

average fuel economy of vehicles with automatic transmissions appears to have increased to a 

point where it is now approximately the same as the average fuel economy of vehicles with 

manual transmissions. Two contributing factors to this trend are that automatic transmission 

design has become more efficient (using earlier lockup and other strategies), and the number 

of gears used in automatic transmissions has increased much quicker than in manual 

transmissions. 

Figure 5.17 

Comparison of Manual and Automatic Transmission Adjusted Fuel Economy 

16 

18 

20 

22 

24 

26 

28 

1980 1990 2000 2010 

Adjusted Fuel Economy (MPG) 

1985 1995 2005 2015 

Manual 

Automatic 

Model Year 

76 
 

 

 

 

 

E. TRENDS IN 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 vehicles, as shown in Figure 5.18. In 

MY 1975, over 91% of new vehicles were produced with rear wheel drive. During the 1980s, 

production of rear wheel drive vehicles fell rapidly, to 26% in MY 1990. Since then, 

production of rear wheel drive vehicles has continued to decline, albeit at a slower rate, to a 

projected 13% for MY 2014. Current production of rear wheel drive vehicles is mostly limited 

to pickup trucks and some performance vehicles. 

As production of rear wheel drive vehicles declined, production of front wheel drive vehicles 

increased. Front wheel drive vehicle production was only 5.3% of new vehicle production in 

MY 1975, but it became the most popular drive technology across new vehicles in MY 1985, 

and has remained so since. Since MY 1986, production of front wheel drive vehicles has 

remained, on average, at approximately 55% of production. 

Four wheel drive vehicles (including all wheel drive), have slowly but steadily grown across new 

vehicle production. From 3.3% in MY 1975 to a projected 31% in MY 2014, four wheel drive 

production has steadily grown at approximately 0.6% per year, on average. The majority of 

four wheel drive vehicles are pickup trucks and truck SUVs, but there is also a small but slowly 

growing number of cars featuring four wheel drive (or more likely) all-wheel drive systems. 

77 
 

 

 

 

 

 

 

 

 

1990

100% 

Drive 

75% 

Four Wheel Drive 

50% Front Wheel Drive 

25% Rear Wheel Drive 

0% 

1975 1975

1980 19801985 1985

Minivan/Van Truck SUV 1990 1975 2000

Pickup 

100% 

75% 

50% 

25% 

0% 

1995

1980

2005

1990

1995

20002005

1985

2010 2010

2015 2015

1995

2000 1975 1975

1980 1980 2005

1985 1985 2010

2015 1990 1990

1995 199520002005 20052010 20102015 

20002015 

Figure 5.18 

Front, Rear, and Four Wheel Drive Usage - Production Share by Vehicle Type 

Car Car SUV 

100% 

75% 

50% 

25% 

0% 

There are noticeable differences in fuel economy between vehicles with different drive types. 

Figure 5.19 shows the fuel consumption of MY 2013 vehicles separated by drive type and 

footprint. Rear wheel drive vehicles and four wheel drive vehicles have on average the same 

fuel consumption for equivalent footprint vehicles. Front wheel drive vehicles have much 

lower fuel consumption than rear wheel drive or four wheel drive vehicles of the same 

footprint. For 45 square foot vehicles, front wheel drive vehicles have fuel consumption about 

22% lower. There are certainly other factors involved (the rear wheel drive vehicles are likely 

more performance oriented, for example), but this is a noticeable trend across new vehicle 

production. The points in Figure 5.19 are generated for each combination of adjusted fuel 

consumption and footprint. 

78 
Tables 5.3.1, 5.3.2, and 5.3.3 summarize transmission and drive technology production data 

by year for the combined car and truck fleet, cars only, and trucks only, respectively.

Figure 5.19 

Differences in Adjusted Fuel Consumption Trends for FWD, RWD, and 4WD/AWD Vehicles, MY 2013

10.0 

7.5 

Car 

Fuel Consumption (gal/100 miles)

5.0 

2.5 Four-Wheel Drive and 

All-Wheel Drive 

Front-Wheel Drive 

10.0 Rear-Wheel Drive 

7.5 

Truck 

5.0 

2.5 

20 40 60 80 

Footprint 

79 
 

 

 

Table 5.3.1 

Transmission and Drive Technologies, Both Cars and Trucks 

Model 

Year Manual 

Automatic 

with 

Lockup 

Automatic 

without 

Lockup CVT 

4 Gears 

or 

Fewer 

5 

Gears 

6 

Gears 

7 

Gears 

8 

Gears 

9 

Gears 

or 

More CVT 

Average 

Number 

of Gears 

Front 

Wheel 

Drive 

Rear 

Wheel 

Drive 

Four 

Wheel 

Drive 

1975 23.0% 0.2% 76.8% - 99.0% 1.0% - - - - - - 5.3% 91.4% 3.3% 

1976 20.9% - 79.1% - 100.0% - - - - - - - 4.6% 90.6% 4.8% 

1977 19.8% - 80.2% - 100.0% - - - - - - - 5.5% 89.8% 4.7% 

1978 22.7% 5.5% 71.9% - 92.7% 7.3% - - - - - - 7.4% 86.0% 6.6% 

1979 24.2% 7.3% 68.1% - 93.8% 6.2% - - - - - 3.3 9.2% 86.5% 4.3% 

1980 34.6% 18.1% 46.8% - 87.9% 12.1% - - - - - 3.5 25.0% 70.1% 4.9% 

1981 33.6% 33.0% 32.9% - 85.6% 14.4% - - - - - 3.5 31.0% 65.0% 4.0% 

1982 32.4% 47.8% 19.4% - 84.4% 15.6% - - - - - 3.6 37.0% 58.4% 4.6% 

1983 30.5% 52.1% 17.0% - 80.9% 19.1% - - - - - 3.7 37.0% 54.8% 8.1% 

1984 28.4% 52.8% 18.8% - 81.3% 18.7% - - - - - 3.7 42.1% 49.8% 8.2% 

1985 26.5% 54.5% 19.1% - 80.7% 19.3% - - - - - 3.8 47.8% 42.9% 9.3% 

1986 29.8% 53.5% 16.7% - 76.8% 23.2% - - - - - 3.8 52.6% 38.0% 9.3% 

1987 29.1% 55.4% 15.5% - 76.2% 23.8% - - - - - 3.9 57.7% 32.8% 9.6% 

1988 27.6% 62.2% 10.2% - 76.8% 23.2% - - - - - 3.9 60.0% 29.5% 10.5% 

1989 24.6% 65.5% 9.9% 0.1% 78.5% 21.4% 0.0% - - - 0.1% 3.9 60.2% 29.3% 10.5% 

1990 22.2% 71.2% 6.5% 0.0% 79.9% 20.0% 0.1% - - - 0.0% 4.0 63.8% 26.1% 10.1% 

1991 23.9% 71.6% 4.5% 0.0% 77.3% 22.6% 0.0% - - - 0.0% 4.0 59.6% 28.1% 12.3% 

1992 20.7% 74.8% 4.5% 0.0% 80.8% 19.2% 0.1% - - - 0.0% 4.0 58.4% 30.4% 11.2% 

1993 19.8% 76.5% 3.7% 0.0% 80.9% 19.0% 0.1% - - - 0.0% 4.0 59.9% 28.8% 11.3% 

1994 19.5% 77.6% 3.0% - 80.8% 19.0% 0.2% - - - - 4.1 55.6% 29.2% 15.2% 

1995 17.9% 80.7% 1.4% - 82.0% 17.7% 0.2% - - - - 4.1 57.6% 26.3% 16.2% 

1996 15.2% 83.5% 1.3% 0.0% 84.7% 15.1% 0.2% - - - 0.0% 4.1 60.0% 24.3% 15.7% 

1997 14.0% 85.5% 0.5% 0.0% 82.4% 17.3% 0.2% - - - 0.0% 4.1 56.1% 24.9% 19.0% 

1998 12.8% 86.7% 0.5% 0.0% 82.1% 17.7% 0.2% - - - 0.0% 4.1 56.4% 23.5% 20.1% 

1999 10.1% 89.4% 0.5% 0.0% 84.4% 15.3% 0.3% - - - 0.0% 4.1 55.8% 22.9% 21.3% 

2000 9.7% 89.5% 0.7% 0.0% 83.7% 15.8% 0.5% - - - 0.0% 4.1 55.5% 24.3% 20.2% 

2001 9.0% 90.3% 0.6% 0.1% 80.7% 18.5% 0.7% - - - 0.1% 4.2 53.8% 24.2% 22.0% 

2002 8.2% 91.4% 0.3% 0.2% 77.1% 21.6% 1.1% - - - 0.2% 4.2 52.7% 22.3% 25.0% 

2003 8.0% 90.8% 0.1% 1.1% 69.2% 28.1% 1.7% - - - 1.1% 4.3 50.7% 24.3% 25.0% 

2004 6.8% 91.8% 0.3% 1.2% 63.9% 31.8% 3.0% 0.2% - - 1.2% 4.4 47.7% 22.4% 29.8% 

2005 6.2% 91.5% 0.1% 2.3% 56.0% 37.3% 4.1% 0.2% - - 2.3% 4.5 53.0% 20.2% 26.8% 

2006 6.5% 90.6% 0.0% 2.8% 47.7% 39.2% 8.8% 1.4% - - 2.8% 4.6 51.9% 22.3% 25.8% 

2007 5.6% 87.1% 0.0% 7.2% 40.5% 36.1% 14.4% 1.5% 0.2% - 7.2% 4.8 54.3% 19.6% 26.1% 

2008 5.2% 86.8% 0.2% 7.9% 38.8% 31.9% 19.4% 1.8% 0.2% - 7.9% 4.8 54.2% 18.5% 27.3% 

2009 4.8% 85.5% 0.2% 9.4% 31.3% 32.2% 24.5% 2.5% 0.1% - 9.4% 5.0 62.9% 13.6% 23.5% 

2010 3.8% 84.1% 1.2% 10.9% 24.6% 23.5% 38.1% 2.7% 0.2% - 10.9 5.2 59.5% 13.8% 26.7% 

2011 3.2% 86.6% 0.3% 10.0% 14.2% 18.7% 52.4% 3.1% 1.7% - 10.0 5.6 53.8% 13.8% 32.4% 

2012 3.6% 83.7% 1.1% 11.6% 8.0% 18.2% 56.7% 2.8% 2.6% - 11.6 5.7 61.4% 10.9% 27.7% 

2013 3.5% 80.7% 1.2% 14.7% 5.2% 13.1% 60.0% 2.9% 4.1% - 14.7 5.9 59.1% 11.3% 29.6% 

2014 3.7% 75.9% 1.1% 19.3% 1.3% 7.2% 61.0% 3.4% 6.7% 1.1% 19.3 6.1 56.0% 12.8% 31.2% 

80
 
 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.3.2 

Transmission and Drive Technologies, Cars Only 

Model 

Year Manual 

Automatic 

with 

Lockup 

Automatic 

without 

Lockup CVT 

4 Gears 

or 

Fewer 

5 

Gears 

6 

Gears 

7 

Gears 

8 

Gears 

9 

Gears 

or 

More CVT 

Average 

Number 

of Gears 

Front 

Wheel 

Drive 

Rear 

Wheel 

Drive 

Four 

Wheel 

Drive 

1975 19.7% 0.3% 80.0% - 98.7% 1.3% - - - - - - 6.5% 93.5% -

1976 17.2% - 82.8% - 100.0% - - - - - - - 5.8% 94.2% -

1977 16.9% - 83.1% - 100.0% - - - - - - - 6.8% 93.2% -

1978 19.9% 7.1% 73.0% - 90.7% 9.3% - - - - - - 9.6% 90.4% -

1979 21.1% 8.8% 69.6% - 93.1% 6.9% - - - - - 3.3 11.9% 87.8% 0.3% 

1980 30.9% 16.8% 51.6% - 87.6% 12.4% - - - - - 3.5 29.7% 69.4% 0.9% 

1981 29.9% 33.3% 36.2% - 85.5% 14.5% - - - - - 3.5 37.0% 62.2% 0.7% 

1982 29.2% 51.3% 19.1% - 84.6% 15.4% - - - - - 3.6 45.6% 53.6% 0.8% 

1983 26.0% 56.7% 16.8% - 80.8% 19.2% - - - - - 3.7 47.1% 49.9% 3.1% 

1984 24.1% 58.3% 17.5% - 82.1% 17.9% - - - - - 3.7 53.5% 45.5% 1.0% 

1985 22.8% 58.9% 18.4% - 81.4% 18.6% - - - - - 3.7 61.1% 36.8% 2.1% 

1986 24.7% 58.1% 17.1% - 79.7% 20.3% - - - - - 3.8 70.7% 28.2% 1.0% 

1987 24.8% 59.7% 15.5% - 78.4% 21.6% - - - - - 3.8 76.4% 22.6% 1.1% 

1988 24.3% 66.2% 9.5% - 80.2% 19.8% - - - - - 3.8 80.9% 18.3% 0.8% 

1989 21.1% 69.3% 9.5% 0.1% 81.9% 17.9% 0.0% - - - 0.1% 3.9 81.6% 17.4% 1.0% 

1990 19.8% 72.8% 7.4% 0.0% 82.4% 17.5% 0.1% - - - 0.0% 3.9 84.0% 15.0% 1.0% 

1991 20.6% 73.7% 5.7% 0.0% 81.0% 18.9% 0.1% - - - 0.0% 3.9 81.1% 17.5% 1.3% 

1992 17.6% 76.4% 6.0% 0.0% 83.6% 16.3% 0.1% - - - 0.0% 3.9 78.4% 20.5% 1.1% 

1993 17.5% 77.6% 4.9% 0.0% 83.2% 16.6% 0.2% - - - 0.0% 4.0 80.6% 18.3% 1.1% 

1994 16.9% 78.9% 4.1% - 83.4% 16.3% 0.3% - - - - 4.0 81.3% 18.3% 0.4% 

1995 16.3% 81.9% 1.8% - 83.4% 16.2% 0.4% - - - - 4.1 80.1% 18.8% 1.1% 

1996 14.9% 83.6% 1.5% 0.0% 84.9% 14.7% 0.3% - - - 0.0% 4.1 83.7% 14.8% 1.4% 

1997 13.9% 85.2% 0.8% 0.1% 84.1% 15.5% 0.3% - - - 0.1% 4.1 83.8% 14.5% 1.7% 

1998 12.2% 87.4% 0.3% 0.1% 82.8% 16.8% 0.3% - - - 0.1% 4.1 82.9% 15.0% 2.1% 

1999 10.8% 88.6% 0.6% 0.0% 83.4% 16.1% 0.5% - - - 0.0% 4.1 83.2% 14.7% 2.1% 

2000 10.8% 88.1% 1.0% 0.0% 81.3% 17.9% 0.8% - - - 0.0% 4.1 80.4% 17.7% 2.0% 

2001 11.0% 88.0% 0.8% 0.2% 78.5% 20.2% 1.2% - - - 0.2% 4.2 80.3% 16.7% 3.0% 

2002 10.9% 88.4% 0.2% 0.4% 77.4% 20.3% 1.9% - - - 0.4% 4.2 82.9% 13.5% 3.6% 

2003 10.9% 87.7% - 1.4% 67.5% 27.9% 3.1% - - - 1.4% 4.3 80.9% 15.9% 3.2% 

2004 9.8% 88.2% 0.2% 1.7% 64.5% 28.4% 5.0% 0.4% - - 1.7% 4.4 80.2% 14.5% 5.3% 

2005 8.8% 88.4% 0.1% 2.8% 57.3% 33.7% 5.8% 0.4% - - 2.8% 4.5 79.2% 14.2% 6.6% 

2006 8.8% 88.4% 0.1% 2.7% 47.5% 35.4% 12.5% 1.9% - - 2.7% 4.7 75.9% 18.0% 6.0% 

2007 7.8% 82.5% 0.0% 9.7% 36.8% 34.7% 16.5% 1.9% 0.4% - 9.7% 4.8 81.0% 13.4% 5.6% 

2008 7.2% 81.7% 0.3% 10.8% 39.3% 28.2% 19.0% 2.2% 0.4% - 10.8 4.8 78.8% 14.1% 7.1% 

2009 6.2% 82.4% 0.3% 11.1% 35.1% 31.4% 19.3% 2.9% 0.2% - 11.1 4.9 83.5% 10.2% 6.3% 

2010 5.0% 79.5% 1.6% 13.9% 29.5% 20.2% 33.0% 3.1% 0.3% - 13.9 5.1 82.5% 11.2% 6.3% 

2011 4.6% 83.0% 0.5% 11.9% 15.8% 12.9% 53.8% 3.9% 1.6% - 11.9 5.6 80.1% 11.3% 8.6% 

2012 4.9% 78.8% 1.7% 14.6% 6.7% 14.8% 57.8% 3.2% 2.9% - 14.6 5.8 83.8% 8.8% 7.4% 

2013 4.9% 75.1% 1.8% 18.2% 5.5% 9.0% 59.8% 3.4% 4.2% - 18.2 5.9 83.1% 9.5% 7.4% 

2014 5.3% 66.6% 1.9% 26.2% 1.5% 4.3% 58.6% 4.1% 4.8% 0.6% 26.2 6.2 80.8% 10.6% 8.6% 

81
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 5.3.3 

Transmission and Drive Technologies, Trucks Only 

Model 

Year Manual 

Automatic 

with 

Lockup 

Automatic 

without 

Lockup CVT 

4 Gears 

or 

Fewer 

5 

Gears 

6 

Gears 

7 

Gears 

8 

Gears 

9 

Gears 

or 

More CVT 

Average 

Number 

of Gears 

Front 

Wheel 

Drive 

Rear 

Wheel 

Drive 

Four 

Wheel 

Drive 

1975 36.9% - 63.1% - 100.0% - - - - - - - - 82.8% 17.2% 

1976 34.7% - 65.3% - 100.0% - - - - - - - - 77.0% 23.0% 

1977 31.6% - 68.4% - 100.0% - - - - - - - - 76.2% 23.8% 

1978 32.1% - 67.9% - 99.3% 0.7% - - - - - - - 70.9% 29.1% 

1979 35.1% 2.1% 62.8% - 96.0% 4.0% - - - - - 3.3 - 81.9% 18.1% 

1980 53.0% 24.5% 22.4% - 89.2% 10.8% - - - - - 3.5 1.4% 73.6% 25.0% 

1981 51.6% 31.1% 17.3% - 86.1% 13.9% - - - - - 3.6 1.9% 78.0% 20.1% 

1982 45.9% 33.4% 20.7% - 83.8% 16.2% - - - - - 3.7 1.7% 78.1% 20.2% 

1983 46.3% 36.0% 17.4% - 81.6% 18.4% - - - - - 3.9 1.4% 72.5% 26.1% 

1984 42.5% 34.6% 22.9% - 78.6% 21.4% - - - - - 3.9 5.0% 63.5% 31.5% 

1985 37.6% 41.1% 21.2% - 78.6% 21.4% - - - - - 3.8 7.3% 61.4% 31.3% 

1986 43.0% 41.5% 15.5% - 69.1% 30.9% - - - - - 4.0 5.9% 63.4% 30.7% 

1987 40.5% 43.8% 15.7% - 70.1% 29.9% - - - - - 4.0 7.6% 60.2% 32.2% 

1988 35.8% 52.5% 11.7% - 68.4% 31.6% - - - - - 4.1 9.2% 56.7% 34.1% 

1989 32.8% 56.4% 10.8% - 70.3% 29.7% - - - - - 4.1 10.1% 57.1% 32.8% 

1990 28.1% 67.5% 4.4% - 74.1% 25.9% - - - - - 4.1 15.8% 52.4% 31.8% 

1991 31.5% 66.8% 1.7% - 69.0% 31.0% - - - - - 4.2 10.3% 52.3% 37.3% 

1992 27.5% 71.3% 1.2% - 74.6% 25.4% - - - - - 4.2 14.5% 52.1% 33.4% 

1993 24.7% 74.2% 1.1% - 76.0% 24.0% - - - - - 4.2 16.8% 50.6% 32.7% 

1994 23.7% 75.3% 1.0% - 76.7% 23.3% - - - - - 4.2 13.8% 47.0% 39.2% 

1995 20.7% 78.5% 0.9% - 79.6% 20.4% - - - - - 4.2 18.4% 39.3% 42.3% 

1996 15.6% 83.4% 1.0% - 84.4% 15.6% - - - - - 4.1 20.9% 39.8% 39.2% 

1997 14.1% 85.8% 0.1% - 79.9% 20.1% - - - - - 4.2 14.2% 40.6% 45.2% 

1998 13.6% 85.8% 0.6% - 81.1% 18.9% - - - - - 4.2 19.3% 35.5% 45.1% 

1999 9.2% 90.4% 0.4% - 85.8% 14.2% - - - - - 4.1 17.5% 34.4% 48.1% 

2000 8.2% 91.5% 0.3% - 87.3% 12.7% - - - - - 4.1 20.0% 33.8% 46.3% 

2001 6.3% 93.4% 0.3% - 84.0% 16.0% - - - - - 4.2 16.3% 34.8% 48.8% 

2002 4.7% 94.9% 0.3% 0.0% 76.7% 23.3% - - - - 0.0% 4.2 15.4% 33.1% 51.6% 

2003 4.6% 94.4% 0.3% 0.6% 71.1% 28.2% - - - - 0.6% 4.3 15.4% 34.1% 50.4% 

2004 3.5% 95.6% 0.3% 0.6% 63.2% 35.5% 0.8% - - - 0.6% 4.4 12.5% 31.0% 56.5% 

2005 2.9% 95.3% - 1.8% 54.3% 41.9% 2.1% - - - 1.8% 4.5 20.1% 27.7% 52.2% 

2006 3.3% 93.7% - 3.1% 48.0% 44.3% 3.8% 0.8% - - 3.1% 4.6 18.9% 28.0% 53.1% 

2007 2.6% 93.8% - 3.7% 45.8% 38.0% 11.5% 1.0% - - 3.7% 4.7 16.1% 28.4% 55.5% 

2008 2.2% 94.1% - 3.6% 37.9% 37.4% 19.9% 1.2% - - 3.6% 4.8 18.4% 24.8% 56.8% 

2009 2.0% 92.0% - 6.0% 23.5% 33.7% 35.1% 1.6% - - 6.0% 5.2 21.0% 20.5% 58.4% 

2010 1.8% 91.9% 0.4% 5.9% 16.4% 29.1% 46.7% 1.9% - - 5.9% 5.4 20.9% 18.0% 61.0% 

2011 1.3% 91.4% 0.0% 7.3% 11.9% 26.5% 50.5% 1.9% 1.9% - 7.3% 5.5 17.7% 17.3% 65.0% 

