WASHINGTON -- The Bush administration's proposed fuel economy standards for 2011-15 are far too high given the "economic stress" the auto industry faces, a key industry lobby said today.

The Alliance of Automobile Manufacturers asked the National Highway Traffic Safety Administration to reconsider its plan to raise standards by 4.5 percent a year during the 2011-15 model years.

By 2015, under the plan, cars would have to average about 35.7 mpg and trucks would have to average about 28.6 mpg -- about 25 percent higher overall than today.

The proposal "would require manufacturers to expend resources at a pace that is excessive given the fact that the auto industry is already under economic stress," the alliance said in formal comments reacting to preliminary rules NHTSA unveiled in April.

Today, July 1, is the deadline for comments on the plan. The Bush administration has promised to issue final fuel efficiency rules by year end.

The rules for 2011-15 are the first major step toward enforcing a new law that requires vehicles to average at least 35 mpg by 2020 -- about 40 percent higher than today. It is the first congressionally mandated increase in more than 30 years.

The alliance represents the Detroit 3, Toyota and six other automakers, which together have about 80 percent of the U.S. new-vehicle market.

In its comments, the alliance also complained that the NHTSA proposal underestimates costs of compliance and overestimates the social benefits of higher standards.

The Consumer Federation of America drew the opposite conclusion. In a telephone news conference today, Mark Cooper, the federation's research director, said the NHTSA plan underestimates benefits of higher standards. It also fails to take into account all of the fuel-saving technologies automakers could add to vehicles, Cooper said.

NHTSA got "just about everything," wrong, Cooper said. He said NHTSA should raise its proposed standards for 2011-12 and withdraw the standards for 2013-15, so that the next administration is not locked into the Bush rules for that period.

BMW of North America called on the Bush administration to create an alternative fuel economy program for automakers that would be hit hardest by the proposed 2011-15 standards.

The alternative would allow a company such as BMW to comply by raising the average fuel efficiency of its vehicles by 4.5 percent a year over the standards in effect in 2010, the automaker said in its comments.

The administration has proposed sliding scales of fuel efficiency targets for cars and trucks of different sizes. Each vehicle would be measured by its footprint -- roughly the area bounded by four wheels. Each automaker would have its own standards to meet, based on the mix of vehicles of different sizes that it sells.

BMW's cars would need to average 37.7 mpg in 2015, compared with the industry average of 35.7 mpg. Its trucks would need to average 31.7 mpg, compared with an industry average of 28.6 mpg, according to the preliminary rules.

The car standard today is 27.5 mpg. The truck standard is scheduled to rise gradually to 23.5 mpg by 2010.

In its official comments, BMW said the administration proposal "is not feasible" for its vehicles. Otherwise, BMW, an alliance member, said it supports the alliance's comments.