The New CAFE Standards

Jan. 15, 2008 — -- The 40 percent increase in the U.S. fuel-economy standard to 35 miles per gallon by 2020, which Congress passed last month, could be a significant step toward trimming U.S. drivers' increasing greenhouse-gas emissions and dependence on imported oil. But energy experts say that the new technologies required to meet the new standards are minimal. Instead, they say that lesser-known provisions in the Energy Independence and Security Act could have a far greater impact on spurring the development of new technologies, such as plug-in electric vehicles.

The new law tightens Corporate Average Fuel Economy (CAFE) standards that regulate the average fuel economy in the vehicles produced by each major automaker. The current CAFE standard for cars, set in 1984, requires manufacturers to achieve an average of 27.5 miles per gallon, while a second CAFE standard requires an average of 22.2 miles per gallon for light trucks such as minivans, sport utility vehicles, and pickups. The new rules require that these standards be increased such that, by 2020, the new cars and light trucks sold each year deliver a combined fleet average of 35 miles per gallon.

Raising fuel economy by 10 miles per gallon nationwide will deliver real benefits. The Union of Concerned Scientists, for example, estimates that it will save 1.1 million barrels of oil per day in 2020--about half of what the United States imports from the Persian Gulf. That should deliver a reduction in greenhouse gases equivalent to taking 28 million of today's cars and trucks off the road. Nevertheless, Jim Kliesch, a senior engineer with the Union of Concerned Scientists, in Washington, DC, projects that these savings will be largely negated in 2020 by increased driving.

"Fuel-economy policy in this country had been stagnating for decades, and getting a minimum of 35 mpg by 2020 is a critical first step, but if we want to achieve a sustainable transportation system, it's going to take much more," says Kliesch.

Analysts like Kliesch do expect automakers to produce more advanced diesel vehicles and hybrids in the coming decade, both in response to tightening fuel-economy rules and for strategic and marketing reasons. But reports by the U.S. National Academy of Sciences, think tanks, and activists show that a combination of existing efficiency options, such as continuously variable transmissions and better tires, can cheaply and easily deliver a 35-miles-per-gallon fleet. (See "Why Not a 40-MPG SUV?")