2012 1.4% 92.4% - 6.2% 10.3% 24.4% 54.6% 2.2% 2.2% - 6.2% 5.6 20.9% 14.8% 64.4% 

2013 1.1% 90.2% - 8.7% 4.7% 20.2% 60.4% 2.0% 4.0% - 8.7% 5.8 17.9% 14.4% 67.7% 

2014 1.1% 90.5% - 8.4% 1.1% 11.8% 64.8% 2.2% 9.8% 1.8% 8.4% 6.1 16.6% 16.2% 67.2% 

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Technology Adoption Rates 

Technology in new vehicles is continually changing and evolving. Innovative new technologies are regularly being 

introduced, replacing older and less effective technologies. This continuous cycle of improvement and reinvention has been the driving force behind nearly all of the trends examined in this report. Section 5 detailed 

many specific technological changes that have taken place since 1975. This section provides a detailed look at the 

rate at which the automotive industry as a whole has adopted new technology, the rate at which individual 

manufacturers have adopted technology, and the differences between the overall industry and manufacturer 

adoption rates. In recent years, several other studies have examined technology penetration trends in the 

automotive industry, notably researchers at Argonne National Laboratory (Plotkin, et al. 2013), MIT's Sloan 

Automotive Laboratory (Zoepf and Heywood 2013), EPA, and The University of Michigan (DeCicco 2010). 

It is important to note that this section focuses on “successful” technologies, those technologies that have 

achieved widespread use by multiple manufacturers and, in some cases, by all or nearly all manufacturers. This 

section does not look at “unsuccessful” technologies which never achieved widespread use. One consequence of 

a competitive and technology-driven enterprise like the automobile industry is that there will certainly be a 

number of unsuccessful technologies. A technology may prove to be unsuccessful for one or more of many 

reasons: cost, effectiveness, tradeoffs with other vehicle attributes, consumer acceptance, or, in some cases, the 

technology may be successful for a time but later displaced by a newer and better technology. The Trends 

database does not provide data on why technologies fail, but it does provide data on how quickly successful 

technologies can penetrate the marketplace, and the latter is the subject of this section. 

One inherent limitation in using the Trends database to track the introduction of new technologies is that there is 

often a lag between the introduction of a new technology and the modifications to the formal EPA vehicle 

compliance information system that are necessary to ensure proper tracking of the new technology. Accordingly, 

for many of the technologies discussed in this section, the Trends database did not begin tracking production 

share data until after the technologies had achieved some limited market share. For example, as shown in Tables 

5.2.2 and 5.2.3, Trends did not begin to track multi-valve engine data until MY 1986 for cars and MY 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 Trends until MY 1996 for cars and MY 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, well 

before being tracked by Trends. 

Accordingly, this section best addresses the question, “How quickly have successful technologies moved from 

limited use to widespread use,” for both industry-wide and for individual manufacturers, and does not address 

other important issues such as how long it takes for technologies to be developed or to achieve limited market 

share, or why many technologies fail to ever achieve widespread use. 

83 
 

 

 

 

 

 

 

 

 

 

 

 

A. INDUSTRY-WIDE TECHNOLOGY ADOPTION 

SINCE 1975 

Automotive technology has continually evolved since 1975, resulting in vehicles that have 

better fuel economy, more power, and more content. One of the most notable examples of 

this continual improvement is the evolution of fuel delivery in gasoline engines. Carburetors, 

the dominant fuel delivery system in the late 1970s and early 1980s, were replaced by port fuel 

injection systems, which in turn are being replaced by direct injection systems. This trend, and 

the substantial impact on engine fuel economy and performance, is explored in Figures 5.4 

and 5.5. 

Figure 6.1 has been published in this report for many years, and has been widely cited in the 

literature. This figure shows industry-wide adoption rates for five mature technologies in 

passenger cars that have achieved wide adoption across the entire industry. Adoption rates for 

these technologies in trucks are similar, with the exception of front wheel drive. To provide a 

common scale, the adoption rates are plotted in terms of the number of years after the 

technology was first introduced into the market (in some cases very limited use of the 

technology may have occurred before being tracked in this report). The five technologies 

included in Figure 6.1 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, and lockup transmissions. For each of these technologies, it 

took at least a decade to attain an industry wide production fraction of 60% after first use, and 

another five to ten years to reach maximum penetration. 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. Figure 6.1 

shows that it has historically taken about 20 years for the industry to widely adopt a new 

technology after it was first introduced into the marketplace. 

84 
 

 

 

 

Figure 6.1 

Industry-Wide Car Technology Penetration after First Significant Use 

Fuel Injection 

Multi-Valve 

Lockup 

Front 

Wheel 

Drive 

0% 

25% 

50% 

75% 

100% 

Production Share 

0 10 20 30 40 

Variable Valve Timing 

Years after First Use 

B. TECHNOLOGY ADOPTION BY MANUFACTURERS 

The rate at which the overall industry adopts technology, as shown in Figure 6.1, is actually 

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 6.1 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 6.2 begins to disaggregate the industry-wide trends shown in Figure 6.1 to examine how 

individual manufacturers have adopted new technologies. The first four technologies shown in 

Figure 6.2, which are also shown in Figure 6.1, have reached (or are near) full market 

penetration for all manufacturers. Also included in Figure 6.2 are three additional 

technologies that are quickly increasing penetration in new vehicle production, and are 

projected to be installed on at least 15% of all MY 2014 vehicles. These technologies are 

advanced transmissions (defined here as transmissions with 6 or more speeds and CVTs), 

gasoline direct injection (GDI) systems, and turbocharged engines. Figure 6.2 shows the 

percent penetration of each technology over time for the industry as a whole, and individually 

85 
 

 

 

 

 

 

 

 

for the top seven manufacturers by sales. Figure 6.2 focuses on the length of time each 

manufacturer required to move from initial introduction to 80% penetration for each 

technology. 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. 

The technologies shown in Figure 6.2 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 variable valve timing (VVT), for example, shows that several manufactures were 

able to adopt the technology much faster than the overall industry rate might suggest. As 

shown in Figure 6.1, it took a little over 20 years for VVT to reach 80% penetration across the 

industry as a whole. However, Figure 6.2 shows that several individual manufacturers were 

able to implement at least 80% VVT in significantly less time than the overall industry. 

Therefore, it was not the rate of technology adoption alone, but rather the staggered 

implementation time frames 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 (see Figure 6.1) than 

technologies like VVT. One important driver for adoption of fuel injection was increasingly 

stringent emissions standards. Advanced transmissions, and turbocharged engines, have been 

available in small numbers for some time, but have very rapidly increased market penetration 

in recent years. Turbocharged engines and GDI systems are only recently beginning to reach 

significant parts of the market, and while both technologies are showing variation in adoption 

between manufacturers, it is too early to tell whether, and how quickly, they will ultimately be 

adopted industry-wide. 

A different way to look at technology adoption patterns is to look at the maximum rate of 

change that manufacturers have been able to achieve for each technology. Figure 6.3 uses this 

approach to look at technology adoption for the same manufacturers and technologies 

examined in Figure 6.2. For each technology and manufacturer, Figure 6.3 shows the 

maximum change in technology penetration that each manufacturer achieved over any 3-year 

and 5-year period. 

86 
 

Figure 6.2 

Manufacturer Specific Technology Adoption over Time for Key Technologies* 

All Manufacturers Hyundai 

Nissan 

Chrysler−Fiat 

Honda 

Ford 

Toyota 

GM 

Fuel Injection 

1980 1990 2000 2010 

Ford
 GM
 Toyota
 Chrysler−Fiat
 Lockup Honda 

Nissan 

Hyundai All Manufacturers

1980 1990 2000 2010 

All Manufacturers Hyundai 

Nissan 

Chrysler−Fiat 

Honda 

Ford 

Toyota 

GM 

Multi-Valve 

Manufacturer

Ford 

GM 

Toyota Chrysler−Fiat 

Honda 

Nissan 

Hyundai All Manufacturers

Ford 

GM 

Toyota Chrysler−Fiat 

Honda 

Nissan 

Hyundai All Manufacturers

Ford 

GM 

Toyota Chrysler−Fiat 

Honda 

Nissan 

Hyundai All Manufacturers

Ford 

GM 

Toyota Chrysler−Fiat 

Honda 

Nissan 

Hyundai All Manufacturers

1980 1990 2000 2010 

Variable Valve 

Timing 

1980 1990 2000 2010 

Advanced 

Transmissions 

1980 1990 2000 2010 

Gasoline Direct 

Injection 

1980 1990 2000 2010 

Turbocharged 

1980 1990 2000 2010 

Model Year
 

Percent of Production
 20% to 25% 

0% to 5% 

10% to 15% 

25% to 50% 

5% to 10% 

15% to 20% 

{

75% to 80% {

50% to 75% 

{

80% to 100% {

* 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 multi-valve engines in 1986, so 

this figure does not illustrate Honda’s increase prior to 1986. 

87 
 

 

 

 

 

 

 

 

 

There are many examples of manufacturers that were able to apply new technology to a large 

percentage of their new vehicles in only 3 to 5 years. For example, each of the manufacturers 

was able to increase the percentage of their new vehicles with fuel injection systems by over 

50% in 5 years, and three manufacturers were able to increase the percentage of their new 

vehicles with VVT by more than 85% in that time. For VVT, all of the manufacturers 

achieved close to or above a 70% penetration change in a 5-year period, but the industry as a 

whole only achieved a 40% change over any 5 years. This data reinforces the conclusion that 

the staggered timing of VVT adoption by individual manufacturers resulted in an overall 

industry adoption period that is longer than actually required by many (if not most) individual 

manufacturers. 

One important note for Figure 6.3 is that, in some cases, individual manufacturers were 

already at high rates of adoption of some technologies before Trends started collecting data for 

that technology (for example, Honda was using multi-valve engines throughout its fleet when 

EPA starting monitoring multi-valve data in the mid-1980s). Data for “rates of increase” in 

such cases are artificially low. 

Figure 6.4 takes a more detailed look at the introduction of VVT by individual manufacturers 

by combining aspects of both Figure 6.2 and Figure 6.3. For each manufacturer, Figure 6.4 

shows the actual percent penetration of VVT over time (solid red line) versus the average for 

all manufacturers (dotted grey line), and compared to the maximum penetration by any 

manufacturer (solid grey line) over time. Figure 6.4 also shows when the largest increase in 

VVT penetration over any 1, 3, and 5 year period occurred as green, orange, and yellow boxes. 

VVT was first tracked in this report for cars in MY 1990 and for trucks in MY 2000. Between 

MY 1990 and MY 2000, there may be a small number of trucks with VVT that are not 

accounted for in the data. However, the first trucks with VVT produced in larger volumes 

(greater than 50,000 vehicles) were produced in MY 1999 and MY 2000, so the discrepancy is 

not enough to noticeably alter the trends in the previous figures. 

88 
89 

Figure 6.3 

Maximum Three- and Five-Year Adoption for Key Technologies 

* 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 multi-valve engines in 1986, so this figure does not illustrate Honda’s increase prior to 1986.

 

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

Advanced

Transmission

Fuel Injection

Lockup

Multi-Valve

Variable Valve

Timing

Gasoline Direct

Injection

Turbocharged

0% 25% 50% 75% 100% 0% 25% 50% 75% 100%

Fastest Multi-Year Penetration Increase

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

All Manufacturers Hyundai

Nissan

Chrysler−Fiat

Honda

Ford

Toyota

GM

3-Year Increase 5-Year Increase

Manufacturer

* *
 

 

 

 

 

 

 

 

Figure 6.4 

VVT Adoption Details by Manufacturer 

Chrysler-Fiat GM 

Honda Hyundai Nissan 

0% 

25% 

50% 

75% 

100% 

199019952000200520102015 

Percent of vehicles with VVT

Toyota 

Ford 

0% 

25% 

50% 

75% 

100% 

0% 

25% 

50% 

75% 

100% 

Best 1-year increase 

Best 3-year increase 

Best 5-year increase 

Highest 

Fleet Average 

Manufacturer 

All Manufacturers 

199019952000200520102015 

199019952000200520102015 

Model Year 

As shown in Figure 6.2, each manufacturer clearly followed a unique trajectory to adopt VVT. 

It took over 20 years for nearly all new vehicles to adopt VVT; however it is also very clear that 

individual manufacturers were able to adopt VVT across their own vehicle offerings much 

faster. All of the manufacturers shown in Figure 6.4 were able to adopt VVT across the vast 

majority of their new vehicle offerings in under 15 years, and many accomplished that feat in 

under 10 years. As indicated by the yellow rectangles in Figure 6.4, several manufacturers 

increased their penetration rates of VVT by 75% or more over a 5-year period. It is also 

important to note that every manufacturer shown was able to adopt VVT into new vehicles at 

a rate faster than the overall industry-wide data would imply. As noted earlier, the industry 

average represents both the rate that manufacturers adopted VVT and the effect of 

manufacturers adopting the technology at different times. Accordingly, the industry average 

shown in Figure 6.1 and Figure 6.4 does not represent the average pace at which individual 

manufacturers adopted VVT, which is considerably faster. 

90 
 

 

 

 

 

Figures 6.2 through 6.4 examine manufacturer specific technology adoption in different ways, 

but all three figures clearly support the conclusion that some manufacturers have been able to 

adopt technology much faster than industry-wide data suggest, and that there is significant 

variation in how individual manufacturers have adopted technology. 

C. TECHNOLOGY ADOPTION IN THE LAST FIVE YEARS 

Over the last five years, engines and transmissions have continued to evolve and adopt new 

technologies. Figure 6.5 shows the penetration of several key technologies in MY 2009 and the 

projected penetration for each technology in MY 2014 vehicles. Over that five-year span, VVT 

is projected to increase market share by 26%, GDI by over 30%, and 6 speed transmissions by 

over 35% across the entire industry. These are large changes taking place over a relatively short 

time. As discussed in the previous section, there are manufacturer specific changes in this 

timeframe that are even more impressive. 

Figure 6.5 

Five Year Change in Light Duty Vehicle Technology Penetration Share 

0% 

25% 

50% 

75% 

100% 

Production Share 

MY 2009 

MY 2014 

VVT Multi- GDI Turbo Cyl. Non- Hybrid Diesel Six Seven CVT 

Valve Deact. Hybrid Speed Speed+ 

Stop/Start 

There are many factors outside the scope of this report that influence the rate and timing of 

when technology is adopted by individual manufactures (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 evaluating industry-wide trends. As the data in this 

section suggest, adoption by individual manufacturers is generally more rapid than has 

previously been reported for the overall industry, and it is clear that the penetration of 

important technologies has grown significantly over the last 5 years. 

91 
 

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Alternative Fuel Vehicles 

This section addresses original equipment manufacturer (OEM)6 vehicles that are dedicated to, or are designed 

and expected to frequently operate on, alternative fuels such as electricity and natural gas. Ethanol flexible fuel 

vehicles are widely available, but the great majority of these vehicles are operated primarily on gasoline and 

therefore are not included in this section. OEM vehicles that operate predominantly on other alternative fuels, 

including hydrogen, methanol, propane, etc., will be included in future reports if they become generally available 

to the public. 

Increasing interest in alternative fuel vehicles is being driven by several factors: sustained high oil prices, concerns 

about future oil supplies and greenhouse gas emissions, and economic and national security issues associated 

with oil imports. This is an emerging area, with several new OEM alternative fuel vehicle models introduced in MY 

2014 and more planned for subsequent model years. Often, alternative fuel vehicle models are initially 

introduced in selected areas of the country, but many alternative fuel vehicle models are now available on a 

nationwide basis. The main focus of this section will be preliminary data on MY 2014 vehicles, and a new 

discussion of the impact of alternative fuel vehicles on overall new MY 2013 fuel economy and CO2 emissions 

values. 

Fuel economy and CO2 emissions data in this section reflect values from the EPA/DOT Fuel Economy and 

Environment Labels. These values are similar to the methodology used for the adjusted fuel economy and CO2 

values in Sections 2-6 of this report, except the analysis in this section, unless otherwise noted, uses the 55% 

city/45% highway weighting reflected in new vehicle labels. 

A. METHODOLOGY 

The Trends analyses provided in Sections 2-6 include vehicle data from 1975 to the present 

only for vehicles that are dedicated to or are expected to operate primarily on petroleum fuels, 

i.e., gasoline and diesel fuel. The primary reason for this is simply that the small number of 

OEM vehicles that predominantly use alternative fuels would have a very small impact on the 

analyses in Sections 2-6. In contrast, this section focuses on vehicles that are designed and 

expected to operate on other fuels, namely electric vehicles (EVs), plug-in hybrid vehicles 

(PHEVs), and compressed natural gas (CNG) vehicles. 

Vehicles that can operate on both a petroleum-based fuel and an alternative fuel pose an 

analytical challenge. There are currently a large number of “flexible fuel vehicles” (FFVs) in the 

market that are capable of using either gasoline or E85 (a mixture of 85% ethanol and 15% 

gasoline, by volume), or any blend in between. Historically, these vehicles have operated 

predominantly on gasoline (and ethanol-gasoline blends with low levels of ethanol).7 EPA 

believes that there are many reasons why most consumers use gasoline in their FFVs: limited 

E85 fuel availability, greater vehicle range on gasoline, and E85 fuel pricing such that the fuel 

cost per mile is typically cheaper on gasoline. Accordingly, this report continues to assume that 

6 This section, like the rest of the report, focuses only on OEM produced vehicles. There are aftermarket converters who modify OEM
 

gasoline vehicles to operate on alternative fuels, but those vehicles are not accounted for in this section.
 7 Based on data from the Energy Information Administration, EPA projects that FFVs were fueled with E85 less than 1 percent of the time in
 

2008; see 75 Federal Register 14762 (March 26, 2010).
 

92 
 

 

 

 

 

 

 

ethanol FFVs operate primarily on gasoline, with the analyses in Sections 2-6 including data 

from FFV operation on gasoline and excluding data from FFV operation on E85. If, in the 

future, FFVs operate more often on E85 fuel, EPA will consider adding FFVs to this 

alternative fuel vehicle analysis. 

