Environment: Deadline for Detroit

Never before have U.S. automakers been so much on the defensive—or in such deep trouble. Testifying before officials of the Environmental Protection Agency in Washington last week, executives of General Motors, Ford, Chrysler and American Motors stated that their vehicles could not meet the strict—and, Detroit says, unrealistic —standards for exhaust emissions set by Congress in the Clean Air Act of 1970. Each of the companies asked for more time—at least one year—to produce cleaner cars.

The Clean Air Act now leaves it up to William D. Ruckelshaus, administrator of the Environmental Protection...