A mile and a half makes a difference

IT'S tempting to wonder what all the fuss is about now that the administration has decided to reduce from 27.5 to 26 the average mileage that automakers' new cars must get per gallon. After all, it's only a mile and a half, and we're in a time of oil glut. But there are two good reasons why the mileage drop is unfortunate: One concerns energy, the other government shifting.

Cumulatively the 11/2-mile-per-gallon difference would have a considerable effect on US energy use. Americans own some 10 million cars now and drive them perhaps 100,000 miles. If those cars averaged 26 miles to a gallon of gas instead of 27.5 miles, over their lifetime they would burn an extra 2.1 billion gallons of gas, according to the computations of the Center for Auto Safety, which opposes the change.

The world now is awash in extra crude oil, but that is a nonrenewable source of energy. Ultimately other kinds of energy will have to be found. It is in everyone's interest not to use unnecessary amounts of gasoline now, to ensure that the worldwide supply of crude oil last as long as possible.

Chrysler Corporation deserves credit for having met the higher average standards. General Motors and Ford both claimed they could not, and the government acceded by lowering the number. The two might well have been able to comply if they had replaced with new models their large, older-style rear-wheel drive cars, which make a large profit but use much fuel.

The decision to roll back the mileage standard sends manufacturers the wrong message: If they find it difficult to meet government standards, government may come to the rescue by easing the standards.

For years a significant problem for government credibility both domestically and internationally has been just such shifting of US policies. Defense contractors say one reason for the high costs of some weapons is that the government speeds up and slows down procurement rates. Allies complain about shifting policies, too.

No one would suggest that government policies should be set in stone. Yet for government to retain full credibility, it is important that there be constancy. Changes should be kept to a minimum. The gasoline mileage standard is one change that should not have been made.