Two other technologies that can use both a petroleum-based fuel and an alternative fuel are 

plug-in hybrid electric vehicles (PHEVs) and dual-fuel compressed natural gas (DF-CNG) 

vehicles. While it is almost certain that PHEVs and DF-CNG vehicles will use at least some 

gasoline, there are two factors that strongly suggest that most owners of these vehicles will seek 

to use the alternative fuel as much as possible: 1) they have paid a substantial premium to buy 

a vehicle that can use the alternative fuel, and 2) the alternative fuel is considerably cheaper 

than gasoline, and provides an opportunity for the vehicle owner to recover the higher upfront 

cost of the vehicle through ongoing fuel savings. Because we expect PHEVs and DF-CNG 

vehicles to operate frequently on alternative fuels, they are included in this section and not in 

the primary Trends analyses in Sections 2-6. 

With respect to other vehicles that may be introduced in the future that can operate on both 

petroleum and alternative fuels, EPA will determine on a case-by-case basis whether it is more 

appropriate to include them in the primary petroleum fuel analyses or in this separate 

alternative fuel vehicle section. 

The number of alternative fuel vehicles produced is still too small (less than 1.0 percent of MY 

2013 production) to have a large impact on the overall technology, CO2 emissions, and fuel 

economy trends; however, many additional alternative fuel vehicle models are expected to 

enter the market over the next few years.8 At some point in the future, as the sales of 

alternative fuel vehicles continue to increase, EPA will consider merging alternative fuel 

vehicle data into the primary Trends analysis. 

Another issue with comparing the fuel economy and CO2 emissions of conventional vehicles 

with alternative fuel vehicles is choice of metrics. For example, choice of an energy metric is 

complicated by very different feedstocks and production processes for various fuels. This 

section uses the energy metric of mpge (miles per gallon of gasoline-equivalent, i.e., the miles 

that an alternative fuel vehicle can travel on an amount of alternative fuel with the same 

energy content as a gallon of gasoline) in order to be consistent with its use on the EPA/DOT 

Fuel Economy and Environment Label. But, there are other energy metric options that could 

be considered, such as 1) mpge plus net fuel life-cycle energy, which would also reflect 

differences in upstream energy consumption in producing the alternative fuel relative to 

gasoline-from-oil; and 2) miles per gallon of petroleum, which would only count petroleum use 

and not other forms of energy. Compared to mpge, using the mpge plus net fuel life-cycle 

energy metric would generally result in lower numerical fuel economy values, and using the 

miles per gallon of petroleum metric would yield higher fuel economy values. For CO2 

8 For example, see list of potential future EVs and PHEVs at fueleconomy.gov/feg/evnews.shtml. 

93 
 

 

 

 

 

 

 

 

 

 

 

emissions metrics, this section primarily uses tailpipe CO2 emissions, but also presents some 

upstream CO2 emissions values as well. 

Except where noted, this section (and sections 8 and 9) reports combined fuel economy and 

CO2 values based on the 55% city/45% highway weighting used for the Fuel Economy and 

Environment Labels and for GHG emissions and fuel economy standards compliance, and 

not on the 43% city/57% highway weighting used for adjusted fuel economy values 

throughout sections 2-6 of this report. 

B. HISTORICAL TRENDS 

Alternative fuel vehicles have a long history in the U.S. automotive market. Electric vehicles, 

for example, were available at least as far back as the early 1900s. Gasoline and diesel vehicles, 

however, have long dominated new light vehicles sales. Over the course of this report, OEM 

vehicles that operate frequently on alternative fuels have been available only in small 

numbers,

9 though those limited production vehicles have in some cases created significant 

consumer and media interest. Since MY 2011, renewed interest in alternative fuel vehicles has 

resulted in many new vehicle launches, and growing sales. 

In the mid-1990s, the state of California passed legislation creating the Zero Emission Vehicle 

(ZEV) mandate. In response to the ZEV mandate, OEMs began to produce limited numbers of 

electric vehicles. Most of these vehicles were leased, rather than sold, in the state of California. 

The majority of these electric vehicles were small passenger cars, SUVs, or pickup trucks, 

including the GM EV1, the Toyota RAV4 EV, and the Ford Ranger EV. 

Dedicated CNG vehicles have been available in limited numbers for the last twenty years, most 

commonly during and after periods of rising gasoline prices. CNG vehicles have spanned a 

wider range of vehicles, from work trucks and vans to the Honda Civic Natural Gas, which has 

been available in select markets since MY 1998. 

In MY 2000, five electric vehicles (EVs), seven dedicated CNG vehicles, and one DF-CNG 

vehicle were available in the U.S. market. Chrysler-Fiat, Ford, GM, Honda, Nissan, and 

Toyota all produced at least one alternative fuel vehicle in MY 2000, with total production of 

about 3,500 vehicles. Most of these vehicles were produced in very small volumes and only for 

a few model years. However, by MY 2006, only one alternative fuel vehicle was available, the 

Honda Civic Natural Gas. The Tesla Roadster, a dedicated electric vehicle, was introduced 

with limited production in MY 2008. From MY 2008 through MY 2010, the Civic Natural 

Gas and the Tesla Roadster were the only two alternative fuel vehicles produced by OEMs. 

From MY 1995 (which is as far back as reliable alternative fuel vehicle data was available for 

this report) to MY 2010, over 99.9% of all new OEM vehicles were petroleum fueled, with 

annual production of alternative fuel vehicles less than 3,500 per year. 

9 Millions of ethanol FFVs have been sold in recent years, but these vehicles have operated primarily on gasoline. 

94 
 

 

 

 

 

 

 

 

 

 

 

The market for alternative fuel vehicles began a dramatic change in MY 2011 with several new 

vehicles, including the high profile launches of the Chevrolet Volt PHEV and the Nissan Leaf 

EV. The Volt and Leaf had combined production of nearly 13,000 vehicles in MY 2011, so 

production of these two vehicles alone tripled the total number of alternative fuel vehicles 

produced in MY 2011 relative to any model year since at least 1995. Production of the Volt 

and Leaf has continued to climb through MY 2013, with over 55,000 combined sales in MY 

2013. In MY 2013, there were eleven EVs available in the market, and four PHEVs, with more 

new models expected in MY 2014 and beyond. The Honda Civic natural gas model averaged 

production of under 1,000 vehicles per year from MY 1998-2011, with a production record in 

MY 2012 of over 3,000 vehicles. When it was initially introduced, the Honda Civic Natural 

Gas was available only to fleet customers, but it subsequently became available for retail in 

California, New York, Utah, and Oklahoma, and is now available in many states across the 

country. OEMs other than Honda have not directly offered CNG vehicles, and the Civic 

Natural Gas remains the only OEM light-duty natural gas vehicle on the market. 

The combined production of alternative fueled vehicles has increased from under 1,200 in 

MY 2010, to nearly 105,000 in MY 2013. While alternative fueled vehicles still represent a 

very limited portion of overall new vehicle production (0.7% of overall light-duty vehicle 

production in MY 2013), this increase by a factor of about 100 in three years is both notable 

and significant. Figure 7.1 shows the historical sales of EVs, PHEVs, and dedicated CNG 

vehicles since 1995 (we do not have reliable data on alternative fuel vehicles back to 1975). 

Figure 7.1 

Historical Production of EVs, PHEVs, and Dedicated CNG Vehicles, MY 1995 - 2013 

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

110 

1995 2000 2005 2010 2015 

Production (000)

CNG 

EV 

PHEV 

Model Year 

Consistent with the rest of this report, Figure 7.1 was largely compiled from manufacturer 

CAFE submissions. Some of the historical sales data was supplemented with data from Ward’s 

and other publically available production data. Figure 7.1 includes dedicated CNG vehicles, 

95 
 

 

 

 

 

 

 

 

 

 

 

 

 

but not dual fuel CNG vehicles as sales data were not available for dual fuel vehicles. The data 

only includes offerings from OEMs, and does not include data on vehicles converted to 

alternative fuels in the aftermarket. 

C. MY 2014 VEHICLES 

Since sales of alternative fuel vehicles have historically been limited, this section of the report 

will focus on currently available alternative fuel vehicles produced by OEMs and introduce 

several metrics that are important for alternative fuel vehicles, instead of analyzing aggregated 

new vehicle data. Table 7.1 shows the alternative fuel vehicles available from OEMs in MY 

2014, as well as the powertrain type of each vehicle, inertia weight class (IWT),

10 and 

footprint. These vehicles constitute a wide array of vehicle design, size, and function. 

Table 7.1 

MY 2014 Alternative Fuel Vehicle Classification and Size 11 

Fuel or Car or IWT Footprint 

Make Model Powertrain Truck (lbs) (sq ft) 

Chevrolet Spark EV Car 3000 36.1 

BMW i3 EV Car 3000 43.5 

BYD e6 EV Car 5500 47.4 

Fiat 500e EV Car 3000 34.9 

Ford Focus EV Car 4000 44.0 

Honda Fit EV Car 3500 39.7 

Mercedes-Benz B-class EV Car 4000 45.0 

Mitsubishi i EV Car 2750 38.4 

Nissan Leaf EV Car 3500 44.7 

Smart Fortwo EV Car 2250 26.8 

Tesla Model S (60kW-hr) EV Car 4500 53.5 

Tesla Model S (85kW-hr) EV Car 4500 53.5 

Toyota RAV4 EV Car 4000 44.6 

BMW i3 REX PHEV Car 3500 43.5 

BMW i8 PHEV Car 3500 48.5 

Cadillac ELR PHEV Car 4000 45.9 

Chevrolet Volt PHEV Car 4000 45.3 

Ford C-MAX PHEV Car 4000 43.8 

Ford Fusion PHEV Car 4000 48.4 

Honda Accord PHEV Car 4000 47.5 

McLaren P1 PHEV Car 3500 46.9 

Porsche Panamera S PHEV Car 5000 52.2 

Toyota Prius PHEV Car 3500 44.2 

Honda Civic CNG Car 3000 43.5 

10 Each inertia weight class represents a range of loaded vehicle weights, or vehicle curb weights plus 300 pounds. Vehicle inertia weight 

classes are in 250-pound increments for inertia weight classes that are less than 3000 pounds, while inertia weight classes over 3000 

pounds are divided into 500-pound increments. 11 There are several other non-petroleum fueled vehicles that have been in limited lease and/or demonstration programs, including 

hydrogen fuel cell vehicles such as the Honda FCX Clarity and Hyundai Tucson Fuel Cell. However, these vehicles have not been available to 

the general public at large and are therefore not discussed in this section. 

96 
 

 

 

 

 

 

 

 

As shown in Table 7.1, there are twelve EVs available in MY 2014 (the two Tesla S variants are 

considered one model, as explained in Section 8), ten PHEVs, and one dedicated CNG 

vehicle. The footprint of the largest vehicle, the Tesla S, is double that of the smallest vehicle, 

which is the Smart Fortwo. The weight of these vehicles also significantly varies, from an IWT 

of 2250 to 5000. 

This report has not previously tracked or analyzed data on the range of vehicles using 

petroleum fuels because gasoline and diesel vehicles can generally travel at least 300 miles 

without refueling, and gasoline and diesel fuel stations are common and well distributed 

across the United States (although there are some rural areas where range may in fact be an 

important consideration). Most alternative fuel vehicles are expected to have lower vehicle 

range than gasoline and diesel vehicles, when operated on the alternative fuel, and all 

alternative fuel vehicles are likely to have more limited public refueling infrastructure. Range is 

of particular concern with electric vehicles, as today’s battery technology limits the range of 

EVs to considerably less than that of comparable petroleum-fueled vehicles. The availability of 

dedicated EV charging stations is also currently limited, especially for stations powerful 

enough to be capable of “fast” charging.

12 For each of the vehicles listed in Table 7.1, Table 

7.2 shows the label driving range for alternative fuel vehicles when operating on the alternative 

fuel, total electricity plus gasoline range for PHEVs, and introduces the concept of a utility 

factor for PHEVs (explained below). 

12 While dedicated EV charging stations are currently limited, electricity is available in nearly all but the most remote parts of the country. 

EVs can generally be recharged from a standard 110v outlet, though charging will be slower than at a dedicated 220v charging station. 

97 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 7.2 

MY 2014 Alternative Fuel Vehicle Powertrain and Range 

Alternative Total 

Fuel or Fuel Range Range Utility 

Make Model Powertrain (miles)* (miles) Factor 

Chevrolet Spark EV 82 82 N/A 

BMW i3 EV 81 81 N/A 

BYD e6 EV 127 127 N/A 

Fiat 500e EV 87 87 N/A 

Ford Focus EV 76 76 N/A 

Honda Fit EV 82 82 N/A 

Mercedes-Benz B-class EV 87 87 N/A 

Mitsubishi i EV 62 62 N/A 

Nissan Leaf EV 84 84 N/A 

Smart Fortwo EV 68 68 N/A 

Tesla Model S (60kW-hr) EV 208 208 N/A 

Tesla Model S (85kW-hr) EV 265 265 N/A 

Toyota RAV4 EV 103 103 N/A 

BMW i3 REX PHEV 72 150 0.83 

BMW i8 PHEV 15 330 0.37 

Cadillac ELR PHEV 37 340 0.65 

Chevrolet Volt PHEV 38 380 0.66 

Ford C-MAX PHEV 20 550 0.45 

Ford Fusion PHEV 20 550 0.45 

Honda Accord PHEV 13 570 0.33 

McLaren P1 PHEV 19 300 0.43 

Porsche Panamera S PHEV 16 540 0.39 

Toyota Prius PHEV 11 540 0.29 

Honda Civic CNG 192 192 N/A 

* Many PHEVs are capable of operating in blended mode and may use some gasoline to 

achieve the given alternative fuel range. 

PHEVs blend EV technology with more familiar powertrain technology from petroleum-fueled 

vehicles. Current PHEVs feature both an electric drive system designed to be charged from an 

electricity source external to the vehicle (like an EV), and a gasoline internal combustion 

engine. There are generally three ways that a PHEV can operate: 

1.	 Charge depleting electric only mode – In electric only mode the vehicle operates like 

an EV, using only energy stored in the battery to propel the vehicle. 

2.	 Charge depleting blended mode – In blended mode the vehicle uses both energy 

stored in the battery and energy from the gasoline tank to propel the vehicle. 

Depending on the vehicle design and driving conditions, blended operation can 

include substantial all-electric driving. 

3.	 Charge sustaining mode – In charge sustaining mode, the PHEV has exhausted the 

external energy from the electric grid that is stored in the battery and relies on the 

gasoline internal combustion engine. In charge sustaining mode, the vehicle will 

operate much like a traditional hybrid. 

98 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The presence of both electric drive and an internal combustion engine results in a complex 

system that can be used in many different combinations, and manufacturers are each choosing 

to operate PHEV systems in different ways. This complicates direct comparisons among PHEV 

models in this report. For each MY 2014 PHEV, Table 7.2 shows the estimated range on 

alternative fuel and estimated total range. For PHEVs like the Chevrolet Volt, which cannot 

operate in blended mode, the alternative fuel range represents the estimated range operating 

in electric only mode. However, for PHEVs that operate in a blended mode, the alternative 

fuel range represents the estimated range of the vehicle operating in either electric only or 

blended mode, due to the design of the vehicle. For example, the Prius uses electricity stored 

in its battery and a small amount of gasoline to achieve an alternative fuel range of 11 miles. 

The C-Max and Fusion PHEVs did not use any gasoline to achieve an alternative fuel range of 

20 miles on EPA test cycles; however, certain driving conditions (e.g., more aggressive 

accelerations, higher speeds, and air conditioning or heater operation) would likely cause these 

vehicles to operate in a blended mode instead of an all-electric mode. Table 7.2 also introduces 

the concept of a utility factor. The utility factor is directly related to the electric range for 

PHEVs, and is a projection, on average, of the percentage of miles that will be driven using 

electricity (in electric only and blended modes) by an average driver. 

The one vehicle that operates on CNG has a traditional internal combustion engine. Many 

internal combustion engines designed to run on CNG are based on gasoline engines, with 

upgraded fuel systems and tanks designed specifically for natural gas. 

Table 7.3 shows five energy-related metrics for the MY 2014 alternative fuel vehicles (no entry 

is shown if the metric is not applicable to that vehicle technology). These data are generally 

included on the EPA/NHTSA Fuel Economy and Environment labels beginning in MY 2013. 

Comparing the energy or fuel efficiency performance from alternative fuel vehicles raises 

complex issues of how to compare different fuels. For example, consumers and OEMs are 

familiar and comfortable with evaluating gasoline and diesel vehicle fuel economy in terms of 

miles per gallon, and it is the primary efficiency metric in this report. To enable this 

comparison for alternative fuel vehicles, the fuel efficiency of vehicles operating on CNG and 

electricity are evaluated in terms of miles per gallon of gasoline equivalent (an energy metric 

described in more detail below). 

The fourth column in Table 7.3 gives electricity consumption rates for EVs and PHEVs. The 

units for electricity consumption are kilowatt-hours per 100 miles (kW-hrs/100 miles). As 

shown on the vehicle label, the electricity consumption rate is based on the amount of 

electricity required from an electric outlet to charge the vehicle and includes wall-to-vehicle 

charging losses. The values for all of the EVs and PHEVs reflect the electricity consumption 

rate required to operate the vehicle in either electric-only or blended mode operation. PHEVs 

that are capable of operating in a blended mode may also consume some gasoline in addition 

to electricity. Any additional gasoline used is shown in the fifth column. For example, the 

Prius PHEV consumes 29 kWh and 0.2 gallons of gasoline per 100 miles during this 

combination of electric-only and blended modes. 

99 
 

 

 

 

 

 

 

 

 

 

 

 

Table 7.3 

MY 2014 Alternative Fuel Vehicle Fuel Economy Label Metrics 

Make Model 

Fuel or 

Powertrain 

Charge Depleting Charge Sustaining Overall 

Fuel 

Economy 

(mpge) 

Electricity 

(kW-hrs/ 

100 miles) 

Gasoline 

(gallons/ 

100 miles) 

Fuel 

Economy 

(mpge) 

Fuel Economy 

(mpg) 

Chevrolet Spark EV 28 N/A 119 N/A 119 

BMW i3 EV 27 N/A 124 N/A 124 

BYD e6 EV 54 N/A 63 N/A 63 

Fiat 500e EV 29 N/A 116 N/A 116 

Ford Focus EV 32 N/A 105 N/A 105 

Honda Fit EV 29 N/A 118 N/A 118 

Mercedes-Benz B-class EV 40 N/A 84 N/A 84 

Mitsubishi i EV 30 N/A 112 N/A 112 

Nissan Leaf EV 30 N/A 114 N/A 114 

Smart Fortwo EV 32 N/A 107 N/A 107 

Tesla Model S (60kW-hr) EV 35 N/A 95 N/A 95 

Tesla Model S (85kW-hr) EV 38 N/A 89 N/A 89 

Toyota RAV4 EV 44 N/A 76 N/A 76 

BMW i3 REX PHEV 29 N/A 117 39 88 

BMW i8 PHEV 43 0.1 76 28 37 

Cadillac ELR PHEV 41 N/A 82 33 54 

Chevrolet Volt PHEV 35 N/A 98 37 62 

Ford C-MAX PHEV 37 0.0 88 38 51 

Ford Fusion PHEV 37 0.0 88 38 51 

Honda Accord PHEV 29 0.0 115 46 57 

McLaren P1 PHEV 25 5.7 18 17 17 

Porsche Panamera S PHEV 52 0.5 50 25 31 

Toyota Prius PHEV 29 0.2 95 50 58 

Honda Civic CNG N/A N/A N/A N/A 31 

The sixth column simply converts the electricity consumption data in the fourth column and 

the gasoline consumption data in the fifth column into a combined miles per gallon of 

gasoline-equivalent (mpge) metric. The mpge metric is a measure of the miles the vehicle can 

travel on an amount of energy that is equal to the amount of energy stored in a gallon of 

gasoline. For a vehicle operating on electricity, mpge is simply calculated as 33.705 kWhrs/gallon divided by the vehicle electricity consumption in kW-hrs/mile. For example, for the 

Leaf, 33.705 kW-hrs/gallon divided by 0.30 kW-hrs/mile, which is equivalent to 30 kWhrs/100 miles, is 114 mpge.13 Because the Prius PHEV consumes both electricity and gasoline 

over the alternative fuel range of 11 miles, the electric consumption value of 95 mpge includes 

both the electricity and gasoline consumption, at a rate of 29 kW-hrs/100 miles of electricity 

and 0.2 gal/100 miles of gasoline. 

The seventh column gives label fuel economy values for vehicles operating on gasoline only, 

which is relevant here only for the PHEVs operating in charge sustaining mode. For PHEVs, 

13 The actual calculations were done with unrounded numbers. Using the rounded numbers provided here may result in a slightly different 

100
 

number due to rounding error. 
 

