The CAFE fight will advance to the floor of the U.S. House sometime within the next two weeks, and no one appears to be less rigid or shrill on either side of it. That's too bad, because there are potential compromises, as part of the energy bill under consideration, that could set the stage nicely for action later this year on global warming.

Automakers, like appliance makers, should have reasonable goals for increased efficiency and perhaps even the equivalent of an Energy Star award for their thriftiest models. Left to their own devices, they have shown a clear preference for converting every technological advance into faster acceleration, more towing power or bigger vehicles, rather than better mileage. Even Toyota has tumbled to U.S. consumer preferences by moving into the full-size truck line with its Tundra.

But there is a big difference between nudging an industry toward reasonable efficiency gains and telling it what the overall sales mix has to be in terms of miles per gallon nationwide. No one tells refrigerator manufacturers they have to sell enough small refrigerators to balance out the big ones. A fleet average rule may only succeed in convincing drivers to keep their older, bigger vehicles longer — meanwhile causing havoc for the domestic industry if it can't adjust its vehicle mix fast enough.

Detroit faces an overload of fear factors. Not the least of them is that careless regulation, such as the 35-mpg fleet requirement passed by the U.S. Senate and part of a companion amendment being prepared for the House debate, could put the domestic manufacturers out of business. Furthermore, it's not clear how regulations will account for other innovations that save gas, such as biofuels and plug-in hybrid engines, that could have a huge impact on gas consumption but will depend on the day-to-day choices made by consumers as they fuel their vehicles.

That's why it's far better to make fuel prices the focal point for action, whether the point is to cut back on the use of foreign oil or to address global warming. Facing a mix of subsidies to boost alternative fuels and a carbon tax to discourage the use of fossil-fuel products, Detroit's automakers would still face difficult decisions and not all may survive. But the force for change will come from drivers' knowing that the cheap-oil era has ended, not from a government mandate that uses automakers as a blunt instrument to try to shape a marketplace ruled by individual choices about when to replace a vehicle and with what.

The energy bill should have room for gradual efficiency improvements by vehicle class, making sure manufacturers don't backslide if oil prices drop. But if Congress wants drastic change, it will have to look seriously — and bravely — at U.S. Rep. John Dingell's proposal for a carbon tax as the best available tool.

— Detroit Free Press