Democrat Edward Markey of Massachusetts, who sponsored the proposal, said higher fuel standards were needed to reduce oil demand and make the United States less dependent on foreign petroleum suppliers like OPEC.

"The price of oil is controlled by OPEC," said Markey. "We can't break (the cartel) up."

US oil demand averages averages 21 million barrels a day, with imports supplying three of every five barrels consumed.

With gasoline demand the biggest component of oil consumption at about 40 percent, many environmentalists say the only way to significantly reduce petroleum demand is to boost vehicle fuel efficiency.

But committee Democrats from Michigan, where the auto industry is based, said Congress can't mandate what type of automobiles Detroit should make.

"People are driving around in big cars, because they like them, because they feel safe," said Democrat John Dingell of Michigan.

Opponents to the amendment said higher mileage requirements would force automakers to produce dangerous, small cars to meet the stronger fuel standard.

"You'll never get your soccer moms and soccer kids in there," said Democrat Bart Stupak of Michigan, referring to the feared subcompact vehicles. "It's not what Americans want."

The House Energy and Commerce Committee is set to finish working on the energy bill this week, and send it the House floor for a final vote.

Democrats plan to offer several more amendments before then to try to modify the legislation.

One of their more contentious proposals will try to strike a provision in the bill that protects major oil companies from lawsuits over the water-polluting gasoline additive MTBE.

House Majority Leader Tom DeLay of Texas wants the MTBE liability waiver be part of energy legislation, even though the Senate rejected an energy bill last year largely because of the MTBE protection.

Two other House committees on Wednesday considered other parts of the energy bill that will be folded into much broader legislation that may be voted on by the full House next week.

Despite Democratic objections, the House Resources Committee was set to vote to allow oil companies to drill in Alaska's Arctic National Wildlife Refuge.

Giving oil companies access to the refuge's 1.5-million acre coastal plain and billions of barrels of crude oil is a key part of the Bush administration's national energy plan.

Separately, the House Ways and Means Committee approved about $8 billion in tax breaks and financial incentives to boost US energy infrastructure and encourage the use of certain energy technologies.