 

 

 

 

 

 

 

 

 

 

 

the EPA/NHTSA label shows both electricity consumption in kW-hrs/100 miles and mpge, 

when the vehicle operates exclusively on electricity or in a blended mode, and gasoline fuel 

economy in mpg, when the vehicle operates exclusively on gasoline. 

The final column gives the overall mpge values reflecting the overall energy efficiency of the 

vehicle on all of the fuels on which the vehicle can operate. While mpge does not reflect how 

all alternative fuels are sold (natural gas is in fact sold in gallons of gasoline equivalent, but 

electricity is not), it does provide a common metric with which to compare fuels that are sold 

in different units, and mpge is generally included on the EPA/NHTSA labels for that reason. 

For PHEVs, the mpge metric can also be used to determine the overall equivalent fuel 

economy for a vehicle that operates on two unique fuels. In addition to the energy metrics in 

the previous columns, the one key additional parameter necessary to calculate a combined 

electricity/gasoline mpge value for a PHEV is the utility factor that was introduced in Table 

7.2. The MY 2014 Volt, for example, has a utility factor of 0.66, i.e., it is expected that, on 

average, the Volt will operate 66% of the time on electricity and 34% of the time on gasoline. 

Utility factor calculations are based on an SAE methodology that EPA has adopted for 

regulatory compliance (SAE 2010). For EVs and natural gas vehicles, the last column simply 

reports the mpge values that are on the EPA/NHTSA label. CNG vehicle mpge values are 

based on the energy equivalency assumption that a gallon of gasoline contains the same energy 

as 121.5 standard cubic feet of natural gas. 

Tables 7.4 and 7.5 show several key CO2 emissions metrics for MY 2014 alternative fuel 

vehicles. 

Table 7.4 gives vehicle tailpipe CO2 emissions values. EPA and vehicle manufacturers have 

been measuring tailpipe emissions since the early 1970s using standardized laboratory tests. 

Table 7.4 gives tailpipe CO2 emissions values that are included on the new EPA/DOT Fuel 

Economy and Environment labels (and reflected in the label’s Greenhouse Gas Rating) that 

are currently used for advanced technology vehicles. These label values reflect EPA’s best 

estimate of the CO2 tailpipe emissions that these vehicles will produce, on average, in real 

world city and highway operation based on the EPA 5-cycle label methodology and using a 

55% city/45% highway weighting. EVs, of course, have no tailpipe emissions. For the PHEVs, 

the label CO2 emissions values utilize the same utility factors discussed above to weight the 

CO2 emissions on electric and gasoline operation. For natural gas vehicles, these values are 

based on vehicle test data and our 5-cycle methodology. It is important to note that, to be 

consistent with CO2 emissions data elsewhere in this report, the tailpipe CO2 emissions values 

given in Table 7.4 for CNG vehicles do not account for the higher global warming potency 

associated with methane emissions, which have the potential to be higher for some CNG 

vehicles. 

101 
 

 

 

 

 

 

 

 

 

 

 

 

Table 7.4 

MY 2014 Alternative Fuel Vehicle Label Tailpipe CO2 Emissions Metrics 

Fuel or Tailpipe CO2 

Make Model Powertrain (g/mi) 

Chevrolet Spark EV 0 

BMW i3 EV 0 

BYD e6 EV 0 

Fiat 500e EV 0 

Ford Focus EV 0 

Honda Fit EV 0 

Mercedes-Benz B-class EV 0 

Mitsubishi i EV 0 

Nissan Leaf EV 0 

Smart Fortwo EV 0 

Tesla Model S (60kW-hr) EV 0 

Tesla Model S (85kW-hr) EV 0 

Toyota RAV4 EV 0 

BMW i3REX PHEV 40 

BMW i8 PHEV 198 

Cadillac ELR PHEV 91 

Chevrolet Volt PHEV 81 

Ford C-MAX PHEV 129 

Ford Fusion PHEV 129 

Honda Accord PHEV 130 

McLaren P1 PHEV 463 

Porsche Panamera S PHEV 206 

Toyota Prius PHEV 133 

Honda Civic CNG 218 

Table 7.5 accounts for the “upstream” CO2 emissions associated with the production and 

distribution of electricity used in EVs and PHEVs. Gasoline and diesel fuels also have CO2 

emissions associated with their production and distribution, but these upstream emissions are 

not reflected in the tailpipe CO2 emissions values discussed elsewhere in this report. 

Combining vehicle tailpipe and fuel production/distribution sources, gasoline vehicles emit 

about 80 percent of total CO2 emissions at the vehicle tailpipe with the remaining 20 percent 

of total CO2 emissions associated with upstream fuel production and distribution. Diesel fuel 

has a similar approximate relationship between tailpipe and upstream CO2 emissions. CNG 

vehicle upstream CO2 emissions data is not included in Table 7.5.

14 On the other hand, 

vehicles powered by grid electricity emit no CO2 (or other emissions) at the vehicle tailpipe; 

therefore all CO2 emissions associated with an EV are due to fuel production and distribution. 

Depending on how the electricity is produced, these fuels can have very high fuel 

production/distribution CO2 emissions (for example, if coal is used with no CO2 emissions 

control) or very low CO2 emissions (for example, if renewable processes with minimal fossil 

energy inputs are used). 

14 There is considerable uncertainly and ongoing research on the topic of GHG emissions from natural gas production, particularly with 

respect to hydraulic fracturing (“fracking”) processes. 

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An additional complicating factor in Table 7.5 is that electricity production in the United 

States varies significantly from region to region. Hydroelectric plants provide a large 

percentage of electricity in the northwest, coal-fired power plants produce the majority of 

electricity in the Midwest, and natural gas has increased its electricity market share in many 

regions of the country. Nuclear power plants and renewable energy make up the balance of 

U.S. electricity production. In order to bracket the possible GHG emissions impact, Table 7.5 

provides ranges with the low end of the range corresponding to the California powerplant 

emissions factor, the middle of the range represented by the national average powerplant 

emissions factor, and the upper end of the range corresponding to the powerplant emissions 

factor for the Rockies. 

Based on data from EPA’s eGRID powerplant database (TranSystems|E.H. Pechan 2014), and 

accounting for additional greenhouse gas emissions impacts for feedstock processing upstream 

of the powerplant (Argonne 2014), EPA estimates that the electricity GHG emission factors 

for various regions of the country vary from 346 g CO2/kW-hr in California to 986 g 

CO2/kW-hr in the Rockies, with a national average of 648 g CO2/kW-hr. Emission rates for 

the region encompassing New York City are approximately equal to those in California, and 

small regions in upstate New York and Alaska have lower electricity upstream CO2 emission 

rates than California. However, California is a good surrogate for the “low” end of the range 

because California is a leading market for current EVs and PHEVs. Initial sales of electric 

vehicles have been largely, though not exclusively, focused in regions of the country with 

powerplant CO2 emissions factors lower than the national average, such as California, New 

York, and other coastal areas. Accordingly, in terms of CO2 emissions, EPA believes that the 

current “sales-weighted average” vehicle operating on electricity in the near term will likely fall 

somewhere between the low end of this range and the national average.15 

The fourth through sixth columns in Table 7.5 provide the range of tailpipe plus total 

upstream CO2 emissions for EVs and PHEVs based on regional electricity emission rates. For 

comparison, the average MY 2014 car is also included in Table 7.5. The methodology used to 

calculate the range of tailpipe plus total upstream CO2 emissions for EVs, is shown in the 

following example for the MY 2014 Nissan Leaf: 

•	 Start with the label (5-cycle values weighted 55% city/45% highway) vehicle electricity 

consumption in kW-hr/mile, which for the Leaf is 30 kW-hr/100 miles, or 0.30 kWhr/mile 

•	 Determine the regional powerplant emission rate, regional losses during electricity 

distribution, and the additional regional emissions due to fuel production upstream 

of the powerplant (for California, these numbers are 277 g/kW-hr, 6.8%, and 16%). 

15 For an individual who wants to know the upstream greenhouse gas emissions associated with operating an EV or PHEV in his or her 

geographical area, use the emissions calculator at fueleconomy.gov/feg/Find.do?action=bt2 

103
 
 

 

 

 

 

 

 

 

 

 

 

 

•	 Determine the regional upstream emission factor (for California 277 g/kW-hr / (1-

0.068) * (1+0.16) = 346 gCO2/kW-hr) 16 

•	 Multiply by the range of Low (California = 346 gCO2/kW-hr), Average (National 

Average = 648 gCO2/kW-hr), and High (Rockies = 986 gCO2/kW-hr) electricity 

upstream GHG emission rates, which yields a range for the Leaf of 104-296 

grams/mile. 

The tailpipe plus total upstream CO2 emissions values for PHEVs include the upstream CO2 

emissions associated with electricity operation and both the tailpipe and upstream CO2 

emissions associated with gasoline operation, using the utility factor discussed above to weight 

the values for electricity and gasoline operation. The tailpipe plus total upstream CO2 

emissions values for the average car are the average MY 2014 car tailpipe CO2 emissions (from 

Table 4.3) multiplied by 1.25 to account for upstream emissions due to gasoline production. 

The values in columns four through six are tailpipe plus total upstream CO2 emissions. But, all 

of the gasoline and diesel vehicle CO2 emissions data in the rest of this report refer to tailpipe 

only emissions and do not reflect the upstream emissions associated with gasoline or diesel 

production and distribution. Accordingly, in order to equitably compare the overall relative 

impact of EVs and PHEVs with tailpipe emissions of petroleum-fueled vehicles, EPA uses the 

metric “tailpipe plus net upstream emissions” for EVs and PHEVs (note that this same 

approach has been adopted for EV and PHEV regulatory compliance with the 2012-2025 

light-duty vehicle GHG emissions standards for sales of EVs and PHEVs in MY 2012-2016 

and MY 2022-2025 that exceed sales thresholds). The net upstream emissions for an EV is 

equal to the total upstream emissions for the EV minus the upstream emissions that would be 

expected from a comparable-sized (size is a good first-order measure for utility and footprint is 

the size-based metric used for standards compliance) gasoline vehicle. The net upstream 

emissions for PHEVs are equal to the net upstream emissions of the PHEV due to electricity 

consumption in electric or blended mode multiplied by the utility factor. The net upstream 

emissions for a gasoline vehicle are zero. 

For each EV or PHEV, the upstream emissions for a comparable gasoline vehicle are 

determined by first using the footprint based compliance curves to determine the CO2 

compliance target for a vehicle with the same footprint. Since upstream emissions account for 

approximately 20% of total CO2 emissions for gasoline vehicles, the upstream emissions for 

the comparable gasoline vehicle are equal to one fourth of the tailpipe-only compliance target. 

The final three columns of Table 7.5 give the tailpipe plus net upstream CO2 values for the 

EVs and PHEVs using the same Low, Average, and High electricity upstream CO2 emissions 

rates discussed above. These values bracket the possible real world net CO2 emissions that 

would be associated with consumer use of these vehicles. For the Leaf, these values are simply 

the values in columns four through six minus the upstream GHG emissions of a comparably 

16 The actual calculations were done with unrounded numbers. Using the rounded numbers provided here may result in a slightly different 

number due to rounding error. 

104 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

sized gasoline vehicle. Based on the MY 2014 CO2 footprint curve, the 5-cycle tailpipe GHG 

emissions for a Leaf-sized gasoline vehicle meeting its compliance target would be 

approximately 307 grams/mi, with upstream emissions of one-fourth of this value, or 77 g/mi. 

The net upstream for the Leaf are determined by subtracting this value, 77 g/mi, from the 

total upstream emissions for the Leaf. The result is a range for the tailpipe plus net upstream 

value of 27-219 g/mile as shown in Table 7.5, with a more likely typical value in the 27-118 

g/mi range. 

For PHEVs, the tailpipe plus net upstream emissions values use the utility factor values 

discussed above to weight the individual values for electric operation and gasoline operation. 

Table 7.5 

MY 2014 Alternative Fuel Vehicle Upstream CO2 Emission Metrics 

Make Model 

Fuel or 

Powertrain 

Tailpipe + Total Upstream CO2 

Low Avg High 

(g/mi) (g/mi) (g/mi) 

Tailpipe + Net Upstream CO2 

Low Avg High 

(g/mi) (g/mi) (g/mi) 

Chevrolet Spark EV 97 181 276 26 110 205 

BMW i3 EV 93 175 266 18 100 191 

BYD e6 EV 187 350 532 103 266 449 

Fiat 500e EV 101 189 288 30 118 216 

Ford Focus EV 111 208 316 35 132 241 

Honda Fit EV 99 185 281 27 114 210 

Mercedes-Benz B-class EV 138 259 394 61 182 317 

Mitsubishi i EV 104 195 296 33 123 225 

Nissan Leaf EV 104 194 296 27 118 219 

Smart Fortwo EV 109 204 311 38 133 239 

Tesla Model S (60kW-hr) EV 122 229 348 32 139 258 

Tesla Model S (85kW-hr) EV 131 246 374 41 156 284 

Toyota RAV4 EV 153 287 436 76 210 360 

BMW i3 REX PHEV 134 207 288 61 134 216 

BMW i8 PHEV 303 351 404 223 271 324 

Cadillac ELR PHEV 206 286 377 132 213 303 

Chevrolet Volt PHEV 180 249 326 109 178 255 

Ford C-MAX PHEV 219 269 326 153 203 259 

Ford Fusion PHEV 219 269 326 150 200 256 

Honda Accord PHEV 196 225 257 136 165 198 

McLaren P1 PHEV 617 650 687 466 499 536 

Porsche Panamera S PHEV 328 389 457 242 303 372 

Toyota Prius PHEV 195 221 249 140 165 194 

Average Car Gasoline 400 400 400 320 320 320 

While there are still relatively few OEM alternative fuel vehicles in MY 2014, this represents a 

significant increase in both the number of models available and the total production of 

alternative fuel vehicles. Based on manufacturer announcements and projected sales, this 

segment of the market will continue to grow in MY 2015 and beyond. This report will 

continue to track the metrics presented in this section and report on trends in alternative fuel 

vehicle CO2 emissions and fuel economy as more models are introduced and more data 

becomes available in future years. 

105
 
 

 

 

 

 

 

 

D. OVERALL IMPACT OF ALTERNATIVE FUEL 

VEHICLES 

In the past, this report has treated alternative fuel vehicles separately from gasoline and diesel 

vehicles, with the vast majority of analysis limited to gasoline and diesel vehicles only. Since 

alternative fuel vehicle production has generally been less than 0.1% of total vehicle 

production until very recently, the impact of excluding alternative fuel vehicles was negligible. 

However, with alternative fuel vehicles now approaching 1% of new vehicle production, these 

vehicles are in fact beginning to have a measurable and meaningful impact on overall new 

vehicle fuel economy and CO2 emissions. 

Determining an equitable approach to integrate gasoline, diesel, and alternative fuel vehicles is 

challenging, as discussed earlier in this section. For the first time, this section presents a brief 

analysis of the impact of alternative fuel vehicles on overall new vehicle fuel economy and CO2 

emissions. In order to introduce this analysis, the authors chose to use the overall fuel 

economy in mpge, from Table 7.3, and the tailpipe CO2 emission values from Table 7.4 for 

alternative fuel vehicles. These values are used on the EPA/DOT Fuel Economy and 

Environment Label and are the metrics that are most often associated with these vehicles. 

Including net upstream CO2 emissions for vehicles operating on electricity, as shown in Table 

7.5, would reduce the positive impact of alternative fuel vehicles on fleetwide CO2 emissions. 

Table 7.6 shows the impact of alternative fuel vehicles on MY 2013 manufacturer adjusted 

mpg and CO2 emissions fleet averages. Unlike the discussion in the rest of this section, Table 

7.6 is based on MY 2013 vehicles, since final production values are available for MY 2013 

vehicles. Seven of the thirteen largest manufacturers produced AFVs in MY 2013. 

Additionally, three smaller manufacturers not discussed elsewhere in this report produced 

AFVs and are included (in italics). The alternative fuel vehicle fuel economy and CO2 

emissions values were recalculated from label values weighted 55% city and 45% highway, to 

adjusted values weighted 43% city and 57% highway to be consistent with the adjusted 

numbers presented in most of the sections of this report. For further discussion of the 

methodology behind the adjusted fuel economy and CO2 values, see Section 10. 

106 
 

 

 

 

 

 

 

 

 

Table 7.6 

MY 2013 Alternative Fuel Vehicle Impact on Manufacturer Averages 

Adjusted Fuel Economy Adjusted Tailpipe CO2 

Total 

Sales 

Without AFV % 

AFVs 

(mpg) 

With AFVs 

(mpge) 

Change 

(mpge) 

Without 

AFVs 

(g/mi) 

With AFVs 

(g/mi) 

Change 

(g/mi) 

Nissan 

General Motors 

Ford 

Toyota 

Daimler 

Chrysler-Fiat 

Honda 

Tesla 

Coda 

BYD 

All 

26.2 26.6 0.4 

22.0 22.2 0.2 

22.2 22.3 0.1 

25.1 25.2 0.1 

22.4 22.5 0.1 

20.9 20.9 0.0 

27.4 27.4 0.0 

n/a 90.6 n/a 

n/a 72.0 n/a 

n/a 63.2 n/a 

24.1 24.2 0.1 

339 332 -7 

404 400 -4 

400 398 -2 

354 353 -1 

399 398 -1 

425 424 -1 

324 324 0 

n/a 0 n/a 

n/a 0 n/a 

n/a 0 n/a 

369 366 -3 

26,167 

27,484 

18,525 

11,129 

880 

2,353 

985 

17,813 

37 

32 

2.0% 

1.2% 

0.8% 

0.5% 

0.3% 

0.2% 

0.1% 

100% 

100% 

100% 

0.7% 

Alternative fuel vehicles comprised 0.7% of new vehicle production in MY 2013. Including 

mpge and tailpipe CO2 emissions from alternative fuel vehicles increases the overall MY 2013 

new vehicle fuel economy by 0.1 mpg, and reduces the overall CO2 emissions by 3 g/mi. Of 

the largest manufacturers with production of over 100,000 vehicles (see section 4), Nissan had 

the highest concentration of AFV production at 2.0%, followed by GM at 1.2%. Including 

AFVs improves Nissan’s performance the most, increasing MY 2013 fuel economy by 0.4 

mpge overall, and decreasing Nissan’s MY 2013 CO2 emissions by 7 g/mi. 

Tesla, which sells exclusively EVs, had the highest fuel economy of any manufacturer in terms 

of mpge. Coda and BYD are two additional manufacturers that produced only EVs in MY 

2013, albeit in very small numbers. 

The impact of AFVs on overall manufacturer numbers is still relatively small, and does not 

change the manufacturer rankings, for either adjusted fuel economy or adjusted CO2 

emissions, that are shown in Tables 4.2 and 4.3. This report will continue to track alternative 

fuel vehicles and may show more analysis including alternative fuel vehicles in future reports. 

This will be especially important if sales of alternative fuel vehicles continue to increase at the 

rapid rate of the last three years. 

107
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

High Fuel Economy/Low CO2 and
 

Advanced Technology Choices
 Consumers shopping for vehicles with comparatively high fuel economy and low tailpipe CO2 emissions have 

more vehicles to choose among in MY 2014 than five years earlier. These choices reflect both a more diverse 

range of technology packages on conventional gasoline vehicles as well as more advanced technology and 

alternative fuel vehicles. Section 5 analyzes important trends for a number of conventional gasoline and diesel 

vehicle technologies and for advanced technologies like hybrid vehicles. Section 7 provides data on individual 

alternative fuel vehicle models such as electric vehicles, plug-in hybrid electric vehicles, and compressed natural 

gas vehicles. This section focuses specifically on trends related to the fuel economy and advanced vehicle 

purchase choices available to consumers in the new vehicle market. 

A. METHODOLOGY 

There are some important methodological differences in the analysis in this section relative to 

Sections 1-6. First, the data in this section are not weighted by vehicle production levels, but 

instead reflect “model counts,” which is more appropriate for evaluating vehicle choices for 

consumers. This is because, to an individual consumer in the market for a new vehicle, it 

makes little or no difference if a particular model has high or low production. Second, this 

section includes alternative fuel vehicles, whereas sections 1-6 generally analyze only gasoline 

and diesel vehicles. Third, the analysis in this section focuses on the changes between MY 

2009 and MY 2014, rather than trends over multiple decades. These two model years are used 

because a 5-year period is long enough to identify meaningful multi-year trends. 

