Until recently, the number John Bitango knew best was 3.785. The young Bethesda gas station operator had been dividing liter totals by that number, to turn them into gallons, since his station went metric five years ago.

He thought that customers would learn the system. Instead, they muttered "What the hell does this mean?" he said. Three weeks ago, Bitango put new mechanisms in his pumps at Dale's Sunoco and started measuring out gas in gallons once again.

Like mechanics and other workers, Bitango is caught in a silent war against pounds and ounces, feet and inches, gallons and pints, and other conventional U.S. measurements. It is a war that pits a recalcitrant United States, Burma, and Brunei, a sultanate of about 50,000 persons on the coast of Borneo, against the rest of the world and more than 95 percent of its inhabitants.

Not surprisingly, the rest of the world is winning. This country's big auto companies, for instance, are quietly going metric largely because their overseas plants, suppliers and customers demand it. Bitango can measure his gas in gallons, but it is pumped into gas tanks that are calibrated in liters. He must sell metric windshield wipers and work with metric tools.

"I've got metric everything," Bitango says. "Metric socket wrenches, metric box wrenches, metric allen wrenches. From a service station's point of view, you have to double your tools or you will lose. If it's metric, I have to have it."

Few people realize the growth of the metric system that has taken place since Congress passed the Metric Conversion Act of 1975.

A U.S. Department of Commerce study had recommended that Congress legislate a 10-year transition period. But Congress did not follow that recommendation. Instead, the act declared that "the policy of the U.S. shall be to coordinate and plan the increasing use of the metric system in the United States." Thus, the transition became voluntary, unlike in Britain and Canada, which went metric by legislative decree.

The result, in part, is that more than 95 percent of General Motors cars and parts are measured in metrics, as are more than 50 percent of the parts in Chrysler and Ford cars.

Few people stop to think, either, when they pour a shot of scotch, that it is coming from a metric bottle. The U.S. wine and liquor industry went completely metric by 1980.

"Most people aren't measurement-sensitive," said Cheryl Cummins, vice president of the American National Metric Council in Bethesda, a private organization with 600 members, most of whom are large corporations.

The council was formed in 1973, two years after the Commerce Department recommended that the country switch to metrics.

The council, which has more than 600 members but a full-time staff of seven persons, sponsors committees and workshops covering more than 50 industries. It collects information on metric transition and passes it on to industries.

Recently, for instance, the council organized seminars on the use of metric measurements in industrial fasteners -- the nuts, bolts and rivets that hold things together. With council members such as the John Deere Co., the tractor and agricultural machinery manufacturer, and General Motors, both of whom went metric in the 1970s, it was able to find people to relate their experiences with metric.

During these seminars, some manufacturers complained that it was difficult to find fasteners to use with their metric products. As a result, the council is considering creating a Fastener Sector Committee to help industries wanting to manufacture metric goods find fastener makers and distributors who can give them metric fasteners.

What the law cannot do to move metrics along, however, economics may. Member nations of the European Community, for example, have said they will accept only metric imports after 1990, according to G.T. Underwood, director of the metric programming office of the Commerce Department. "Nonmetric goods are becoming increasingly unwelcome in other countries, because it means they have to put up with an oddball system," he said.

The U.S. wine and liquor industry went metric largely because it was seeking new international markets. New, individually packaged soft drinks in foil pouches are in metric sizes because the technology used to make them came from Europe.

Soft drinks are increasingly sold in half-liter, liter and two-liter bottles because companies anticipated that this country would go metric in the long run and did not want to have to build new machines later on.

Similar considerations have meant that U.S. tires are being sold in metric sizes and that the U.S. computer industry is increasingly metric, as are the electronics and lumber industries. Between 1978 and 1982, the percentage of hand tools sold in metric sizes increased from 10 to 25 percent, according to the council, largely because an increasing number of cars are made to metric specifications.

Still, the language most U.S. consumers speak is feet and inches, pounds and ounces. "I don't see anyone out there buying measuring cups in milliliters rather than the old cups, pints and quarts," says Carroll Brickenkamp, adviser to the National Conference on Weights and Measures. "I don't see anyone buying metric rulers. I don't see people in Sears buying steel measuring tapes that are even dual measurements."

"There aren't that many metric packages that we have in our stores," says Odonna Matthews, consumer adviser for the Landover-based Giant Food grocery chain.

Giant has been labeling its own brands in both metric and conventional U.S. figures since the mid-1970s, she said. "We initially felt that the U.S. was going into metric more quickly than it has," she said.

Metric measurements that would touch citizens most directly -- on road signs, thermometers and in shops -- will be the last to change, predicted George E. Carleton, a manager with the Procter & Gamble Co. About 60 percent of supermarket goods display metric and conventional U.S. sizes, he said, but only 10 percent of these goods are measured in "hard" metric sizes, such as 500 grams. Most are simply translations of conventional measurements, such as 453.6 grams, which equals one pound.

Customer reluctance to accept metric, he said, explains why the detergent Mr. Clean is made in a 32-ounce bottle (one quart) in the United States but in a slightly larger one-liter bottle is Europe. Even the American bottle is designed metrically, he said, and then reduced to quart size. "We design all our bottles in the metric system and always have," he said, "simply because it's easier to work with than the inch-pound system."

So for the time being, at least, the country is yielding to metric with difficulty. "You evolve into metric," said Underwood of the Commerce Department. "You ooze into it . . . . "

Bitango, fresh from his experience of selling gas metrically, agrees that it will be some time before the public learns to love liters. "Maybe in three to four generations," he said.

Until then, he foresees he will be pouring oil from quart-sized cans into metrically measured cars and finding that it doesn't fit. "When you do an oil change," he said, "you have about three-quarters of a quart left over, sitting on the shelf. It won't hold it."