The latest dramatic reminder of this country's dependence on Persian Gulf oil has set off demands from conservation and environmental groups for strong measures to reduce oil consumption -- measures the Bush administration is unwilling to support.

Organizations such as the Sierra Club and the Alliance to Save Energy want policy makers to focus less on protecting supplies of oil and more on reducing the need for it.

In particular, the groups are seeking passage of a bill that would require automobile manufacturers to increase vehicle fuel efficiency by nearly 50 percent over the next 15 years.

The bill, introduced more than a year ago by Sen. Richard H. Bryan (D-Nev.) as a clean air measure, now appears to have a good chance of enactment by the Senate as a fuel-conservation bill. But the bill is strongly opposed by the auto industry, and its prospects in the House are much less bright.

In addition to mandatory increases in auto mileage efficiency, the environmental and conservation groups have endorsed measures such as a new tax on "gas guzzler" vehicles, the use of domestically abundant fuels such as natural gas for buses and fleet vehicles and a broad-based energy tax to discourage consumption.

But the Bush administration, which is in the final stages of preparing a comprehensive national energy policy, will not now support any conservation measures that require legislation, Energy Secretary James D. Watkins said.

The administration also has declined to open the 590-million barrel Strategic Petroleum Reserve to make up some of the oil lost to world markets by the shutdown of Iraqi and Kuwaiti production.

At a news conference yesterday, Bush issued a matter-of-fact call for energy conservation, but he said the country is not facing an energy emergency and Americans should not cancel their vacations to save gasoline. "I'm not going to stop using my boat," he said.

Conservation measures such as increased auto mileage would have no impact on the current crisis, in which about 9 percent of the non-communist world's crude oil supply has suddenly been removed from the market. But supporters say they would insulate the country from future price shocks and supply disruptions.

Bryan's measure, for example, could reduce oil demand by 2.8 million barrels a day when fully implemented, according to calculations by the American Council for an Energy Efficient Economy. The United States imported nearly 9 million barrels a day in July, or 51.3 percent of its total supply.

Under current law, automakers are required to produce vehicles that average 27.5 miles per gallon. Each company must sell enough smaller, lighter cars that meet or exceed the standard to balance the big cars that do not. This standard, known as the corporate average fuel economy (CAFE), has not been raised since 1985.

Bryan's bill would raise the CAFE standard by 20 percent in 1995 and would set it at 40 miles per gallon by 2005. It was approved by the Senate Commerce Committee by a 14-to-4 vote in April and is expected to come up for a vote of the full Senate in early September.

Auto industry lobbyists and environmental groups say there is much less support for a parallel bill in the House. It has been stalled in the Energy and Commerce Committee, whose chairman, Rep. John Dingell (D-Mich.), is widely assumed to oppose it, though he has not said so publicly.

"Dingell can bottle it up, but in this crisis he may buckle," said Christopher Flavin, a vice president of the Worldwatch Institute. "I think it's going to be a whole new ballgame."

Representatives of the automobile industry say it is technically feasible to produce cars that get 50 miles to a gallon -- a few already do -- but they say consumers don't want them, and in any case Bryan's bill would save less energy than advertised because it would apply only to new cars, not the existing fleet.

Robert Liberatore, chief lobbyist for Chrysler Corp., said Bryan's bill, "while well-intentioned, won't work. ... The market today is full of very fuel-efficient cars. You don't need a law to require that people buy them. You need an economic incentive, such as higher taxes on gasoline."