This “model count” analysis requires assumptions about how to define a model. Our objective 

in this analysis is to count models that are generally marketed and perceived by consumers to 

be unique vehicle choices, but not to count multiple configurations that are generally 

marketed and perceived by consumers to be the same model. The application of this approach 

requires considerable judgment, and we have made every effort to be consistent for both MY 

2009 and MY 2014. The most important guidelines used to classify vehicle configurations 

into unique “models” for this analysis are: 

•	 Vehicles with the same name are generally counted as one model (e.g., all Honda Civics 

are counted as one model), with exceptions noted below. Vehicle options included as one 

model include: 

o	 Engine and transmission options (including hybrid, diesel, CNG, EV, PHEV, 

turbo, and ECO variants) 

o	 2WD and 4WD versions 

o	 Trim levels 

o	 Convertible, hatchback, and wagon body styles 

o	 FFV and non-FFV models 

o	 BMW series. For example, all BMW 5 series variants are included as one model, 

including the ActiveHybrid 5 

108 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 The model count methodology was updated for this year’s report to better capture 

performance vehicles with their base counterparts. Generally performance and nonperformance vehicles are counted as one model, even if they have distinct names. Vehicle 

variants counted as one model include: 

o	 Audi A4 and Audi S4 

o	 BMW M3 in included in the BMW 3 series 

o	 Volkswagen Golf and Volkswagen GTI 

•	 Vehicles that are substantially similar, but are sold in multiple divisions, (often called 

“twins”) are counted as separate models. For example: 

o	 Ford Escape and Mercury Mariner are counted as separate models 

o	 Chevrolet Equinox and GMC Terrain are counted as separate models 

•	 Vehicles that are generally marketed as distinct models are counted as separate models. 

For example: 

o	 Prius, Prius v and Prius c are counted as distinct models 

•	 The model count methodology was updated for this year’s report, such that the Mini 

Cooper vehicles are grouped and counted as four models (Mini Cooper, Mini Cooper 

Roadster, Mini Cooper Clubman, Mini Cooper Countryman/Paceman), generally based 

on wheelbase, with multiple trim models within each wheelbase counted as the same 

model 

•	 If at least one variant of an individual model meets a threshold defined in the analysis
 

(e.g., cars with fuel economy greater than 30 mpg), the model is counted only once,
 

regardless of the number of model variants that meet the threshold. For instance, if
 

hybrid, CNG, and gasoline variant Honda Civics exceed 30 mpg, only one Civic is
 

counted as exceeding 30 mpg
 

These “model count” guidelines resulted in approximately 300 models for both MY 2009 and 

MY 2014. 

Finally, the last methodological difference between this section and most other sections of this 

report is that two key parameters -vehicle classifications and combined city/highway fuel 

economy values- are generally aligned with the Fuel Economy and Environment label in order 

to be consistent with the information available to consumers when they are considering new 

vehicle purchases. The vehicle classifications in Figure 8.1 are based on Fuel Economy and 

Environment label classifications which differ slightly from the definitions of cars and light 

trucks used in Sections 1-6 in this report (for example, in Figure 8.1, all SUVs are combined 

into a single category consistent with fuel economy labels and are not split into car SUVs and 

truck SUVs as is done for compliance with standards and elsewhere in this report). The label 

classes are simplified into four broader categories: cars, SUVs, pickups and minivans/vans. If 

variants of a model were in more than one of these four broader categories, then the variant 

was counted once in each relevant category. The combined fuel economy values used in Figure 

109 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8.1 are based on the 55% city/45% highway weighting used on fuel economy labels, and not 

on the 43% city/57% highway weighting used for adjusted fuel economy values presented 

elsewhere in this report. For PHEVs, the mpge value is the combined, utilitized value. These 

values can be found in the “Overall Fuel Economy” column of Table 7.3. 

B. HIGH FUEL ECONOMY VEHICLE OFFERINGS 

Figure 8.1 shows the change from MY 200917 to MY 2014 in the number of models for which 

at least one model variant meets various fuel economy thresholds. The threshold values for 

EVs, PHEVs, and CNG vehicles that are represented in Figure 8.1 all use miles per gallon of 

gasoline-equivalent (mpge), i.e., the miles the vehicle can travel on an amount of electricity 

that has the same amount of energy as a gallon of gasoline. See Section 7 for a detailed 

discussion of EVs, PHEVs, CNG vehicles, and mpge. 

Figure 8.1 

Number of Models Meeting Fuel Economy Thresholds in MY 2009 and MY 2014 

MY 2009 

MY 2014 

0 

20 

60 

Number of Models

40 

Pickups and 

Minivans/Vans ≥ 20 MPG 

SUVs ≥ 25 MPG Cars ≥ 30 MPG Cars ≥ 40 MPG 

Includes city/hwy combined

label MPG estimates for 

gasoline, diesel and hybrid

vehicles, and MPGe estimates 

for EVs and PHEVs 

10 

30 

50 

70 

Figure 8.1 shows that there are 16 MY 2014 pickup and minivan/van models for which at 

least one variant of the model has a combined city/highway label fuel economy rating of 20 

mpg or more, a slight increase over five years ago. Five minivans/vans met or exceeded a 20 

mpg threshold in MY 2009, but in MY 2014 more than ten minivans/vans meet the 20 mpg 

threshold. While the number of minivans/vans meeting or exceeding 20 mpg has increased in 

the last five years, the number of pickups has decreased as several small pickups are no longer 

produced. Three times as many MY 2014 SUV models achieve 25 mpg or above compared to 

MY 2009. Of the SUVs that achieved 25 mpg in MY 2009, more than half (five) were hybrids. 

More than 20 non-hybrid, gasoline or diesel SUVs achieve at least 25 mpg in MY 2014, as well 

as two electric, and six hybrid SUVs that achieve at least 25 mpg; These total to more than the 

17 The MY 2009 Tesla Roadster is included in this data. Before MY 2012, manufacturers that produced only EVs were not required to have 

an EPA fuel economy label; however, for purposes of figure 8.1, the MY 2009 Tesla Roadster is assumed to have fuel economy that is over 

40 MPGe and therefore meets the car thresholds for 30 MPGe and 40 MPGe. 

110 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

26 models shown in Figure 8.1 because two of the hybrid SUVs and one of the electric SUVs 

also has either a diesel or gasoline variant that crosses the 25 MPG threshold. There are now 

more than 60 car models available where at least one variant has a combined city/highway 

label fuel economy of 30 mpg or more, a more than three-fold increase over MY 2009. Of MY 

2014 car models that have a combined label value greater than or equal to 30 mpg, about half 

reach this threshold with at least one conventional gasoline or diesel variant. In addition, 

more than 25 MY 2014 cars achieve 40 mpg or higher, and 17 of the MY 2014 cars have at 

least one variant that achieves 50 mpg or higher. One of the MY 2014 cars that achieves at 

least 40 mpg is a conventional gasoline vehicle, but the rest of the cars achieving at least 40 

mpg consist of hybrid electric vehicles, electric vehicles and plug-in hybrid electric vehicles. 

C. ADVANCED TECHNOLOGY VEHICLE OFFERINGS 

Figure 8.2 shows that consumers also have many more alternatives to conventional gasoline 

vehicles. In MY 2009, the only advanced technologies for which there were meaningful 

choices were hybrids and diesels, with one EV and one dedicated compressed natural gas 

(CNG) vehicle. In MY 2014, there are almost twice as many hybrid offerings as there were in 

MY 2009. In addition, the number of diesel offerings has doubled, and there are growing 

numbers of electric vehicles and plug-in hybrid electric vehicles as well. In MY 2014 there are 

more than ten EVs; there are ten PHEVs; and there is one dedicated CNG vehicle.18 

Production share is also increasing for advanced technology vehicles. For a more detailed 

discussion of hybrids and diesel vehicles, see Section 5, and see Section 7 for more 

information about alternative fuel vehicles. 

For Figure 8.2, the “model count” methodology is modified slightly to allow models that have 

more than one alternative fuel variant to be counted in each alternative fuel category (e.g., a 

Ford Fusion is available as both an HEV and PHEV, so the model was counted once in each 

category). 

Figure 8.2 

Advanced Technology and Alternative Fueled Vehicle Models in MY 2009 and MY 2014 Number of Models 

40 

30 

20 

10 

0 

MY 2009 

MY 2014 

Diesel Hybrid EV PHEV CNG 

111 

18 Some advanced technology vehicles are generally available only in selected markets. Fuel cell vehicles may also be available to a small 

number of consumers in select markets through limited lease and/or demonstration programs, but are not included in this analysis. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Regulatory Context 

A. PERSONAL VEHICLE FUEL ECONOMY AND
 

GREENHOUSE GAS EMISSIONS STANDARDS
 

National fuel economy standards have been in place in the United States for cars and light 

trucks since 1978. The Department of Transportation, through the National Highway Traffic 

Safety Administration (NHTSA), has the responsibility for setting and enforcing fuel economy 

standards through the Corporate Average Fuel Economy (CAFE) program. Since the 

inception of fuel economy standards, EPA has been responsible for establishing fuel economy 

test procedures and calculation methods, and for collecting data used to determine vehicle fuel 

economy and manufacturer CAFE levels. 

For MY 2012 through 2025, EPA and NHTSA have jointly developed a historic and 

coordinated National Program, which established EPA greenhouse gas emissions standards 

and NHTSA CAFE standards that allow manufacturers to build a single national fleet to meet 

requirements of both programs while ensuring that consumers have a full range of vehicle 

choices. The standards have been supported by a wide range of stakeholders: most major 

automakers, the United Auto Workers, the State of California, and major consumer and 

environmental groups. 

In 2010, the agencies finalized the first coordinated standards for MY 2012-2016 (75 Federal 

Register 25324, May 7, 2010). By MY 2016, the average industry-wide compliance levels for 

these footprint-based standards are projected to be 250 g/mi CO2 and 34.1 mpg CAFE. The 

250 g/mi CO2 compliance level would be equivalent to 35.5 mpg if all CO2 emissions 

reductions are achieved through fuel economy improvements. In 2012, the agencies finalized 

additional coordinated standards for MY 2017-2025 (77 Federal Register 62624, October 15, 

2012). By MY 2025, the average industry-wide compliance levels are projected to be 163 g/mi 

CO2 and 48.7 to 49.7 mpg CAFE.19 20 The 163 g/mi CO2 compliance level would be 

equivalent to 54.5 mpg if all CO2 emissions reductions are achieved solely through 

improvements in fuel economy.21 For both MY 2012-2016 and MY 2017-2025, the agencies 

expect that a portion of the required CO2 emissions improvements will be achieved by 

reductions in air conditioner refrigerant leakage, which would not contribute to higher fuel 

economy. These coordinated standards are expected to yield “continuous improvement” 

reductions in CO2 emissions and increases in fuel economy levels through MY 2025. 

19 The final rule establishing these standards requires EPA to conduct a midterm evaluation of the MY 2022-2025 standards.
 20 NHTSA CAFE standards for model years 2022-2025 are not final, and are augural. NHTSA is required by Congress to set CAFE standards
 

for no more than five years at a time. NHTSA will conduct a new and full rulemaking in the future to establish standards for model years 

2022-2025. NHTSA projects the augural standards would require a combined fleetwide fuel economy of 48.7-49.7 mpg.
 21 While many assumptions must be made to convert from projected standards compliance levels to projected adjusted (real world) levels,
 

EPA has projected that MY 2025 standards compliance levels, with no over compliance, would result in adjusted levels of 223 g/mi CO2 and 

40 mpg (77 Federal Register 62773, October 15, 2012).
 

112
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Prior to the national program, truck CAFE standards began to increase in MY 2005, and have 

increased every year since. Truck CAFE standards were constant from MY 1996 – MY 2004, 

and car CAFE standards were constant from MY 1990 until MY 2010. 

Automaker compliance with the above CO2 and CAFE standards is based on unadjusted, 

laboratory CO2 and fuel economy values, along with various regulatory incentives and credits, 

rather than on the adjusted CO2 and fuel economy values that are used throughout most of 

this report. Neither unadjusted, laboratory nor adjusted CO2 and fuel economy values reflect 

various incentives (e.g., for flexible fuel vehicles for both CO2 and CAFE standards) and 

credits (air conditioner and other off-cycle technologies for CO2 standards) that are available 

to manufacturers for regulatory compliance. Fleetwide CAFE standards compliance values are 

a minimum of 25% higher than adjusted fuel economy values and fleetwide CO2 emissions 

standards compliance values are a minimum of 20% lower than adjusted CO2 emissions values 

(these offsets can be greater due to alternative fuel vehicle, air conditioner, and/or other 

compliance credits). EPA (at epa.gov/otaq/regs/ld-hwy/greenhouse/ld-ghg.htm) and NHTSA 

(at nhtsa.dot.gov/fuel-economy) publish separate documents summarizing formal automaker 

compliance with GHG emissions and CAFE standards. NHTSA will prepare an updated 

report after EPA provides NHTSA with complete and final data through MY 2013. NHTSA 

may also update this report at other times when additional data is available. 

B. CURRENT VEHICLES THAT MEET FUTURE EPA 

CO2 EMISSIONS COMPLIANCE TARGETS 

This section evaluates MY 2014 vehicles against future footprint-based CO2 emission targets to 

determine which current vehicles could meet or exceed their targets in model years 2016-2025, 

based on current powertrain designs and only assuming credits for future improvements in air 

conditioner refrigerants and efficiency. EPA assumed the addition of air conditioning 

improvements since these are considered to be among the most straightforward and least 

expensive technologies available to reduce CO2 and other greenhouse gas emissions. 

It is important to note there are no CO2 emissions standards for individual vehicles. Rather, 

there are manufacturer-specific compliance levels for both passenger car and light truck fleets. 

The compliance levels are derived from the footprint-based CO2 emissions target curves, and 

the production volume-weighted distribution of vehicles produced for sale in the U.S. by each 

manufacturer. Since vehicles with emissions levels below their CO2 targets will generate 

credits (and those above their targets will generate debits), manufacturers are likely to achieve 

fleetwide compliance with 40% to 60% of their models meeting or bettering their targets. 

Figure 9.1 shows that 34% of projected MY 2014 vehicle production already meets the MY 

2016 CO2 targets, or can meet these targets with the addition of expected air conditioning 

improvements. The bulk of current vehicle production that meets the MY 2016 targets is 

accounted for by non-hybrid gasoline vehicles, although other technologies, including diesels, 

113 
 

 

 

 

hybrids, plug-in hybrid electric vehicles, electric vehicles and compressed natural gas vehicles, 

are also represented. 

Looking ahead, nearly 4% of projected 2014 production already meets the MY 2025 CO2 

targets. Vehicles meeting the MY 2025 CO2 targets are comprised solely of hybrids, plug-in 

hybrids, and electric vehicles. Since the MY 2025 standards are over a decade away, there’s 

considerable time for continued improvements in gasoline vehicle technology. 

Figure 9.1 

MY 2014 Vehicle Production That Meets Future CO2 Emission Targets with Current Powertrains 

40% 

35% 

30% Fuel 

CNG 

25% 

EV 

PHEV 

HEV 

15% 

20% 

Diesel 

Gasoline 

10% 

5% 

0% 

2016 2017 2020 2025 

Target Year 

114
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

C. COMPARISON OF EPA AND NHTSA FUEL 

ECONOMY DATA, 1975-2014 

Table 9.1 compares CAFE performance data reported by NHTSA (“Summary of Fuel 

Economy Performance” report dated June 26, 2014 and available at nhtsa.dot.gov/fueleconomy) with the adjusted and unadjusted, laboratory fuel economy data in this report. With 

only minor exceptions over 30 years ago, the NHTSA values are higher than the EPA 

unadjusted, laboratory values, due primarily to alternative fuel vehicle credits, and secondarily 

to test procedure adjustment factors for cars. In recent years for which both Agencies report 

final data, the NHTSA values are typically 0.6-1.0 mpg higher than the EPA unadjusted, 

laboratory values. MY 2012 is the most recent year for which both agencies report final data, 

and NHTSA’s final CAFE performance value is 1.0 mpg higher than EPA’s final unadjusted, 

laboratory value. For MY 2013, NHTSA’s mid-model year value does not include Hyundai and 

Kia due to the ongoing fuel economy investigation, however EPA’s final unadjusted, 

laboratory value does include Hyundai and Kia. Accordingly, the smaller 0.4 mpg difference is 

to be expected. For MY 2014, both agencies report preliminary values, and NHTSA’s 

preliminary value is 1.0 mpg higher (1.0 mpg for cars and 1.2 mpg higher for trucks) than 

EPA’s unadjusted, laboratory value. These preliminary MY 2014 projections are based on 

different data sets. The EPA MY 2014 value is based on automaker submissions in the spring 

and summer of 2013 to support vehicle fuel economy labels. The NHTSA MY 2014 value is 

based on automaker pre-model year CAFE reports later in 2013. Final MY 2014 results will be 

reported in next year’s report. 

The EPA car and truck fuel economy values shown in Table 9.1 for years prior to MY 2011 

differ from the values found elsewhere in this report. Beginning with the 2011 report, EPA 

reclassified many small and mid-sized, 2-wheel drive SUVs from trucks to cars for the entire 

historical database. This reflects a regulatory change made by NHTSA for CAFE standards 

beginning in MY 2011 and applies to the joint EPA/NHTSA greenhouse gas emissions and 

CAFE standards that have been finalized for MY 2012-2025. These changes were not in effect 

for years prior to MY 2011, and accordingly NHTSA’s CAFE fuel economy values prior to MY 

2011 are based on the previous car and truck definitions. To enable an apples-to-apples 

comparison to the NHTSA values, the EPA car and truck values in Table 9.1 through model 

year 2010 were calculated using the previous car and truck definitions, which is not consistent 

with the rest of this report. While the individual car and truck values in Table 9.1 are unique, 

the car and truck definitions do not affect the overall (car plus truck) fuel economy values, 

which are consistent with the rest of this report. 

115 
 

 

 

Table 9.1 

EPA Adjusted, EPA Unadjusted Laboratory, and CAFE Values by Model Year 

Model 

Year 

Cars Trucks Both Cars and Trucks 

EPA 

Adj. 

(MPG) 

EPA 

Unadj., 

Lab 

(MPG) 

NHTSA 

CAFE 

(MPG) 

Diff. 

(NHTSA 

- Lab) 

(MPG) 

EPA Adj. 

(MPG) 

EPA 

Unadj., 

Lab 

(MPG) 

NHTSA 

CAFE 

(MPG) 

Diff. 

(NHTSA -

Lab) 

(MPG) 

EPA 

Adj. 

(MPG) 

EPA 

Unadj., 

Lab 

(MPG) 

NHTSA 

CAFE 

(MPG) 

Diff. 

