THE EPA automobile mileage ratings for 1982

were released last week, showing dramatic improvement in the fuel economy of many American cars. For the first time an American car (equipped with a Japanese engine) broke into the top 10, still dominated, as it has been for five years, by Volkswagen. This Chevrolet Chevette diesel scored another first by achieving 40 miles per gallon. The Dodge Colt and the Plymouth Champ at 39 mpg also made it into the top 10; both, despite their names, are Japanese- made. Not one of the 10 top finishers has an American-made engine.

All of the American makers should easily exceed the 1985 federal mileage standard. Chrysler predicts that it will do so this year. Moreover, consumers will be happy to find that the single mileage figure EPA now reports--which is the same number that used to be reported for "city" driving--comes much closer to what the car owner can actually expect to get on the road. Any of the mileage ratings--highway, city or composite--can be used to compare different cars. But to avoid disappointment, car buyers should ignore the highway and composite mileage figures used in automobile advertising.

Also in the category of good news is the Department of Transportation's decision to continue crash testing of automobiles and publication of the results. The decision by National Highway Traffic Safety Administrator Raymond A Peck Jr. to abandon the previously used pass-fail rating system in favor of straight reporting of the crash scores is also a move in the right direction. Though there will be more numbers, consumers will have more--and more accurate--information.

American auto makers have objected strenuously to the government's safety testing program, arguing over various alleged deficiencies in the tests. The tests are not perfect, but the test now being used--a head-on crash into a solid barrier--is both the toughest and the one that produces the most consistent, reliable results. The dramatic improvement between 1980 and 1981 in the scores of the Honda Civic shows precisely why the tests are so important. Instead of contesting the Civic's bad results, as American makers are wont to do, Honda promptly made several design changes and one year later passed the '81 test easily.

With more than 50,000 lives still being lost each year in traffic accidents, and with the shift to lighter cars potentially raising the risk, the government's safety program is more important than ever. To make it useful to consumers, however, one more change is needed. Crash test results should be required on new car stickers, as the mileage ratings are.

Detroit frequently complains that American consumers force it to compete on the basis of 19 possible upholstery color combinations, rather than on the quality of its engineering. The EPA mileage testing program has shown that when other information is made available in a way that consumers can use--not simply published in a government press release--it becomes a major element in consumer choice. If mileage is that important, surely safety is even more so.