No blood for oil! was the rallying cry for the anti-war environmental left opposed to Operation Desert Storm. Yet these same activists are now urging just this kind of trade-off by supporting a bill by Sen. Richard Bryan, D‑Nev., which proposes new, stringent auto fuel-efficiency standards.

Although they didn’t believe that the liberation of Kuwait and the overthrow of Saddam Hussein was worth a single American life, they apparently believe that requiring automakers to sell cars that get an average of 40 miles a gallon is worth between 75,000 and 149,000 American lives over 10 years — between 1,800 and 3,600 in Missouri alone.

This staggering body count is based on a recent Harvard University-Brookings Institute study that concluded that the existing corporate average fuel efficiency (CAFE) standard, which requires automakers to ensure that their auto fleet gets an average of 27.5 mpg, has been directly responsible for between 34,900 and 67,300 highway fatalities over 10 years.

If the CAFE standard were increased to 40 mpg, as proposed by Bryan and his environmentalist allies, this death toll would more than double, according to Robert Crandall of the Brookings Institute, co-author of the study.

Indeed, the relationship between high-mileage cars and body-bags is the strongest finding of the past two decades of auto-safety research. Why? Because cars generally get good mileage by decreasing body weight and “downsizing.” The average weight of a car fell to 3,100 pounds in 1989 from 4,100 pounds in 1975, when CAFE was first passed by Congress. Although fuel efficiency more than doubled (without, incidentally, decreasing our oil imports) so did the vulnerability of American motorists.

Even Ralph Nader, one of the most prominent advocates of a 40 mpg CAFE standard, concedes that “larger cars are safer — there is more bulk to protect the occupant.”

Larger cars, however, could never meet a 40 mpg standard. There is no “magic carpet” technology to do so, no matter how much we wish there were.

The Department of Energy estimates that, at best, a 40 mpg CAFE standard would save 500,000 barrels of oil a day. By means of comparison, simply reducing gasoline volatility standards (adopted to reduce hydrocarbon emissions from cars) would save 27.4 million barrels of oil annually. Environmentalists, of course , would object to such a strategy, being more willing to sacrifice tens of thousands of lives than accept even a marginal reduction of air quality.

Although proponents claim that the CAFE standard was responsible for increased automobile fuel efficiency since 1975, Crandall believes that increased fuel prices, and thus increased market demand for fuel-efficient cars, made certain that America would have made these same gains in automobile efficiency without CAFE.

Moreover, numerous studies have found that cars that get better mileage tend to get driven more often than cars that don’t. It simply makes driving relatively cheap for motorists. The increase in miles driven by automobiles is expected to largely offset any gains in fuel efficiency standards as far as gasoline consumption is concerned.

A higher CAFE standard could also encourage people to hold on to their older, larger cars a few years longer than they might otherwise, or turn to the used-car market for models no longer available. Why? Because people don’t like driving in breadboxes. Only 2.7 percent of all new car purchases are from among those that meet the Bryan standards. But in a 40 mpg CAFE world, the Ford Escort, according to automobile market consultants, would become the standard for a “family-sized car.”

Consumer reluctance to buy these highway equivalents to the golf cart will not only mitigate potential fuel-efficiency gains but increase air pollution. Older cars generally emit more pollutants than newer cars. In fact, 83 percent of all automobile pollutants come from pre-1981 cars. Any policy that encourages used-car purchases or the retention of older cars, according to the Brookings Institute, will lead to increased air pollution.

If not CAFE, then, what do we do to encourage energy conservation? We rely on an old concept now universally popular in every corner of the world save that of our own nation’s capital — the free market. Since energy costs are considered an expensive overhead for business, there is every incentive in a free market to increase energy efficiency and thus increase profits. This has indeed happened. Since 1970, the amount of energy that America has used to produce each dollar’s worth of products has fallen by nearly a third, while GNP has nearly doubled. Undeterred by the facts, however, the environmentalist drumbeat goes on for “mandatory conservation.”

There is some reason to believe, however, that these facts aren’t falling on deaf ears. Sen. Bryan, for example, continues to drive a comfortable, safe Oldsmobile 98.