Sens. John Kerry and John McCain announced a compromise proposal Thursday to increase automobile fuel economy to 36 miles per gallon by 2015 and are considering an exemption for pickup trucks to satisfy senators from agricultural states.

The measure would allow automakers to satisfy up to 10 percent of the requirement by trading emission credits with other companies that produce greenhouse gases, from power plants to factories to dry cleaners.

Current standards, known as CAFE for Corporate Average Fuel Economy, are 27.5 mpg for cars and 20.7 mpg for light trucks. Automakers doneet the requirement for every vehicle, but their entire fleet must average the standard.

The CAFE provision is among the most contentious issues in a sweeping energy bill being debated this week in the Senate. It is strongly opposed by the auto industry, the United Auto Workers Union and most Republicans.

Opponents claim the proposal would require automakers to build smaller cars that get better gas mileage but are less safe and that American consumers don't want. Said one minivan owner who appeared with at a press conference with opponents of the bill, "If CAFE standards were increased, I can't even imagine how I would get my kids from point A to point B."

Kerry, D-Mass., said the auto industry is pushing false arguments in an attempt to defeat the bill. He said it would reduce dependence on foreign oil and cut greenhouse gas emissions.

"No one in America will have to drive a smaller car," he said. "They are doing a scare tactic on soccer moms."

However, Kerry said he is negotiating with other senators on adding a fuel economy exemption for pickup trucks. Senators from agricultural states are being pressured by farmers who use pickups as work vehicles to oppose an increase in CAFE standards.

Sen. Zell Miller, D-Ga., has introduced an amendment to keep pickup fuel economy requirements at 20.7 mpg. He even wrote a song about it called the "Talking Pickup Truck Blues," that includes the line:

"Sure, an SUV is classy travel, but it ain't much good for hauling gravel or hay seed or bovine feces. So please do not make my pickup truck an endangered species."

"Now, I will be the first to admit that song has not climbed to the top of the charts," Miller said on the Senate floor. "But here is the point we are making — do not mess with the working machine of the American road. Do not mess with pickups. Farmers depend on them."

Sens. Carl Levin, D-Mich., and Kit Bond, R-Mo., plan to introduce an alternative to the Kerry-McCain amendment that calls on the National Highway Traffic Safety Administration to set higher fuel economy standards.

The Levin-Bond amendment orders NHTSA to raise CAFE for cars and light trucks, but does not require a minimum increase.

Kerry and McCain, R-Ariz., each introduced similar CAFE proposals last month. McCain's would have required a 36 mpg standard by 2016, while Kerry's required a 35 mpg average by 2013.

At least four other Republicans — Sens. Olympia Snowe and Susan Collins of Maine, Lincoln Chafee of Rhode Island and Gordon Smith of Oregon — are publicly supporting the Kerry-McCain proposal. Both sides say they expect the vote to be close in the narrowly divided Senate.

The auto industry has aggressively lobbied against both the Kerry and McCain proposals and says their compromise is no better.

"You could call it the splitting hairs compromise because it doesn't address any of the issues on jobs, vehicle safety and consumer choice," said Gloria Bergquist, spokeswoman for the Alliance of Automobile Manufactuers. "It may make the chief sponsors feel better, but nobody else feels better about it."