What is CAFE?

As part of the Energy Policy and Conservation Act of 1975, Corporate Average Fuel Economy (CAFE) requires automakers to comply with gas mileage or fuel economy standards set by the Department of Energy. The current CAFE standard for cars is 27.5 miles per gallon (mpg), and has not changed since 1986. The current CAFE standard for light trucks -- including SUVs -- is 20.7 mpg. This standard has been in place since 1996.

But don't some SUVs get significantly less than 20.7 miles per gallon?

Yes. CAFE is an average standard applied on a fleet-wide basis for each manufacturer. So, for example, the fuel economy ratings for a manufacturer's entire line of light trucks must average at least 20.7 mpg for the manufacturer to comply with the standard.

According to the Environmental Protection Agency (EPA), the most fuel efficient SUV is the Toyota RAV4, which gets 25 mpg in the city and 31 mpg on the highway. There is a three-way tie for least efficient SUV: the Land Rover Range Rover, Cadillac Escalade, and GMC K1500 Yukon Denali all get 12 mpg in the city and 15 mpg on the highway.

Which SUVs are the least and most polluting in their class?

According to the EPA's Green Vehicle Guide, for the 2002 model year, the cleanest SUVs are: the Chevrolet Tracker, Ford Escape, Kia Sportage, Subaru Forester, Suzuki Vitara, Suzuki Grand Vitara, and Toyota RAV4.

The SUVs named most polluting by the EPA are: the Cadillac Escalade, Chevrolet C1500 Avalanche, Chevrolet C1500 Suburban, Chevrolet C1500 Tahoe, Chevrolet K1500 Avalanche, Chevrolet K1500 Suburban, Chevrolet K1500 Tahoe, GMC C1500 Yukon, GMC K1500 Yukon, GMC K1500 Yukon Denali, Toyota Land Cruiser, and Toyota Sequoia.

Are any of the auto companies doing anything to address SUVs' environmental impact?

In what was seen as a startling admission, Ford published a report that was distributed to shareholders in which the company acknowledged that SUVs are environmentally unfriendly and can be a danger to drivers in smaller vehicles. Ford said that it made these admissions in an attempt to be more transparent, and that it was taking some steps to help address the problems. However, Ford said that it would continue to make SUVs in order to meet the strong market demand.