(NHTSA -

Lab) 

(MPG) 

1975 13.5 15.8 N/A - 11.6 13.7 N/A - 13.1 15.3 N/A -

1976 14.9 17.5 N/A - 12.2 14.4 N/A - 14.2 16.7 N/A -

1977 15.6 18.3 N/A - 13.3 15.6 N/A - 15.1 17.7 N/A -

1978 16.9 19.9 19.9 0.0 12.9 15.2 N/A - 15.8 18.6 19.9 1.3 

1979 17.2 20.3 20.3 0.0 12.5 14.7 18.2 3.5 15.9 18.7 20.1 1.4 

1980 20.0 23.5 24.3 0.8 15.8 18.6 18.5 -0.1 19.2 22.5 23.1 0.6 

1981 21.4 25.1 25.9 0.8 17.1 20.1 20.1 - 20.5 24.1 24.6 0.5 

1982 22.2 26.0 26.6 0.6 17.4 20.5 20.5 - 21.1 24.7 25.1 0.4 

1983 22.1 25.9 26.4 0.5 17.8 20.9 20.7 -0.2 21.0 24.6 24.8 0.2 

1984 22.4 26.3 26.9 0.6 17.4 20.5 20.6 0.1 21.0 24.6 25.0 0.4 

1985 23.0 27.0 27.6 0.6 17.5 20.6 20.7 0.1 21.3 25.0 25.4 0.4 

1986 23.7 27.9 28.2 0.3 18.2 21.4 21.5 0.1 21.8 25.7 25.9 0.2 

1987 23.8 28.1 28.5 0.4 18.3 21.6 21.7 0.1 22.0 25.9 26.2 0.3 

1988 24.1 28.6 28.8 0.2 17.9 21.2 21.3 0.1 21.9 25.9 26.0 0.1 

1989 23.7 28.1 28.4 0.3 17.6 20.9 21.0 0.1 21.4 25.4 25.6 0.2 

1990 23.3 27.8 28.0 0.2 17.4 20.7 20.8 0.1 21.2 25.2 25.4 0.2 

1991 23.4 28.0 28.4 0.4 17.8 21.3 21.3 - 21.3 25.4 25.6 0.2 

1992 23.1 27.6 27.9 0.3 17.4 20.8 20.8 - 20.8 24.9 25.1 0.2 

1993 23.5 28.2 28.4 0.2 17.5 21.0 21.0 - 20.9 25.1 25.2 0.1 

1994 23.3 28.0 28.3 0.3 17.2 20.8 20.8 - 20.4 24.6 24.7 0.1 

1995 23.4 28.3 28.6 0.3 17.0 20.5 20.5 - 20.5 24.7 24.9 0.2 

1996 23.3 28.3 28.5 0.2 17.2 20.8 20.8 - 20.4 24.8 24.9 0.1 

1997 23.4 28.4 28.7 0.3 17.0 20.6 20.6 - 20.1 24.5 24.6 0.1 

1998 23.4 28.5 28.8 0.3 17.1 20.9 21.0 0.1 20.1 24.5 24.7 0.2 

1999 23.0 28.2 28.3 0.1 16.7 20.5 20.9 0.4 19.7 24.1 24.5 0.4 

2000 22.9 28.2 28.5 0.3 16.9 20.8 21.3 0.5 19.8 24.3 24.8 0.5 

2001 23.0 28.4 28.8 0.4 16.7 20.6 20.9 0.3 19.6 24.2 24.5 0.3 

2002 23.1 28.6 29.0 0.4 16.7 20.6 21.4 0.8 19.5 24.1 24.7 0.6 

2003 23.2 28.9 29.5 0.6 16.9 20.9 21.8 0.9 19.6 24.3 25.1 0.8 

2004 23.1 28.9 29.5 0.6 16.7 20.8 21.5 0.7 19.3 24.0 24.6 0.6 

2005 23.5 29.5 30.3 0.8 17.2 21.4 22.1 0.7 19.9 24.8 25.4 0.6 

2006 23.3 29.2 30.1 0.9 17.5 21.8 22.5 0.7 20.1 25.2 25.8 0.6 

2007 24.1 30.3 31.2 0.9 17.7 22.1 23.1 1.0 20.6 25.8 26.6 0.8 

2008 24.3 30.5 31.5 1.0 18.2 22.7 23.6 0.9 21.0 26.3 27.1 0.8 

2009 25.4 32.1 32.9 0.8 19.0 23.8 24.8 1.0 22.4 28.2 29.0 0.8 

2010 25.8 32.7 33.9 1.2 19.1 23.8 25.2 1.4 22.6 28.4 29.3 0.9 

2011 25.6 32.3 33.1 0.8 19.1 23.9 24.7 0.8 22.4 28.1 29.0 0.9 

2012 27.0 34.3 35.3 1.0 19.3 24.1 25.0 0.9 23.6 29.8 30.8 1.0 

2013 27.6 35.2 36.0 0.8 19.8 24.8 25.5 0.7 24.1 30.5 30.9 0.4 

2014 27.9 35.5 36.5 1.0 20.1 25.2 26.4 1.2 24.2 30.6 31.6 1.0 

116 
 

 

 

 

 

 

 

 

 

 

D. COMPARISON OF MY 2013 UNADJUSTED, 

LABORATORY AND ESTIMATED CAFE DATA BY 

MANUFACTURER 

The primary differences between EPA unadjusted, laboratory fuel economy data and EPA 

estimated CAFE values are flexible fuel vehicle (FFV) credits that are available to 

manufacturers that produce vehicles capable of operation on an alternative fuel (E85, a blend 

of 85 percent ethanol and 15 percent gasoline), and test procedure adjustment (TPA) credits 

that apply to manufacturers of passenger cars. Any remaining offsets are due to production of 

alternative fuel vehicles, which are not included in the unadjusted, laboratory fuel economy 

values provided in this report (see Section 7, Alternative Fuel Vehicles). 

Table 9.2 shows how the unadjusted, laboratory fuel economy values in this report, the 

production of alternative fueled vehicles (AFVs), FFV credits, and TPA credits “add up” to 

estimated CAFE values for each of the eleven highest volume manufacturers (excluding 

Hyundai and Kia) for cars, trucks, and cars plus trucks. The FFV credits, TPA credits, and 

estimated CAFE values in Table 9.2 were obtained directly from EPA’s fuel economy 

compliance program. The data is from the annual manufacturer CAFE Reports, and based on 

data provided to EPA and NHTSA by automakers. The authors calculated the impact of AFVs 

on CAFE levels for those manufacturers that produce AFVs. For some manufacturers, the 

numbers in Table 9.2 do not add up exactly due to rounding. 

The CAFE program recognizes three categories, domestic passenger vehicles, import passenger 

vehicles, and light trucks. The passenger car FFV, TPA, and estimated CAFE numbers in 

Table 9.2 are calculated from the domestic and import passenger vehicle categories. The truck 

values were obtained directly (trucks are not eligible for TPA credits). The combined car and 

truck FFV and TPA credits were generated using car and truck sales. This column is shown for 

illustrative purposes only, since there are no CAFE standards for combined cars and trucks. 

For MY 2013, five manufacturers earned FFV credits for cars and seven manufacturers did so 

for trucks. All manufacturers were eligible for the TPA credits for cars. 

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Table 9.2 

Comparison of MY 2013 EPA Unadjusted, Laboratory and Estimated CAFE (MPG) Values by 

Manufacturer* 

Manufacturer 

Passenger Car Light Truck Both Cars and Trucks 

EPA 

Unadj., 

Lab AFVs 

FFV 

Credit 

TPA 

Credit 

Est. 

CAFE** 

EPA 

Unadj., 

Lab AFVs 

FFV 

Credit 

TPA 

Credit 

Est. 

CAFE** 

EPA 

Unadj., 

Lab AFVs 

FFV 

Credit 

TPA 

Credit 

Est. 

CAFE** 

Ford 34.5 0.4 1.2 0.3 36.3 23.8 0.0 1.2 0.0 25.0 27.9 0.2 1.2 0.1 29.4 

General Motors 32.1 0.4 1.2 0.2 33.9 22.6 0.0 1.2 0.0 23.8 27.5 0.2 1.2 0.1 29.0 

Toyota 39.3 0.2 0.0 0.4 39.9 25.4 0.0 0.5 0.0 26.0 32.2 0.1 0.3 0.1 32.8 

Chrysler-Fiat 30.6 0.1 1.2 0.2 32.1 23.4 0.0 1.2 0.0 24.5 26.0 0.0 1.2 0.1 27.3 

Honda 39.0 0.0 0.0 0.4 39.4 28.5 0.0 0.0 0.0 28.5 34.9 0.0 0.0 0.2 35.2 

Nissan 37.8 1.0 0.0 0.3 39.1 26.5 0.0 0.6 0.0 27.1 33.6 0.6 0.3 0.2 34.7 

Volkswagen 33.2 0.0 0.8 0.2 34.2 27.1 0.0 1.2 0.0 28.3 32.2 0.0 0.9 0.2 33.3 

BMW 32.9 0.0 0.0 0.3 33.1 25.8 0.0 0.0 0.0 25.8 30.8 0.0 0.0 0.2 31.0 

Subaru 35.7 0.0 0.0 0.3 36.0 33.3 0.0 0.0 0.0 33.3 34.2 0.0 0.0 0.1 34.4 

Daimler 30.2 0.1 1.2 0.2 31.7 24.4 0.0 1.2 0.0 25.5 28.2 0.1 1.2 0.1 29.5 

Mazda 38.9 0.0 0.0 0.5 39.4 30.4 0.0 0.0 0.0 30.4 36.1 0.0 0.0 0.3 36.4 

* Hyundai and Kia are not included in the table above due to a continuing investigation. On November 2, 2012, EPA announced that Hyundai 

and Kia would lower their fuel economy estimates for many vehicle models as the result of an EPA investigation of test data. 

** EPA calculates the CAFE value for each manufacturer and provides to NHTSA per EPCA. NHTSA publishes the final CAFE values in its annual 

“Summary of Fuel Economy Performance” reports at nhtsa.dot.gov/fuel-economy. 

118 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional Database and Report 

Details 

This section addresses several Trends database topics in greater detail. While the key parameters of the Trends 

database that are of the most importance to users were highlighted in Section 1, this section will help those 

readers who want to further understand how the database is developed and various nuances associated with the 

database. 

A. SOURCES OF INPUT DATA 

Nearly all of the recent model year input for the Trends database is extracted from EPA's 

current vehicle compliance information system, VERIFY, into which automakers submit data 

required by congressional statute and EPA regulations. Prior to the beginning of each model 

year, 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. Automakers report pre-model year vehicle production projections for individual 

models to EPA in the General Label submissions; these projections are considered by EPA and 

automakers to be confidential business information. A few months after the end of each 

model year, automakers submit Final GHG/CAFE data, which EPA and NHTSA use to 

determine compliance with GHG emissions and CAFE standards. These end-of-the-year 

submissions include final production volumes. The production volume levels automakers 

provide in their Final CAFE reports may differ slightly from their Final GHG reports (less 

than 0.1%) because the EPA emissions certification regulations, including GHG 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. To maintain consistency with previous versions of this report, the 

Trends database will continue to use the production volumes for CAFE reporting. Both the 

General Label and Final GHG/CAFE data submissions contain a broad amount of data 

associated with CO2 emissions and fuel economy, vehicle and engine technology, and vehicle 

performance metrics. The Trends database extracts only a portion of the data in the VERIFY 

database. 

This report reflects data from VERIFY as of June 2014. Through MY 2013, all Trends data is 

considered final since it is based on the Final GHG/CAFE compliance reports. For MY 2014, 

all Trends data is preliminary since it is based on confidential pre-model year production 

projections. Final MY 2014 values will be published in next year's report. See Section 10.G 

below for a historical comparison of preliminary and final values. 

While nearly the entire Trends database comes from formal automaker submissions, it also 

contains a small amount of data from external sources. For example, label fuel economy data 

for Sections 7 and 8 are from fueleconomy.gov. As another example, we rely on published 

119 
 

 

 

 

 

 

 

 

 

data from external sources for certain parameters of pre-MY 2011 vehicles, which are not 

universally available through automaker submissions: (1) engines with variable valve timing 

(VVT); (2) engines with cylinder deactivation; and (3) vehicle footprint, which is the product 

of wheelbase times average track width and upon which CO2 emissions and CAFE standards 

are based. Beginning with MY 2011, automaker submissions have included data on these 

parameters. Finally, vehicle 0-to-60 acceleration values are not provided by automakers, but 

rather are calculated from other Trends data as discussed in Section 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 makes the 

assumption that the distance term in all mpg values is fixed, i.e., that for purposes of 

calculating a harmonically averaged fuel economy value, it is assumed that the distance term 

(representing miles travelled) is equivalent across various vehicle fuel economies. This 

assumption is the standard practice with harmonic averaging of multiple fuel economy values 

(including, for example, in calculations for CAFE standards compliance), and simplifies the 

calculations involved. 

Mathematically, when assuming a fixed distance term as discussed above, harmonic averaging 

of multiple fuel economy values can be defined as the inverse of the average of the reciprocals 

of the individual fuel economy values. It is best illustrated by a simple example. 

Consider a round trip of 600 miles. For the first 300-mile leg, the driver is alone, with no 

other passengers or cargo, and, aided by a tailwind, uses 10 gallons of gasoline, for a fuel 

economy of 30 mpg. On the return 300-mile trip, with several passengers, some luggage, and a 

headwind, the driver uses 15 gallons of gasoline, for a fuel economy of 20 mpg. Many people 

will assume that the average fuel economy for the entire 600-mile trip is 25 mpg, the 

arithmetic (or simple) average of 30 mpg and 20 mpg. But, since the driver consumed 10 + 15 

= 25 gallons of fuel during the trip, the actual fuel economy is 600 miles divided by 25 gallons, 

or 24 mpg. 

Why is the actual 24 mpg less than the simple average of 25 mpg? Because the driver used 

more gallons while (s)he was getting 20 mpg than when (s)he was getting 30 mpg. 

This same principle is often demonstrated in elementary school mathematics when an airplane 

makes a round trip, with a speed of 400 mph one way and 500 mph the other way. The 

average speed of 444 mph is less than 450 mph because the airplane spent more time going 

400 mph than it did going 500 mph. 

As in both of the examples above, a harmonic average will typically yield a result that is slightly 

120 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

lower than the arithmetic average. 

The following equation illustrates the use of harmonic averaging to obtain the correct 

mathematical result for the fuel economy example above: 

2

Average mpg = = 24 mpg 

ቀ 1 

30 + 1 

20ቁ

The above example was for a single vehicle with two different fuel economies over two legs of a 

single round trip. But, the same mathematical principle holds for averaging the fuel 

economies of any number of vehicles. For example, the average fuel economy for a set of 10 

vehicles, with three 30 mpg vehicles, four 25 mpg vehicles, and three 20 mpg vehicles would 

be (note that, in order to maintain the concept of averaging, the total number of vehicles in 

the numerator of the equation must equal the sum of the individual numerators in the 

denominator of the equation): 

10 

Average mpg = = 24.4 mpg 

ቀ 3 

30 + 4 20ቁ 25 + 3 

Note that arithmetic averaging, not harmonic averaging, provides the correct mathematical 

result for averaging fuel consumption values (in gallons per mile, the inverse of fuel economy) 

and CO2 emissions (in grams per mile). In the first, round trip, example above, the first leg 

had a fuel consumption rate of 10 gallons over 300 miles, or 0.03333 gallons per mile. The 

second leg had a fuel consumption of 15 gallons over 300 miles, or 0.05 gallons per mile. 

Arithmetically averaging the two fuel consumption values, i.e., adding them up and dividing 

by two, yields 0.04167 gallons per mile, and the inverse of this is the correct fuel economy 

average of 24 mpg. Arithmetic averaging also works for CO2 emissions values, i.e., the average 

of 200 g/mi and 400 g/mi is 300 g/mi CO2 emissions. 

In summary, fuel economy values must be harmonically averaged to maintain mathematical 

integrity, while fuel consumption values (in gallons per mile) and CO2 emissions values (in 

grams per mile) can be arithmetically averaged. 

C. ADJUSTED VS. UNADJUSTED, LABORATORY FUEL 

ECONOMY VALUES 

Change in Emphasis from Unadjusted, Laboratory to Adjusted Data Beginning in 2001 

Prior to 2001, EPA’s Trends reports only included unadjusted, laboratory fuel economy 

values, which are used as the basis for compliance with standards and passenger car gas guzzler 

taxes. Beginning in 2001, Trends reports also included adjusted values which are EPA’s best 

estimate of real world fuel economy performance. Now, most of the tables and figures in this 

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report exclusively show adjusted fuel economy (as well as adjusted CO2 emissions) values. 

One important distinction between the adjusted and the unadjusted, laboratory fuel economy 

values is that the methodology for determining the former has evolved over time to better 

reflect real world performance (see the next sub-section for more details). Some of the changes 

to the adjusted fuel economy value methodology are intended to account for changes in 

consumer driving behavior over time (e.g., higher speeds, higher acceleration rates, greater use 

of air conditioning). Since adjusted Trends values are intended to represent real world 

performance at any given time, modifications to the adjusted value methodology that reflect 

changes in consumer driving behavior have not been "propagated back" through the historical 

Trends database. We note that this is an exception to our general policy of “propagating 

back” changes throughout the historical Trends database, but in this case doing so would skew 

the historical fuel economy performance data (for example, by assuming that drivers in 1975 

used air conditioning much more frequently, or traveled at higher speeds, than they did). 

On the other hand, the methodology for determining unadjusted, laboratory fuel economy 

values has remained largely unchanged since this series began in the mid-1970s.22 Unadjusted 

values therefore provide an excellent basis with which to compare long-term trends in vehicle 

design, apart from the factors that affect real world performance that are reflected in the 

adjusted values. 

Table 10.1 shows both unadjusted, laboratory and adjusted fuel economy values, for the 

overall new car and truck fleet for MY 1975-2014, for city, highway, and combined 

city/highway. It also shows how the ratio of adjusted-to-unadjusted fuel economy has changed 

over time, reflecting that the methodology for adjusted fuel economy values has evolved, while 

the methodology for unadjusted fuel economy values has not changed. 

In addition to Table 10.1, the following tables also include unadjusted, laboratory fuel 

economy values: Tables 2.3, 4.4, 9.1, 9.2, 10.2, and 10.4. 

22 There were some relatively minor test procedure changes made in the late 1970s that, in the aggregate, made the city and highway tests 

slightly more demanding, i.e., the unadjusted fuel economy values for a given car after these test procedure changes were made are 

slightly lower relative to prior to the changes. EPA has long provided CAFE “test procedure adjustments” (TPAs) for passenger cars in 

recognition of the fact that the original CAFE standards were based on the EPA test procedures in place in 1975 (there are no TPAs for light 

trucks). The resulting impacts on the long-term unadjusted fuel economy trends are very small. As shown in Table 9.2, the TPAs for cars 

vary, and 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. 

122 
 

Table 10.1 

Unadjusted, Laboratory and Adjusted Fuel Economy (MPG) for MY 1975 - 2014, Cars and Trucks 

Model 

Year 

Unadjusted 

City (MPG) 

Unadjusted 

Highway 

(MPG) 

Unadjusted 

Combined 

(55/45) 

(MPG) 

Adjusted 

City 

(MPG) 

Adjusted 

Highway 

(MPG) 

Adjusted 

Combined 

(43/57) 

(MPG) 

Ratio of 

Adjusted 

Combined to 

Unadjusted 

Combined 

1975 13.4 18.7 15.3 12.0 14.6 13.1 85.2% 

1976 14.6 20.2 16.7 13.2 15.7 14.2 85.1% 

1977 15.6 21.3 17.7 14.0 16.6 15.1 85.1% 

1978 16.3 22.5 18.6 14.7 17.5 15.8 85.1% 

1979 16.5 22.3 18.7 14.9 17.4 15.9 85.1% 

1980 19.6 27.5 22.5 17.6 21.5 19.2 85.2% 

1981 20.9 29.5 24.1 18.8 23.0 20.5 85.2% 

1982 21.3 30.7 24.7 19.2 23.9 21.1 85.2% 

1983 21.2 30.6 24.6 19.0 23.9 21.0 85.3% 

1984 21.2 30.8 24.6 19.1 24.0 21.0 85.3% 

1985 21.5 31.3 25.0 19.3 24.4 21.3 85.3% 

1986 22.1 32.2 25.7 19.8 25.0 21.8 85.0% 

1987 22.2 32.6 25.9 19.8 25.3 22.0 84.7% 

1988 22.1 32.7 25.9 19.6 25.2 21.9 84.4% 

1989 21.7 32.3 25.4 19.1 24.8 21.4 84.2% 

1990 21.4 32.2 25.2 18.7 24.6 21.2 83.9% 

1991 21.6 32.5 25.4 18.8 24.7 21.3 83.6% 

1992 21.0 32.1 24.9 18.2 24.4 20.8 83.4% 

1993 21.2 32.4 25.1 18.2 24.4 20.9 83.1% 

1994 20.8 31.6 24.6 17.8 23.8 20.4 82.9% 

1995 20.8 32.1 24.7 17.7 24.1 20.5 82.7% 

1996 20.8 32.2 24.8 17.6 24.0 20.4 82.4% 

1997 20.6 31.8 24.5 17.4 23.6 20.2 82.2% 

1998 20.6 31.9 24.5 17.2 23.6 20.1 81.9% 

1999 20.3 31.2 24.1 16.9 23.0 19.7 81.7% 

2000 20.5 31.4 24.3 16.9 23.0 19.8 81.3% 

2001 20.5 31.1 24.2 16.8 22.8 19.6 81.0% 

2002 20.4 30.9 24.1 16.6 22.5 19.5 80.7% 

2003 20.6 31.3 24.3 16.7 22.7 19.6 80.4% 

2004 20.2 31.0 24.0 16.3 22.4 19.3 80.2% 

2005 21.0 32.1 24.8 16.8 23.1 19.9 79.8% 

2006 21.2 32.6 25.2 17.0 23.4 20.1 79.8% 

2007 21.8 33.4 25.8 17.4 24.0 20.6 79.6% 

2008 22.1 34.0 26.3 17.7 24.4 21.0 79.5% 

2009 23.8 36.4 28.2 18.9 26.0 22.4 79.1% 

2010 24.1 36.6 28.4 19.1 26.2 22.6 79.0% 

2011 23.6 36.4 28.1 18.8 26.1 22.4 79.4% 

2012 25.1 38.6 29.8 19.9 27.6 23.6 78.9% 

2013 25.8 39.5 30.5 20.3 28.1 24.1 78.6% 

2014 25.8 39.7 30.6 20.4 28.3 24.2 78.7% 

123 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Methodological Approaches for Adjusted Fuel Economy Values 

EPA has improved its methodology for estimating adjusted (or real world) fuel economy (and 

CO2 emissions) performance over time. EPA’s last methodological revisions for how we 

calculate city, highway, and combined fuel economy label estimates for cars and light-duty 

trucks were established in a December 2006 rulemaking (EPA 2006, 77872). 

