To get a sense of the auto industry's progress in fuel efficiency, look no further than the 2002 Chevy Blazer. The model with automatic transmission, six cylinders, and four-wheel drive gets 18 miles per gallon (mpg), two miles less than a comparably equipped Blazer did in 1985. Indeed, in those 17 years the average fuel economy of the entire fleet of U.S. cars and light trucks declined from 26 mpg to 24 mpg-in part because of the rising proportion of gas-guzzling sport-utility vehicles (SUVs). Yet in March, when auto industry lobbyists claimed that building more fuel-efficient cars would be "too difficult," the U.S. Senate once again killed legislation that would raise the country's Corporate Average Fuel Economy standards. It was a familiar dance; Congress has not raised the standards even once during those same 17 years.

It's not that automotive technologies haven't improved; it's that the improvements have been geared toward delivering power, not efficiency. Since 1981 the auto industry has hiked horsepower 84 percent, allowing vehicles to accelerate faster even though they have gotten heavier, according to the U.S. Environmental Protection Agency. "That's what consumers want," says Fritz Indra, executive director of advanced engineering for General Motors' Powertrain division. "Each year Americans want a little more space inside, a little more power."