GM may pull the plug on plans to introduce a host of new RWD cars due to a proposal from the Bush administration that would raise corporate average fuel economy (CAFE) standards by 4% a year, with fleets expected to average 34mpg by 2017 – 30% higher than today’s levels.

In an interview with the Chicago Tribune, GM’s Vice Chairman Bob Lutz said "we've pushed the pause button. It's no longer full speed ahead." Although the Camaro is safe, it’s development is near completion, plans for cars such as the next-generation Pontiac GTO, Chevrolet Impala replacement and possible new sedans from Buick and Cadillac may have to be shelved. "It's too late to stop Camaro, but anything after that is questionable or on the bubble," Lutz revealed.

The basis for the new range is GM’s new Zeta large car platform but the cars would be heavier and offer more performance than their FWD counterparts and thus be difficult to achieve fuel economy levels the new CAFE proposal demands. As Lutz puts it, “we don't know how to get 30% better mileage from RWD cars.”

"We'll decide on our rear-drive cars when the government decides on CO2 levels and CAFE regulations," he said, adding that meeting the new standards would increase vehicle costs by at least $5,000, an amount most new car buyers won’t be willing to part with.