This current methodology incorporates equations that directly account for several important 

factors that affect fuel economy performance in the real world, such as high speeds, aggressive 

accelerations and decelerations, the use of air conditioning, and operation in cold 

temperatures, and indirectly account (through the use of a 9.5% universal downward 

adjustment factor) for a number of other factors that are not reflected in EPA laboratory test 

data such as changing fuel composition, wind, road conditions, etc. While some of these 

factors may not have changed (or may not have changed much) over time and therefore new 

estimation methods that account for these factors could be "propagated back" throughout the 

historical Trends database, we believe that many of the factors have changed significantly over 

time (e.g., highway speeds, acceleration rates, use of air conditioning), and therefore new 

estimation methods could not be fully "propagated back" through the historical Trends 

database without impacting the integrity of the historical database with respect to real world 

fuel economy performance. 

There are two important consequences of this approach for users of this report. First, every 

adjusted fuel economy value in this report for 1986 and later model years is lower than shown 

in pre-2007 reports. Second, we employed unique approaches for generating adjusted fuel 

economy values in the historical Trends database for three distinct time frames. The following 

discussion will first address the MY 1975-1985 time frame, then the MY 2005-2014 time 

frame, and then, finally, the approach for the MY 1986-2004 time frame that represents a 

"phased-in" approach between the 1975-1985 time frame and the 2005-2014 time frame. 

For the MY 1975-1985 time frame, the adjusted fuel economy values in the Trends database 

are calculated using the methodology adopted by EPA in an April 1984 rulemaking that 

established universal fuel economy label adjustment factors of 0.9 for city fuel economy and 

0.78 for highway fuel economy that took effect for MY 1985 vehicles (EPA 1984). Accordingly, 

for MY 1975-1985, adjusted city fuel economy is equal to 0.9 times the unadjusted, laboratory 

city fuel economy value, and adjusted highway fuel economy is 0.78 times the unadjusted, 

laboratory highway fuel economy. A single, combined adjusted fuel economy value is based on 

a 55% city/45% highway weighting factor. We believe that these adjustment factors are 

appropriate for new vehicles through the 1985 model year. 

For the MY 2005-2014 time frame, the adjusted city and highway values in the Trends 

database for vehicles that undergo full "5-cycle" fuel economy testing (Federal Test Procedure 

for urban stop-and-go driving, Highway Fuel Economy Test for rural driving, US06 test for 

high speeds and aggressive driving, SC03 test for air conditioning operation, and cold FTP test 

for cold temperature operation) are calculated by weighting the 5-cycle test data according to 

124 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the "composite" 5-cycle equations (EPA 2006, 77883-77886). The combined city/highway 

adjusted fuel economy value for these vehicles is based on a 43% city/57% highway weighting. 

In MY 2014, about 13% of all vehicle fuel economy data were generated from the full 5-cycle 

test protocol. 

It is important to emphasize that the 43% city/57% highway weighting used for adjusted 5-

cycle fuel economy values beginning in MY 2005 is different from the 55% city/45% highway 

weighting used to generate adjusted fuel economy values for MY 1975-1985 in the Trends 

database. 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 (EPA 2006, 77904). Based on this speed 

cutpoint, the correct weighting for correlating the new city and highway fuel economy values 

with real world driving, on a miles driven basis, is 43% city/57% highway, and therefore this 

weighting is necessary in order to maintain the integrity of projections of fleetwide fuel 

economy performance based on Trends data. The 55% city/45% highway weighting is still 

used for both Fuel Economy and Environment Labels and the CAFE and GHG emissions 

compliance programs. 

Most current vehicles do not undergo full 5-cycle testing; instead manufacturers derive 5-cycle 

values from 2-cycle fuel economy test results (EPA Federal Test Procedure and Highway Fuel 

Economy Test) based on the relationship between 2-cycle and 5-cycle fuel economy data for 

the industry as a whole. Beginning with MY 2011, manufacturers are required to evaluate 

whether the fuel economy estimates for certification vehicles from 5-cycle tests are comparable 

to results from the less resource-intensive “derived 5-cycle” method. If the results are 

comparable, manufacturers can use the derived 5-cycle method for all vehicle models 

represented by the certification vehicle. If the full 5-cycle method yields significantly lower fuel 

economy estimates than the derived 5-cycle method, then the manufacturer must use the full 

5-cycle method for all models represented by the certification vehicle. 

For vehicles that can use the derived 5-cycle method, the following equations are used to 

convert unadjusted, laboratory fuel economy values for city and highway to adjusted fuel 

economy values. 

1

ADJ CITY = 1.1805 ቀ0.003259 + LAB CITYቁ

1

ADJ HWY = 1.3466 ቀ0.001376 + LAB HWYቁ

As above, these values are weighted 43% city/57% highway in order to calculate a single, 

adjusted combined fuel economy value. 

For more details on the specific equations that allow an automaker to calculate new label 

125 
 

 

 

 

 

 

 

 

 

 

 

values using either the vehicle-specific 5-cycle test data or the derived 5-cycle approach, and the 

impact of these changes on average fuel economy label values, see the preamble to the 2006 

regulations (EPA 2006). 

How much of a difference, on average, are the fuel economy values based on the derived 5-

cycle method from the values based on the universal adjustment factors for MY 1975-1985? 

These derived 5-cycle method values are lower than values based on the universal adjustment 

factors for MY 1975-1985, and the differences are greater for higher fuel economy vehicles 

than for lower fuel economy vehicles. For example, compared to the use of the universal 

adjustment factors for MY 1975-1985, a 15 mpg city value will be reduced by an additional 

10%, while a 50 mpg city value will be reduced by an additional 18%. Likewise, a 20 mpg 

highway value will be reduced by an additional 7%, while a 50 mpg highway value will be 

reduced by an additional 11%. In the 2006 rulemaking, EPA projected an overall average 

fleetwide adjustment of 11% lower for city fuel economy and 8% lower for highway fuel 

economy, beyond that in the older label adjustment methodology. The appropriate fleetwide 

factors to convert adjusted MY 1975-1985 fuel economy values to the adjusted derived 5-cycle, 

43% city/57% highway weighting, fuel economy values are dependent on the city fuel 

economy-to-highway fuel economy ratios in the fleet. On average, for the current fleet, 

combining the 11% lower adjustment for city fuel economy, the 8% lower adjustment for 

highway fuel economy, and the shift to the 43% city/57% highway weighting, the combined 

city/highway fuel economy values are 7% lower than those based on the older label 

adjustment methodology. This 7% lower value is the average impact for a fleet with the mpg 

and city fuel economy-to-highway fuel economy characteristics of the current fleet, and would 

not be the appropriate value for individual models, partial fleet segments, or for past or future 

fleets with different mpg and city fuel economy-to-highway fuel economy distributions. 

Finally, manufacturers have the option of voluntarily using lower fuel economy label estimates 

than those resulting from the full 5-cycle or derived 5-cycle approaches discussed above. In the 

rare cases where automakers choose to do so, we base adjusted values on these voluntary lower 

fuel economy labels, again using the 43% city/57% highway weighting. 

For the MY 1986-2004 time frame, we calculated adjusted fuel economy values based on the 

simplifying assumption that the impacts of the factors that have led to lower real world fuel 

economy, as outlined in the 2006 rulemaking and discussed above, have occurred in a gradual 

(i.e., linear) manner over the 20 years from 1986 through 2005. 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 horsepowerto-weight ratios, suburbanization, congestion, greater use of air conditioning, gasoline 

composition, et al) that have affected real world fuel economy since 1985 have changed over 

time. We simply assumed 1/20 of the fully phased-in downward adjustment for city and 

highway values would be reflected in the 1986 data, 2/20 of this adjustment would be 

reflected in the 1987 data, etc., up to 19/20 of this adjustment in 2004 and the full 

adjustment in 2005 and later years. Likewise, EPA has assumed the 55/45 city/highway 

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weighting changes to a 43/57 city/highway weighting in a linear fashion over the 1986 to 

2005 time period as well. 

One consequence of the approach used in this report is that there are, in effect, 21 different 

sets of numerical adjustments for determining adjusted fuel economy values: a constant 

numerical adjustment for MY 1975-1985, unique numerical adjustments for each of the 19 

model years from 1986 through 2004, and a constant numerical adjustment for MY 2005-

2014. Due in part to this, the ratio of the adjusted-to-unadjusted fuel economy values have 

been changing over time. As shown in Table 10.1, the adjusted-to-unadjusted fuel economy 

ratio was around 0.85 for MY 1975-1985 data, and decreased during the phase-in period from 

MY 1986-2004, and has been approximately 0.80 since MY 2005. The ratio is 0.79 in MY 

2013, and is projected to remain at 0.79 in MY 2014. Even though the basic methodology for 

determining adjusted fuel economy values is now fixed, it is possible that the adjusted-tounadjusted fuel economy ratio may change in the future. Any changes in this ratio would be 

due to the fact that the current adjusted fuel economy methodology now incorporates tests 

unique to the adjusted methodology and is no longer strictly calculated from the laboratory 

fuel economy results. On the one hand, all other things being equal, use of the derived 5-cycle 

equations would be expected to lower this ratio over time since, as discussed earlier, the 

equations apply a greater percentage reduction to high fuel economy values than to low fuel 

economy values (this has, in fact, led to a slight reduction in the ratio since 2005). On the 

other hand, it is also possible that vehicle powertrain designs may be more robust in the future 

with respect to a broader set of in-use driving conditions, and given that the 5-cycle 

methodology is data driven, it is impossible to predict the direction of changes in the adjustedto-unadjusted fuel economy ratio in the future. This report will continue to monitor this datadriven adjusted-to-unadjusted fuel economy ratio. 

One Illustrative Example of Multiple Fuel Economy Metrics and Values 

One potentially confusing element of any discussion of historical fuel economy values is the 

various metrics by which fuel economy can be expressed. As an illustration to help the reader 

understand the various fuel economy values that can be associated with an individual vehicle, 

Table 10.2 shows four different ways to express the fuel economy of the MY 2005 Honda 

Insight. 

Unadjusted, laboratory city and highway fuel economy values are direct fuel economy 

measurements from the formal EPA 2-cycle city (Federal Test Procedure, or urban commute) 

and highway laboratory tests. These values form the basis for automaker compliance with 

CAFE standards, and are harmonically averaged, and weighted 55% city and 45% highway, to 

generate a combined value. The 2005 Honda Insight had an unadjusted city value of 68 mpg, 

an unadjusted highway value of 84 mpg, and an unadjusted combined value of 74 mpg. 

At the time, the MY 2005 Honda Insight had an original city label value of 61 mpg, which was 

calculated by multiplying its unadjusted city test value of 68 mpg by 0.9. Likewise, its original 

highway value was 66 mpg, calculated by multiplying its unadjusted highway test value of 84 

127 
 

 

 

 

 

 

 

 

mpg by 0.78. Harmonically averaging these values, with a 55% city/45% highway weighting, 

led to a combined original MY 2005 label value of 63 mpg. 

Today, as a used car, the 2005 Honda Insight would have lower label values based on the 5-

cycle method (reflecting, in addition to 2-cycle urban commuting and rural highway operation, 

additional conditions such as high speed/high acceleration, high temperature/air 

conditioning, and cold temperature operation) for determining city and highway values, first 

implemented in MY 2008, and discussed in the previous sub-section. For the 2005 Insight, 

the 5-cycle method yields a city label value of 48 mpg and a highway value of 58 mpg. Today’s 

labels continue to use a 55% city/45% highway weighting, and the harmonically averaged, 

55% city/45% highway weighted, combined value for the 2005 Insight is 52 mpg. These 

current label values, based on the 5-cycle methodology, are considerably lower than the 

original label values. 

Finally, for the MY 2005 Honda Insight, this Trends report uses the adjusted fuel economy 

methodology discussed in the previous sub-section, that is used in the Trends report for all 

vehicles beginning in MY 2005. The adjusted Trends city and highway values are the same as 

those for the current label, since both the current label and the adjusted Trends approach use 

the same 5-cycle methodology. But, the adjusted Trends approach uses a city/highway 

weighting of 43% city/57% highway to best correlate with the driving activity studies 

underlying the 5-cycle methodology. This different city/highway weighting leads to a 53 mpg 

combined value, slightly higher than the 52 mpg combined value for the current label. 

Table 10.2 

Four Different Fuel Economy Metrics for the MY 2005 Honda Insight 

Fuel Economy Metric 

Fuel Economy Value (MPG) 

Comb City Hwy Basis 

City/Highway 

Weighting 

Unadjusted, Laboratory 

Original MY 2005 Label 

Current Label 

Current Adjusted Trends 

74 68 84 

63 61 66 

52 48 58 

53 48 58 

Unadjusted 2-cycle city and highway test values 

City test x 0.9 

Highway test x 0.78 

Adjusted 5-cycle methodology 

Adjusted 5-cycle methodology 

55%/45% 

55%/45% 

55%/45% 

43%/57% 

128
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D. VEHICLE TAILPIPE CO2 EMISSIONS DATA 

CO2 emissions data were added to the entire historical Trends database beginning with the 

2009 report. All CO2 emissions values in this report are calculated from corresponding fuel 

economy values using the fuel-specific emissions factors described below. Accordingly, the 

adjusted and unadjusted, laboratory CO2 emissions values in this report reflect the 

methodological approaches underlying the adjusted and unadjusted, laboratory fuel economy 

values that were discussed in detail in the previous section. 

While CO2 emissions data is included in several key summary tables and figures in the report, 

there are many other tables and figures that present fuel economy values but not CO2 

emissions values. This section provides a simple method that a reader can use to estimate CO2 

emissions values from any fuel economy value in the report. 

If a fuel economy value is given for a single gasoline vehicle, or a 100% gasoline vehicle fleet, 

one can calculate the corresponding CO2 emissions value by simply dividing 8887 (which is a 

typical value for the grams of CO2 per gallon of gasoline test fuel, assuming all the carbon is 

converted to CO2) by the fuel economy value in miles per gallon. For example, 8887 divided 

by a gasoline vehicle fuel economy of 30 mpg would yield an equivalent CO2 emissions value 

of 296 grams per mile. This is the methodology used to generate the CO2 emissions values for 

all of the gasoline vehicles in the Trends database. 

Since gasoline vehicle production has accounted for 99+% of all light-duty vehicle production 

for most of the model years since 1975, this simple approach yields very accurate results for 

most model years. 

Diesel fuel has 14.5% higher carbon content per gallon than gasoline. To calculate a CO2 

equivalent value for a diesel vehicle, one should divide 10,180 by the diesel vehicle fuel 

economy value. Accordingly, a 30 mpg diesel vehicle would have a CO2 equivalent value of 

339 grams per mile. This is the methodology used to generate the CO2 emissions values for 

the relatively small number of diesel vehicles in the Trends database. 

To make the most accurate conversions of industry-wide fuel economy values to CO2 

emissions values, readers should divide model year-specific industry-wide values for grams of 

CO2 per gallon in Table 10.3, which are based on actual light-duty gasoline and diesel vehicle 

production in that year, by industry-wide fuel economy values in miles per gallon. 

Readers must make judgment calls about how to best convert fuel economy values that do not 

represent industry-wide values (e.g., just cars or vehicles with 5-speed automatic transmissions). 

If the user knows the gasoline/diesel production volume fractions for the vehicles of interest, 

it is best to generate a weighted value of grams of CO2 per gallon based on the 8887 (gasoline) 

and 10,180 (diesel) factors discussed above. Otherwise, the reader can choose between the 

model year-specific CO2 emissions per gallon weightings in Table 10.3 (which implicitly 

assume that the diesel fraction for the vehicles of interest is similar to that for the overall fleet 

129 
 

 

 

in that year) or the gasoline value of 8887 (implicitly assuming no diesels in that database 

component). In nearly all cases, any error associated with either of these approaches will be 

negligible. 

Table 10.3 

Factors for Converting Industry-Wide Fuel Economy Values from this Report to Carbon Dioxide 

Emissions Values 

Gasoline Diesel Weighted CO2 

Production Production per Gallon 

Model Year Share Share (grams) 

1975 99.8% 0.2% 8890 

1976 99.8% 0.2% 8890 

1977 99.6% 0.4% 8892 

1978 99.1% 0.9% 8899 

1979 98.0% 2.0% 8913 

1980 95.7% 4.3% 8943 

1981 94.1% 5.9% 8963 

1982 94.4% 5.6% 8959 

1983 97.3% 2.7% 8922 

1984 98.2% 1.8% 8910 

1985 99.1% 0.9% 8899 

1986 99.6% 0.4% 8892 

1987 99.7% 0.3% 8891 

1988 99.9% 0.1% 8888 

1989 99.9% 0.1% 8888 

1990 99.9% 0.1% 8888 

1991 99.9% 0.1% 8888 

1992 99.9% 0.1% 8888 

1993 100.0% - 8887 

1994 100.0% 0.0% 8887 

1995 100.0% 0.0% 8887 

1996 99.9% 0.1% 8888 

1997 99.9% 0.1% 8888 

1998 99.9% 0.1% 8888 

1999 99.9% 0.1% 8888 

2000 99.9% 0.1% 8888 

2001 99.9% 0.1% 8888 

2002 99.8% 0.2% 8890 

2003 99.8% 0.2% 8890 

2004 99.9% 0.1% 8888 

2005 99.7% 0.3% 8891 

2006 99.6% 0.4% 8892 

2007 99.9% 0.1% 8888 

2008 99.9% 0.1% 8888 

2009 99.5% 0.5% 8893 

2010 99.3% 0.7% 8896 

2011 99.2% 0.8% 8897 

2012 99.1% 0.9% 8899 

2013 99.1% 0.9% 8899 

2014 98.5% 1.5% 8907 

130
 
 

 

 

 

 

 

 

 

 

 

 

 

 

E. VEHICLE-RELATED GHG EMISSIONS SOURCES OTHER 

THAN TAILPIPE CO2 EMISSIONS 

The CO2 emissions data in this report reflect the sum of the vehicle tailpipe emissions of CO2, 

carbon monoxide, and hydrocarbons, with the latter two converted to equivalent CO2 levels 

on a mass basis. While carbon monoxide and hydrocarbon emissions add, on average, less 

than one percent to overall CO2 tailpipe emissions values, these compounds are included in 

the tailpipe CO2 emissions data because they are converted to CO2 relatively quickly in the 

atmosphere, and to maintain consistency with greenhouse gas (GHG) emissions standards 

compliance. EPA regulations refer to this sum as “carbon related exhaust emissions” or 

CREE, but we use the term CO2 emissions in this report for simplicity. 

It is important to emphasize that tailpipe CO2 emissions do not represent the entire GHG 

burden associated with a personal vehicle, and there are at least six other vehicle-related GHG 

sources. While this report cannot provide authoritative data for each of these other vehiclerelated GHG sources, they will be briefly identified and discussed below for context, with an 

emphasis on the approximate magnitude of each source relative to the magnitude of the 

tailpipe CO2 emissions that are documented in this report. 

Tailpipe emissions of nitrous oxide (N2O) 

Nitrous oxide is a greenhouse gas and a constituent in the exhaust from internal combustion 

engines. It is emitted from gasoline and diesel vehicles during specific catalytic converter 

temperature conditions conducive to its formation. EPA does not currently require N2O 

emissions measurement as a part of the formal EPA vehicle certification process (it will begin 

to be required in the MY 2017-2019 timeframe), so we only have limited test data at this time. 

