The U.S. Senate will devote most of March to debating a $35-billion energy package that supposedly will protect Americans from both greedy sheikhs and global warming. But if enacted as proposed, the measure actually would result in a good deal of American blood needlessly spilled on U.S. highways.

At the heart of the proposal is a dramatic tightening of automotive fuel economy standards fleet-wide to 35 miles per gallon by 2013. Current standards require passenger cars to average 27.5 mpg and light trucks 20 mpg.

But the vehicle downsizing necessary to meet such a standard would jeopardize the safety of American motorists far more than any threat posed by an oil embargo or melted ice caps. For all the fury against trading blood for oil in foreign policy, the fuel economy chorus largely disregards the lives lost to satisfy mileage requirements.

Seizing on the events of Sept. 11, proponents of stricter fuel efficiency standards have taken to claiming that our "dependence" on foreign oil increases the nation's vulnerability to terrorism. National security thus demands that we surrender our "gas-guzzling" sport utility vehicles for knee-scraping subcompacts.

Given that gasoline is priced less than bottled water these days, there's no evidence of a petroleum shortage. Nor has the regulatory regime known as CAFE (Corporate Average Fuel Economy) succeeded in reducing U.S. imports over the past two decades. In fact, foreign oil as a share of U.S. consumption has actually risen some 17 percent since CAFE kicked in.

Although Congress evidently prefers to demonize Detroit, it is misguided government policy that most often disrupts the energy market. As chronicled by Donald Losman of the National Defense University, the worst of the `70s oil shocks, for example, were more a consequence of federal price controls  than OPEC's market muscle.

Fortunately, Americans have heeded their own experiences rather than the tired rhetoric of the auto-bashers. Indeed, small trucks comprise nearly half the vehicles on the road today, and most motorists instinctively know what empirical research and the laws of physics confirm: larger vehicles are safer than small ones.

But stricter CAFE standards would require further downsizing of the nation's fleet. A 10-percent reduction in weight, for example, increases mileage by 8 percent on average, according to the National Highway Traffic Safety Administration.

However, reducing vehicle weight by 500 pounds also increases crash fatalities between 14 percent and 27 percent annually (2,000 to 4,000 additional deaths), according to research by Harvard University and the Brookings Institution. And the Insurance Institute for Highway Safety has found that cars with a curb weight under 2,500 pounds account for two-and-a-half times as many crash fatalities as sport utility vehicles weighing 5,000 pounds or more.

Not only are SUVs deemed wasteful, but CAFE advocates claim they pose a mortal threat to the sedan-driving public. According to the Insurance Institute for Highway Safety, passenger car occupants are 27 times more likely to be killed in a side-impact crash with an SUV than those riding in the larger vehicle. This fact supposedly also warrants the size limitations that tougher CAFE rules would impose.

But it is also a fact that highway fatality rates have fallen more than 20 percent during the same period in which SUVs have swelled in number. According to government statistics, the fatality rate per 100 million vehicle miles of travel fell to a historic low of 1.5 in 2000, the latest year for which statistics are available.

The improved fatality rate is undoubtedly driven, in part, by the rarity of fatal collisions between passenger cars and SUVs, which account for a mere 4 percent of all car-occupant deaths. Single-car crashes actually account for 42 percent of all highway fatalities.

Driving habits largely beyond the reach of government intervention are the primary cause of most traffic fatalities. Nearly two-thirds of those killed in crashes were unbuckled, and 40 percent of all traffic deaths were alcohol related.

As to the notion that SUVs are major contributors to global warming, Robert Crandall of the Brookings Institution has shown that emissions from all new vehicles amount to around 2 percent of all CO2 emissions in the U.S.  "Changing truck fuel standards is an inefficient way to address global warming," he says. 

Congress has been fully apprised of CAFE's inherent dangers. In the upcoming Senate debate, then, lawmakers need only decide whether to score political points or save American lives.