WASHINGTON — WASHINGTON -- In a sign of congressional concern over near record-high gasoline prices and global warming, a Senate committee approved yesterday legislation calling for the most significant increase in vehicle fuel efficiency in decades.
The measure would boost the fleet-wide average fuel economy standards by 40 percent, from the current 25 miles per gallon to 35 mpg, by 2020. It now goes to the Senate, where a similar measure was defeated two years ago after heavy lobbying by automakers.
This time, the bill is backed by a number of lawmakers who previously opposed tougher standards. And congressional Democratic leaders have pledged to pass legislation to address climate change.
Cars and light trucks - including SUVs, pickups and vans - account for about one-fifth of U.S. carbon dioxide emissions.
"This marks a pretty significant change in the Congress," said Sen. Byron L. Dorgan, a North Dakota Democrat who has voted against tougher fuel-economy rules but is now sponsoring legislation to raise the standards.
The bill's approval by the Senate Commerce Committee marked the opening round. Lawmakers from vehicle-manufacturing states are vowing to fight the measure, which they say could hurt the struggling U.S. auto industry. Environmental groups also assailed the bill, saying it contains loopholes that could lead to efficiency increases smaller than those the bill promises.
The bill, the first major revision of the fuel-economy program established during the oil price shocks of the 1970s, would require each automaker's fleet of cars and light trucks sold in the country to average 35 mpg by 2020. A 4 percent annual increase in fuel economy would be required for vehicles made from 2021 to 2030.
The legislation would give the Transportation Department latitude to permit a lower standard if it determined that the costs of imposing stricter rules outweighed the benefits.
Currently, each automaker's car fleet must average 27.5 mpg, a requirement that has not changed for 18 years, and light trucks must average 22.2 mpg. That would increase to 24 mpg by 2011.
Meanwhile, gasoline prices moved back to center stage on Capitol Hill, with Democrats and Republicans sparring over each other's record in seeking to bring down energy costs.
Rep. Bart Stupak, a Michigan Democrat and chairman of the House Energy and Commerce subcommittee on oversight and investigations, announced that his panel will examine the causes behind fluctuations in fuel prices.
Desperate to do something to respond to high gasoline prices, the Commerce Committee attached to the fuel-economy bill a measure that would establish new federal penalties for gasoline price gouging.
Environmentalists expressed reservations.
"On the one hand, it's a start," said Dan Becker, director of the Sierra Club's global warming program. "On the other hand, it's a pretty weak start. It doesn't actually require the administration to act, so there is no guarantee that fuel economy goes up."
Joan Claybrook, a former administrator of the National Highway Traffic Safety Administration and current president of the watchdog group Public Citizen, called the bill "a political compromise that now compromises the very purpose of the fuel economy program."
The environmentalists pledged to work to strengthen the measure as it moves through Congress, though that could set up a veto showdown with President Bush, who has called for tougher fuel economy rules but opposes a standard that is required by Congress.
Auto industry officials called the tougher standards "unattainable" and contended that they would deny consumers the SUVs they cherish.
The United Auto Workers union also opposed the measure.
Richard Simon writes for the Los Angeles Times.