Light Duty Vehicle Fuel Economy Makes No Improvement Over 2005

Model year [MY] 2006 vehicles offer an average estimated fuel economy rating of 21.0 mpg. This average is the same as last year and in the middle of the 20.6 to 21.4 mpg range that has occurred for the past fifteen years, and five percent below the 1987 to 1988 peak of 22.1 mpg, according to the EPA’s just-released report, Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2006.

Green Car Congress [GCC] reports that MY2006 light-duty vehicles are estimated, on average, to be the heaviest, fastest and most powerful vehicles than in any year since EPA began compiling such data.

Since 1975, the fuel economy of the combined car and light truck fleet has moved through four distinct phases:

A rapid increase from 1975 to the mid-1980s;

A slow increase extending into the late 1980s;

A decline from the peak in the late 1980s until the mid-1990s; and

A period of relatively constant overall fleet fuel economy.

After two decades of constant growth, light truck market share has been relatively stable for five years, and represents about 50% of the total market, GCC reports. Growth in the light truck market was primarily due to the increase in the market share of SUVs, which increased their share by more than a factor of ten, from less than two percent of the overall new light-duty vehicle market in 1975 to more than 25% of vehicles built each year since 2002.

For obvious reasons, the increased market share of light trucks, which in recent years have averaged more than 6 mpg less than cars, accounted for much of the decline in fuel economy of the overall new light-duty vehicle fleet from the peak that occurred in 1987-88.

Improved engine, transmission, and powertrain technologies continue to penetrate the new light-duty vehicle fleet every year. However, the trend has clearly been to apply these innovative technologies to accommodate increases in average new vehicle weight, power, and performance while maintaining a relatively constant level of fuel economy [see graphic below].

At the peak of industry-wide fuel economy in 1987, some automaker groups had average fuel economies 6 to 8 mpg higher than others.

In MY 2006, the gap has decreased to a maximum difference between automakers of an estimated 5 mpg, with a typical difference between higher and lower fuel economy marketing groups being 3 to 4 mpg, GCC reports.

For MY2006, Honda, Toyota, Hyundai, and Volkswagen all have estimated fuel economies of 23.5 to 24.2 mpg, while General Motors, Nissan, Ford, and DaimlerChrysler all have estimated fuel economies of 19.1 to 20.5 mpg. Each of these groups has lower average fuel economy today than in 1987 [see graphic below].

The fuel economy values in the report are based on “real world” estimates provided by the Federal government to consumers and are about 15% lower than the values used by manufacturers and the Department of Transportation (DOT) for compliance with the Corporate Average Fuel Economy (CAFE) program.

Because it has been more than two decades since the current procedures for determining real world fuel economy estimates were established and because both vehicle technology and vehicle driving patterns have changed, EPA has proposed changes to the methodology for calculating real world fuel economy estimates and expects to finalize a new methodology by the end of 2006.

Resources:

Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2006"

[A hat tip to Green Car Congress]