Can bullet train win hearts of car-loving Californians?

It makes an alluring rival. It has both a futuristic glamour and a nostalgic charm. But before the bullet train planned for southern California can pay its way, it'll have to break up the Californian's enduring love affair with the automobile.

Specifically, the company backing the bullet, American High Speed Rail Corporation, will have to convince the nation's financiers that a Japanese-style 160 m.p.h. train linking Los Angeles and San Diego can win travelers from behind the wheel.

If it succeeds, the train could be the beginning of what some foresee as a rebirth of medium-distance rail travel in this country.

Interest in high-speed passenger trains has been on a crescendo since around 1975, when the Ohio Rail Transportation Authority was formed in the wake of the Arab oil embargo. It determined there was a need for a passenger rail system, but only if it was considerably faster than car travel.

In 1981 two Amtrak executives, Alan Boyd and Lawrence Gilson, took the entrepreneurial leap. They had been investigating how to revive the manufacture of railroad rolling stock in the US, and their research led to a decision to form American High Speed Rail Corporation and build a bullet train.

The corridor from downtown Los Angeles to San Diego, with a jog over to the L.A. airport, was found to be the most promising in the country. It was long enough to use the train's speed, short enough to be cheap, all in one state to simplify the political and regulatory road clearing, and increasingly congested with auto traffic.

State approval was needed before the company could raise money by issuing tax-free bonds. But the Legislature made short work of that last September. The new firm was given the OK to raise up to $1.25 million, and was exempted from some of the environmental studies that state law would ordinarily require.

The bullet train's political appeal - in this state as elsewhere - lies in the number of new jobs construction would generate and in the number of permanent railroad jobs the system would sustain, in this case around a thousand. And all at no financial obligation to the state.

American High Speed Rail hopes to find an American manufacturer to build the rail cars from the Japanese General Railways blueprints. Otherwise, they will buy the rolling stock ''off the shelf'' from the Japanese.

Meanwhile, seaside communities along the planned route have begun to protest the possibility of a noisy invader passing every 10 minutes on an elevated track. But that is not the steepest grade this potential first American bullet train will have to climb.

The train must be paid for. The original cost was pegged at under $2 billion, but some transportation experts would double that estimate. The company is putting together its financing plan now and anticipates seeking investors in late summer or early fall. The cornerstone of the plan is a commitment from the Bank of Tokyo to provide a quarter of the project's cost.

The credibility of the whole scheme, for investors, will ride on estimates of how many people will get out of their cars and pay $60 for the round trip by train.

''The dominant mode of transportation in southern California will always be the automobile,'' says Mr. Gilson, president of American High Speed Rail. ''We're not trying to do anything magical here. We just want a relatively minor percentage of the trips. We think (the train) has a place for the time-sensitive traveler, and that's who we're aiming for.''

It takes roughly 21/2 hours to drive the 110 miles from downtown Los Angeles through Orange County to San Diego. By the end of the decade, state transportation officials expect throttled traffic to slow it to 31/2 hours.

The bullet train would make the run in 59 minutes, and in the smooth comfort bullet trains are noted for. A study by the consulting firm of Arthur D. Little Inc. commissioned by American High Speed Rail estimates that the train could win over 20 percent of the corridor's trip traffic.

Skeptics, such as Roger Teal, a transportation analyst at the University of California at Irvine, consider the data flimsy.

''The places where rail is successful is in densely populated, concentrated urban centers with well-developed transit infrastructure,'' he says. L.A. and San Diego don't fit that bill.

Says Dr. Teal, ''If I believed that these people could finance this thing privately without any public help, I'd be leading the cheers. But I consider that about as likely as the sun rising in the West.''

His concern, widely shared, is that once the bullet train is built, it will follow Amtrak's lead, fail to turn an operating profit, and become a financial ward of the state.

On the other hand, Gilson says, ''Some New York advisers think we may have been too conservative'' in estimating ridership.

The whole debate becomes one between those like Dr. Teal who see rail as a thing of the past, noting that even Europe is turning steadily to the car, and those who see the train, and particularly high-speed rail, as a way out of the energy-hungry car.

There is already another bullet train in preliminary planning stages here. It would link Los Angeles to Las Vegas by a 250 m.p.h. electric train that would float an inch above its rails by magnetic levitation - no friction. This would be the world's first ''maglev'' train outside of test projects.

In Florida, a high-speed rail link has been proposed between Miami, Orlando, and Tampa. In Texas, a Dallas-Houston-San Antonio line is under study by the state. A Pennsylvania commission is reviewing the Pittsburg-Philadelphia corridor. Various proposed routes extend from Chicago.

There was wide support in Ohio to begin a high-speed network in the ''Three C Corridor'' between Cleveland, Columbus, and Cincinnati. A 1-cent boost in the sales tax there would have launched the project, but recession-weary voters spurned the tax last fall.

Five states of the upper Midwest belong to the High Speed Rail Compact, an alliance drawing bigger attendance to its meetings every year.