AUTOS: Return of the Lead Sleds

Like dry martinis and folk music, another icon of the 1960s is coming back: the big, long car. Among several 1989 models that General Motors unveiled last week was the new Buick Riviera, fully 11 in. longer than the 1988 version. The Cadillac division's new Fleetwood and DeVille models are as much as 9 in. longer than last year's cars, and they even sport a discreet version of their old tail fins.

Customers are buying such boaty vehicles because gasoline is relatively cheap, and GM and Ford are determined to satisfy the demand. Even though the cars are more fuel efficient than comparably sized models of the 1960s and early '70s, their tendency to guzzle gas is causing headaches for the two largest U.S. automakers. Last week GM and Ford executives urged federal regulators to modify a fuel-economy law, passed in the energy-crisis year of 1975, that would require 1989 fleets to get an average of 27.5 m.p.g., up from 26 m.p.g. this year. GM is asking for a smaller increase, to 26.5 m.p.g.

If the higher standard is imposed, GM claims, the company will lose market share to foreign competitors and could be forced to lay off as many as 60,000 workers. Environmentalists blasted the automakers' proposal to modify the fuel-economy law, contending that it would increase hydrocarbon pollution and aggravate the greenhouse effect.