Based on this limited data, EPA estimates typical N2O emissions from late model gasoline cars 

to be on the order of 0.005 g/mi (EPA and DOT 2010, 25422). With a global warming 

potential of 298, this yields a CO2-equivalent value of approximately 1.5 g/mi. or about 0.4% 

of the 369 g/mi adjusted fleetwide CO2 emissions value for MY 2013. Under the National 

Program regulations for MY 2012-2025, EPA has established an N2O per-vehicle emissions cap 

of 0.010 g/mi, which is not intended to reduce N2O emissions, but rather to ensure that there 

are no increases in the future (EPA and DOT 2010, 25421). 

Tailpipe emissions of methane (CH4) 

Methane is a greenhouse gas and also a constituent in internal combustion engine exhaust. As 

the simplest hydrocarbon compound (one carbon atom and four hydrogen atoms), it is one of 

the large number of hydrocarbon compounds formed during the imperfect combustion of 

hydrocarbon-based fuels such as gasoline and diesel (and the most prominent hydrocarbon 

compound in compressed natural gas vehicle exhaust). EPA requires that CH4 emissions be 

measured during the formal EPA vehicle certification program. Typical methane emissions 

from late model gasoline cars are about 0.015 g/mi (EPA and DOT 2010, 25423). With a 

131 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

global warming potential of 25, this yields a CO2-equivalent value of approximately 0.4 g/mi, 

or about 0.1% of the 369 g/mi adjusted fleetwide CO2 emissions value for MY 2013. Under 

the National Program regulations for MY 2012-2025, EPA has established a CH4 per-vehicle 

emissions cap of 0.03 g/mi, which is not intended to reduce CH4 emissions, but rather to 

ensure that there are no increases in the future (EPA and DOT 2010, 25421 and EPA and 

DOT 2012, 62770). 

Vehicle GHG emissions associated with air conditioner refrigerants 

Nearly all new personal vehicles in the U.S. are equipped with air conditioners. Until very 

recently, all automotive air conditioners used the refrigerant HFC-134a, which is a very strong 

greenhouse gas with a global warming potency of 1,430. Small amounts of refrigerant leakage 

can occur during everyday operation, during maintenance and servicing, and during ultimate 

disposal. Based on the combination of relatively small mass leakage with the extremely high 

global warming potency, EPA estimates typical HFC-134a CO2-equivalent values of 13.8 g/mi 

for cars and 17.2 g/mi for light trucks, or about 4% of the 369 g/mi adjusted fleetwide CO2 

emissions value for MY 2013 (EPA and DOT 2012, 62805). There are no standards under the 

MY 2012-2015 National Program for the control of air conditioner refrigerant leakage 

emissions, but automakers can earn credits for reducing leakage emissions that can be used to 

help achieve compliance with the tailpipe CO2 emissions standards. Our recent Manufacturer 

Performance Report for MY 2012 showed that automakers generated, on average, about 4 

g/mi CO2-equivalent credit due to reduced air conditioner refrigerant leakage in MY 2012 

(EPA 2014). Beginning with MY 2013, some automakers are beginning to use a new air 

conditioner refrigerant, HFO-1234yf, which has a much lower global warming potency of 4. 

GHG emissions associated with fuel production and distribution 

Motor vehicle fuel production and distribution (often referred to as “upstream” emissions) can 

produce significant GHG emissions. The relative relationship between vehicle tailpipe CO2 

emissions and vehicle fuel-related production/distribution GHG emissions can vary greatly. 

For example, for typical gasoline today, a rule-of-thumb is that gasoline 

production/distribution (all steps including oil production, oil transport, refining, and 

gasoline transport to the service station) yields about 25% of the GHG emissions associated 

with vehicle tailpipe CO2 emissions. Based on this rule-of-thumb, gasoline 

production/distribution-related GHG emissions associated with the 369 g/mi adjusted 

fleetwide CO2 vehicle tailpipe emissions value for MY 2013 would be about 92 g/mi, for a 

total adjusted fleetwide MY 2013 CO2 tailpipe plus gasoline production/distribution GHG 

emissions value of about 461 g/mi. Other fuels currently used in personal vehicles, such as 

diesel from crude oil, ethanol from corn, and compressed natural gas, can also have significant 

fuel production/distribution GHG emissions. However, like gasoline, these GHG emissions 

are typically much smaller than those from the vehicle tailpipe. 

But, of course, some other fuels have very different vehicle tailpipe vs fuel 

production/distribution characteristics. For example, electric vehicles have zero tailpipe 

132 
 

 

 

 

 

 

 

 

 

 

 

 

emissions, and so all GHG emissions associated with electric vehicle operation are associated 

with the generation and distribution of electricity. The same goes for hydrogen. On the other 

hand, carbon-based fuels produced from renewable feedstocks could have similar vehicle 

tailpipe emissions (note there is an accounting issue here, while Trends would assign tailpipe 

emissions to the vehicle, current IPCC rules do not count tailpipe emissions for renewable 

fuels), but “negative” fuel production/distribution-related GHG emissions if little or no fossil 

fuels are used in the production/distribution of the fuel and the “carbon uptake” associated 

with renewable fuels is accounted for at the production/distribution step. 

There is an exhaustive literature on the relative vehicle versus fuel-related GHG emissions for 

various fuel/feedstock combinations, and the reader should consult the literature for detailed 

analyses. 

GHG emissions associated with vehicle manufacturing and assembly 

Some studies estimate that the GHG emissions associated with vehicle and component 

manufacturing and assembly for conventional gasoline vehicles are on the order of 10-15% of 

total life-cycle vehicle GHG emissions (where vehicle tailpipe and fuel production/distribution 

accounts for nearly all of the remaining vehicle life cycle emissions).23 Based on the 

approximate 461 g/mi adjusted fleetwide value calculated above for MY 2013 CO2 tailpipe 

plus gasoline production/distribution GHG emissions, this would imply that typical vehicle 

and component manufacturing and assembly GHG emissions would be on the order of 

approximately 50-80 g/mi. 

GHG emissions associated with vehicle disposal 

The GHG emissions associated with vehicle disposal, or end-of-life, are typically not more than 

a few percent of total life-cycle vehicle emissions for a conventional gasoline vehicle. Based on 

the above approximations, this would imply that GHG emissions associated with vehicle 

disposal might be on the order of 10 g/mi or less. 

F. OTHER DATABASE METHODOLOGY ISSUES 

Changes in Car-Truck Classification Definitions 

Car-truck definitions through the 2010 report were based EPA’s engineering judgment. Until 

recently, EPA and NHTSA had slightly different regulatory definitions for car-truck 

classifications with respect to health-related emissions and fuel economy, respectively, and the 

Trends report followed a third approach, though in practice there was broad (though not 

universal) agreement among the three approaches. 

23 For example, see Samaras, C. and Meisterling, K. Life Cycle Assessment of Greenhouse Gas Emissions from Plug-in Hybrid Vehicles: 

Implications for Policy. Environmental Science & Technology 2008, 42 (9):3170–3176, or Notter, D. et al. Contribution of Li-Ion Batteries to 

the Environmental Impact of Electric Vehicles. Environmental Science & Technology 2010, 44 (17): 6550-6556. 

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Beginning with the 2011 report, Trends car-truck classifications followed current regulatory 

definitions used by both EPA and NHTSA for CO2 emissions and fuel economy standards. 

See definitions for passenger automobiles (cars) and non-passenger automobiles (trucks) later 

in this section. These current definitions differ from those used in older versions of this 

report, and reflect a decision by NHTSA to reclassify many small, 2-wheel drive, sport utility 

vehicles (SUVs) from the truck category to the car category, beginning with MY 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 we did not have all of the requisite technical information on which to make 

retroactive car-truck classifications, we used engineering judgment to classify past models. 

Inclusion of Medium-Duty Passenger Vehicles 

Beginning with the 2011 report, medium-duty passenger vehicles (MDPVs), those SUVs and 

passenger vans (but, not pickup trucks) with gross vehicle weight ratings between 8500 and 

10,000 pounds, are included in the light-duty truck category. This coincided with new 

regulations by NHTSA to treat these vehicles as light-duty, rather than heavy-duty, vehicles 

beginning in MY 2011. This represents a minor change to the database, since the number of 

MDPVs is much smaller than it once was (e.g., only 6500 MDPVs were sold in MY 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 MY 2011. Accordingly, 

this represents a small inflection point for the database--for the overall car and truck fleet in 

MY 2011, the inclusion of MDPVs decreased average adjusted fuel economy by 0.01 mpg and 

increased average adjusted CO2 emissions by 0.3 g/mi, compared to the fleet without MDPVs. 

The impacts on the truck fleet only were about twice as high, but still very small in absolute 

terms. 

G. COMPARISON OF PRELIMINARY AND FINAL FLEETWIDE 

FUEL ECONOMY VALUES 

In recent years, the data for the last model year included in each report has been preliminary 

(i.e., based on projected vehicle production volumes provided by automakers prior to the 

beginning of the model year), while the data for all other model years has been final. This 

leads to the logical question, how accurate have the preliminary projections been? 

Table 10.4 compares the preliminary and final fleetwide fuel economy values for recent years 

(note that the differences for CO2 emissions data would be similar, on a percentage basis). 

For the adjusted fuel economy data, values are only shown beginning in MY 2007, as final 

adjusted values in this report reflect the revised methodology for calculating adjusted fuel 

134 
 

 

 

 

 

economy values beginning with the 2007 report and therefore the comparable preliminary 

values prior to MY 2007 would not reflect an apples-to-apples comparison. Since MY 2007, 

the final adjusted fuel economy values have typically been a little higher than the preliminary 

adjusted fuel economy values. The major exceptions have been MY 2009, when the final value 

was 1.3 mpg higher, and MY 2011, when the final value was 0.4 mpg lower. 

Comparative unadjusted fuel economy data are shown back to MY 2000. For a majority of 

the years, the final unadjusted fuel economy values have been higher than the preliminary fuel 

economy values, and typically the final value is within 0.5 mpg of the preliminary value. As 

with the adjusted data, the biggest outlier was MY 2009, when the final unadjusted value was 

1.8 mpg higher than the preliminary value. There was considerable market turmoil in MY 

2009 driven by the economic recession. 

Table 10.4 

Comparison of Preliminary and Final Fuel Economy Values, Both Cars and Trucks 

Model Year 

Adjusted Fuel Economy (MPG) Unadjusted Fuel Economy (MPG) 

Preliminary 

Value 

Final 

Value 

Final Minus 

Preliminary 

Preliminary 

Value 

Final 

Value 

Final Minus 

Preliminary 

2000 - - - 24.0 24.3 +0.3 

2001 - - - 23.9 24.2 +0.3 

2002 - - - 24.0 24.1 +0.1 

2003 - - - 24.4 24.3 -0.1 

2004 - - - 24.4 24.0 -0.4 

2005 - - - 24.6 24.8 +0.2 

2006 - - - 24.6 25.2 +0.6 

2007 20.2 20.6 +0.4 25.3 25.8 +0.5 

2008 20.8 21.0 +0.2 26.0 26.3 +0.3 

2009 21.1 22.4 +1.3 26.4 28.2 +1.8 

2010 22.5 22.6 +0.1 28.3 28.4 +0.1 

2011 22.8 22.4 -0.4 28.6 28.1 -0.5 

2012 23.8 23.6 -0.2 30.0 29.8 -0.2 

2013 24.0 24.1 +0.1 30.3 30.5 +0.2 

2014 24.2 - 30.6 -

135
 
 

 

 

 

 

 

 

 

 

H. DEFINITIONS AND ACRONYMS 

Electric vehicle (EV) means a motor vehicle that is powered solely by an electric motor drawing 

current from a rechargeable energy storage system, such as from storage batteries or other 

portable electrical energy storage devices. For the Trends report, electric vehicles do not 

generally include fuel cell vehicles. 

Flexible fuel vehicle (FFV) means any motor vehicle engineered and designed to be operated 

on a petroleum fuel and on a methanol or ethanol fuel, or any mixture of the petroleum fuel 

and methanol or ethanol. Methanol-fueled and ethanol-fueled vehicles that are only marginally 

functional when using gasoline ( e.g., the engine has a drop in rated horsepower of more than 

80 percent) are not flexible fuel vehicles. 

Footprint means the product of average track width (rounded to the nearest tenth of an inch) 

and wheelbase (measured in inches and rounded to the nearest tenth of an inch), divided by 

144 and then rounded to the nearest tenth of a square foot, where the average track width is 

the average of the front and rear track widths, where each is measured in inches and rounded 

to the nearest tenth of an inch. 

Fuel cell vehicle (FCV) means an electric vehicle propelled solely by an electric motor where 

energy for the motor is supplied by an electrochemical cell that produces electricity via the 

non-combustion reaction of a consumable fuel, typically hydrogen. 

Gasoline gallon equivalent means an amount of electricity or fuel with the energy equivalence 

of one gallon of gasoline. For purposes of the Trends report, one gallon of gasoline is 

equivalent to 33.705 kilowatt-hours of electricity or 121.5 standard cubic feet of natural gas. 

Hybrid electric vehicle (HEV) means a motor vehicle which draws propulsion energy from 

onboard sources of stored energy that are both an internal combustion engine or heat engine 

using consumable fuel, and a rechargeable energy storage system such as a battery, capacitor, 

hydraulic accumulator, or flywheel, where recharge energy for the energy storage system comes 

solely from sources on board the vehicle. 

Light Truck means an automobile that is not a car or a work truck and includes vehicles 

described in paragraphs (a) and (b) below: 

(a) An automobile designed to perform at least one of the following functions: 

(1) Transport more than 10 persons; 

(2) Provide temporary living quarters; 

(3) Transport property on an open bed; 

(4) Provide, as sold to the first retail purchaser, greater cargo-carrying than passengercarrying volume, such as in a cargo van; if a vehicle is sold with a second-row seat, its 

cargo-carrying volume is determined with that seat installed, regardless of whether the 

manufacturer has described that seat as optional; or 

(5) Permit expanded use of the automobile for cargo-carrying purposes or other 

nonpassenger-carrying purposes through: 

136 
 

 

 

 

 

 

 

 

 

 

 

(i) For non-passenger automobiles manufactured in model year 2008 and beyond, 

for vehicles equipped with at least 3 rows of designated seating positions as 

standard equipment, permit expanded use of the automobile for cargo-carrying 

purposes or other nonpassenger-carrying purposes through the removal or stowing 

of foldable or pivoting seats so as to create a flat, leveled cargo surface extending 

from the forwardmost point of installation of those seats to the rear of the 

automobile's interior. 

(b) An automobile capable of off-highway operation, as indicated by the fact that it: 

(1)(i) Has 4-wheel drive; or 

(ii) Is rated at more than 6000 pounds gross vehicle weight; and 

(2) Has at least four of the following characteristics calculated when the automobile is 

at curb weight, on a level surface, with the front wheels parallel to the automobile's 

longitudinal centerline, and the tires inflated to the manufacturer's recommended 

pressure— 

(i) Approach angle of not less than 28 degrees. 

(ii) Breakover angle of not less than 14 degrees. 

(iii) Departure angle of not less than 20 degrees. 

(iv) Running clearance of not less than 20 centimeters. 

(v) Front and rear axle clearances of not less than 18 centimeters each. 

*Please see Section 10.F for Changes in Car-Truck Classification Definitions over time. 

Minivan means a light truck which is designed primarily to carry no more than eight 

passengers, having an integral enclosure fully enclosing the driver, passenger, and load-carrying 

compartments, and rear seats readily removed, folded, stowed, or pivoted to facilitate cargo 

carrying. A minivan typically includes one or more sliding doors and a rear liftgate. Minivans 

typically have less total interior volume or overall height than full sized vans and are commonly 

advertised and marketed as “minivans.” 

Mpg means miles per gallon. 

Mpge means miles per gasoline gallon equivalent (see gasoline gallon equivalent above). 

Pickup truck means a light truck which has a passenger compartment and an open cargo bed. 

Plug-in hybrid electric vehicle (PHEV) means a hybrid electric vehicle that has the capability to 

charge the battery from an off-vehicle electric source, such that the off-vehicle source cannot be 

connected to the vehicle while the vehicle is in motion. 

Special purpose vehicles means automobiles with GVWR less than or equal to 8,500 pounds 

and medium-duty passenger vehicles which possess special features and which the 

Administrator determines are more appropriately classified separately from typical 

automobiles. 

*For purposes of the Trends report, we used engineering judgment to allocate the very small number of 

vehicles, labeled as special purpose vehicles at fuel economy.gov, to the three truck types: truck SUV, 

van/minivan, or truck 

Sport utility vehicle (SUV) means a light truck with an extended roof line to increase cargo or 

137 
 

 

 

 

 

 

 

 

 

passenger capacity, cargo compartment open to the passenger compartment, and one or more 

rear seats readily removed or folded to facilitate cargo carrying. Generally, 2-wheel drive SUVs 

equal to or less than 6000 lbs GVWR are passenger cars for CAFE and GHG standards 

compliance, but continue to be labeled as SUVs. 

Station wagon means cars with an extended roof line to increase cargo or passenger capacity, 

cargo compartment open to the passenger compartment, a tailgate, and one or more rear seats 

readily removed or folded to facilitate cargo carrying. 

Track width –means the lateral distance between the centerlines of the base tires at ground, 

including the camber angle. 

Van means any light truck having an integral enclosure fully enclosing the driver compartment 

and load carrying compartment. The distance from the leading edge of the windshield to the 

foremost body section of vans is typically shorter than that of pickup trucks and SUVs. 

Wheelbase is the longitudinal distance between front and rear wheel centerlines. 

I. LINKS FOR MORE INFORMATION 

This report, Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 

1975 through 2014 (EPA-420-R-14-023) is available on the EPA’s Office of Transportation and 

Air Quality’s (OTAQ) web site at: epa.gov/otaq/fetrends.htm. The Executive Summary of 

this report (EPA-420-S-14-001) is available at the same web site. 

A copy of the Fuel Economy Guide giving city and highway fuel economy data for individual 

models is available at: fueleconomy.gov or by calling the U.S. Department of Energy at (800) 

423-1363. 

The website fueleconomy.gov provides fuel economy and environmental information for 

vehicles from model year 1984 through the present. The site has many tools that allow users 

to search for vehicles and find information on vehicle fuel economy, fuel consumption, 

estimated annual fuel cost, and CO2 emissions. The site also allows users to personalize fuel 

economy and fueling cost estimates based on personalized inputs for fuel cost, annual mileage, 

and percentage of city versus highway driving. 

EPA’s Green Vehicle Guide (epa.gov/greenvehicles) is designed to help car buyers identify the 

cleanest, most fuel-efficient vehicle that meets their needs. The site includes information on 

SmartWay certified vehicles, how advanced technology vehicles work, and infographics and 

videos that provide tips on saving money and reducing emissions through smarter vehicle 

choices. 

138 
 

 

 

 

 

 

 

 

 

 

 

For detailed information about EPA’s GHG emissions standards for motor vehicles, see: 

epa.gov/otaq/climate/regulations.htm. 

For information about automaker compliance with EPA’s Greenhouse Gas Emissions 

standards, including a detailed Manufacturer Performance Report for the 2012 Model Year, 

see: epa.gov/otaq/regs/ ld-hwy/greenhouse/ld-ghg.htm. 

For detailed information about DOT’s Corporate Average Fuel Economy (CAFE) program, 

including a program overview, related rulemaking activities, and summaries of the formal 

CAFE performance of individual manufacturers since 1978, see: www.nhtsa.gov/fueleconomy. 

For more information about the EPA/Department of Transportation (DOT) Fuel Economy 

and Environment Labels, see: epa.gov/otaq/carlabel/. 

J. AUTHORS AND ACKNOWLEDGEMENTS 

The authors of this year's Trends report are Jeff Alson, Aaron Hula, and Amy Bunker, all of 

whom work for the EPA Office of Transportation and Air Quality's (OTAQ) Transportation 

and Climate Division, at the National Vehicle and Fuel Emissions Laboratory in Ann Arbor, 

Michigan. Colleagues from OTAQ's Compliance Division, including Sara Zaremski, Linc 

Wehrly, Robert Peavyhouse, Karen Danzeisen, and Rob French provided critical access and 

expertise pertaining to the formal VERIFY data that comprise the Trends database. OTAQ 

colleagues Robin Moran, Kevin Bolon, and Susan Burke also provided helpful comments. 

The authors also want to thank Gwen Dietrich and David Levin of OTAQ for greatly 

improving the design and layout of the report. SRA International, under contract to OTAQ 

(contract number EP-C-11-007), provided key support for database maintenance, and table 

and figure generation. DOT/NHTSA staff reviewed the report and provided comments. Of 

course, the EPA authors take full responsibility for the content and any errors. 

The authors also want to acknowledge those OTAQ staff who 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. The late 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. 

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