Events continue to drive home the fact that we have a once in a generation opportunity to fundamentally change automotive fuel economy regulations. Observers as diverse as Newt Gingrich and John Kerry agree that the problem of global warming is real, it is urgent, and significant actions need to be taken now. There is even general agreement that we need to reduce greenhouse gas emissions from all sources. Now comes the hard part: how to best achieve the needed reductions.

The automakers say they want to do their fair share to reduce global warming emissions, but they are fighting vehicle performance standards in D.C., in Vermont, in California — in any state that has the effrontery to have already capped vehicle global warming emissions. In light of the recent Supreme Court ruling, the automakers are supporting an economy-wide cap, probably because they believe the greatest burden will be borne by other industries.

The domestic automakers say there is little more they can do to improve fuel economy without a technological breakthrough and billions of dollars. But they invest billions of dollars every year in engine research heretofore to make vehicles heavier and faster – something my research shows that American consumers stopped demanding when the price of gas starting going up. GM’s Vice Chairman Bob Lutz even complained that to improve fuel economy would consume the “quasi-totality of our investment in engineering resources.” and “You can either spend the money meeting the law or spend the money to do the cars you’d like to do but you can’t do both.” The cars Americans would like Detroit automakers to make—the cars America needs Detroit automakers to make–apparently differ fundamentally from those that GM likes to make. Could this explain their sliding market share? Will it take the loss of the quasi-totality of their market share—and the American jobs they support—to change this attitude?