Credits allow auto makers to show fleet fuel economy has slipped just slightly

At its current 24.5 level, the fleet of American cars and trucks appears to be just slightly worse than 2000's 24.7 miles per gallon and well below the high average in 1987 of 26.2 miles per gallon.

Misleading

But the 24.5 figure is misleading, according to analysis done by The New York Times newspaper. After certain fuel-economy credits are taken into account, the average fuel economy falls to 20.7 miles per gallon, a level not seen since 1979.

Those credits include cars and trucks that can run on various fuel types, so-called dual-fuel vehicles, including natural gas and petrol fortified with ethanol, a controversial fuel derived from grains.

The credits associated with dual-fuel vehicles have allowed manufacturers, such as Ford, DaimlerChrysler and General Motors, to avoid fines levied on car makers who fail to achieve Corporate Average Fuel Economy (CAFE) standards.

Regardless of which figure is used - 24.5 or 20.7 - the fact remains that the average fuel economy of cars and trucks in the US is falling from its high of 26.2 miles per gallon in 1987.

That was before a booming economy and cheap petrol prices led Americans to fancy huge SUVs with their huge eight-cylinder engines not just as a source of transportation but as a status symbol as well.

Roots in energy crisis

Fuel economy standards have their roots in the energy crisis that struck the US in 1973 and caught US car makers unaware.

They were established by the US government following the 1970s energy crisis and called for raising fuel economy standards for cars and trucks progressively each year.

Those standards, the CAFE standards, were raised incrementally throughout the 1980s until they reached 27.5 miles per gallon for automobiles in 1990, according to the NHTSA.

However, light trucks, a grouping into which today's SUVs fall, must only achieve 20.7 miles per gallon due to recent congressional inaction, which has failed to address a standard for a broad range of vehicles from pickups to vans to SUVs.

According to the report, light trucks from GM and DaimlerChrysler failed to meet that standard. The average fuel economy of GM's 2001 light trucks is 20.6 miles per gallon, and DaimlerChrysler's average is 20.5 miles per gallon. Ford met the standard.

Curiously, the NHTSA report shows that domestic car makers edged out imports by a slight margin - 28.8 miles per gallon against 28.5 miles per gallon - in fuel efficiency across a range of vehicles.