All new automobiles sold in the United States by the fall of 1983 must be equipped with air bag safety devices or passive seat belts that lock into place in the event of crashes. Secretary of Transportation Brock Adams announced yesterday.

Under an order Adams detailed at a news conference, two front seat position safety devices must be installed on all standard and luxury size cars for model year 1982, on sale in the fall of 1981.

The requirement will be extended to intermediate and compact cars for the 1983 models and to subcompact and minisize automobiles for model year 1984. Adams estimated the cost at between $100 and $300 a car for installation of air bags and less than $100 for new seat belts.

Under legislation that authorized the Department of Transportation to establish automobile safety standards, yesterday's decision may be over-turned only if both houses of Congress vote in favor of a veto within 60 working days.

Adams said he believes Congress will support the decision and he promised to fight for it.

However, a ranking Republican on transportation issues, Rep. E. G. (Bud) Shuster (R-Pa.), introduced legislation to overturn the DOT order within hours of the Adams news conference. "There is no hard evidence that air bags will save lives and it could cost American consumers over $20 billion." Shuster said.

Chrysler Corp. also denounced the government decision, stating it will force "the American people to pay triple the cost for a second-best safety system." Chrysler, the nation's third largest car manufacturer, said mandatory use of current seat belts would save 50 per cent more lives than air bags and it called on Congress to support a veto.

American Motors Corp., the smallest U.S. manufacturer, condemned the Adams decision as a "multibillion-dollar gamble with consumers' money."

General Motors Corp. and Ford Motor Co., the two largest auto makers, were much more restrained.

"Should Congress uphold the decision, General Motors intends to do the best possible job to equip our cars with passive restraints in accordance with the regulations." said GM's vice president for environmental affairs, David S. Potter.

A Ford official in Detroit expressed satisfaction that Adams had recognized "lead-time problems" in auto manufacturing but declined additional comment.

Consumer advocate Ralph Nader, who shared a luncheon table with Adams at the Washington Press Club news conference yesterday, obviously was pleased that the government had acted in favor of a safety device he long has supported.

But Nader condemned the Adams decision to delay implementation for several more years. The statute does not call for "phasing in" various size cars in different years, he said, noting that Detroit has been able in recent years to develop new cars from the drawing board to sales rooms in less than two years.

Air bags, which have been in the research and development stage for more than a decade, are balloon-like devices that inflate instantaneously when a crash occurs: they are supposed to prevent passengers from being thrown into the windshield or steering column.

Passive seat belts, already introduced in some automobiles by Volkswagen, are like harnesses that wrap around passengers when the car door is closed. The belts lock a rider in place when a crash takes place.

According to Adams, use of either of these devices on all 10 million cars produced annually for sale in the United States could save 9,000 lives each year. "I cannot in good conscience be a party to further unnecessary delay. . . The issue of automobile safety has dragged on too long," Adams said.

At the same time, he defended his decision to delay implementation of mandatory air bags for several more years. He told reporters that auto manufacturers must be given adequate time to gear up production lines not only for new safety devices but also to meet new federal emission and fuel-economy measures, announced earlier this year.

Earlier this year, several auto manufacturers agreed to a plan by former DOT Secretary William T. Coleman Jr. for production of up to 500,000 cars with air bags or passive seat belts on an experimental basis. He called on these companies to continue with that agreement and GM said it would give the secretary's request "every consideration."

Eaton Corp., of Cleveland, a developer of air bags, hailed yesterday's decision as "the optimum way to provide additional safety," permitting sufficient time to complete testing.