Leave New York for Washington? Never, said 60-year-old Richard Roche. He'd rather retire.

Then, his boss began talking up the joys of life in the nation's capital. Not museums, the mall, parks, or being near the center of power. But the things that count to a corporate executive like Roche: interest-free auto loans, an 8.5 percent mortgage, and an 11.5 percent loan to anyone willing to buy your old home.

Thanks to inducements like those, and more, 800 New York employes of a major Mobil Oil Corp. division have given up Gotham for jobs at the division's new glass-and-steel headquarters along the Capital Beltway in Fairfax County.

Mobil executives won't say how much the move is costing the corporation, but the high cost of money and inflation clearly have boosted the total into the millions of dollars, forcing the firm to give its workers benefits many never imagined when they signed up to work in Mobil's 42nd Street headquarters in midtown New York.

"If Mobil had not supported us we would never have moved," said Roche as he and his wife sat in the den of their new $140,000 two-story colonial home outside Fairfax City, warming themselves by a roaring fireplace.

The low-interest mortgages were just the beginning. Workers who didn't have autos were offered free driving lessons. Three free round-trip house-hunting visits to Washington were added along with a month of extra pay for workers willing to make the move south.

To Mobil, the incentives were essential. Without them, especially the decision to subsidize mortgage costs, the move "would have been a disaster," according to Robert Stahl, a consultant hired by Mobil to assist the transition. Many oil company workers were reluctant to make the move because home mortgage rates had jumped so high since they had purchaed their homes in the New York area, he said.

Sure, the corporation had to "entice people to come down," said Donald Jeschke, personnel manager at the Mobil division. "We had an ongoing operation and if you lost a large segment [of workers] it would have been difficult to replace them and operate at the same level of efficiency."

As it turned out three of four workers in the company's U.S. and refining division took Mobil up on the offer and made the move to Northern Virginia in one of the largest office transfers in the state's history. "We continued operations without a hitch," said Jeschke.

While federal workers, who compose the bulk of Washington's workforce, probably would never dream of such benefits, they are becoming increasingly common in private industry, according to Mobil executives and many personnel experts. "It's impossible to accomplish a group move without a mortgage differential because people are trading a low mortgage for a high one when they move," noted moving consultant Stahl.

The newly arrived Mobil workers, who could have been faced with home mortgages with interest rates as high as 16 percent, agree.

"Mobil made it possible for us to buy this house, most definitely," said 29-year-old Rose Guinan, a secretary in the company's planning office who exchanged a three-bedroom apartment in Queens for a $75,000 four-bedroom white stucco house in Annandale. "It seemed too good to be true . . . that we were buying a house in a nice neighborhood."

The Mobil transfer was something of a bonanza for Northern Virginia's hard-pressed real estate industry, also hurt by high interest rates. More than 600 of the 800 transferred employes bought homes and almost 400 of those bought new homes, Stahl said.

"January, February and March were just horrendous across the county because that's when interest rates peaked, but that's where Mobil's people were buying," said one real estate official in Fairfax. "They [the Mobil employes] helped dampen the effect of the downturn. It would have been worse if they had not arrived at that time."

Mobil, the nation's second largest oil company, declines to reveal specifics of its moving costs, but consultant Stahl notes that a corporation with a policy like Mobil's will typically spend $25,000 per worker just to pay the moving expenses and closing costs on the old and new homes for each employe. Those costs alone for Mobil's 600 workers who bought homes would be $15 million.

Whatever it cost, Mobil's Guinan says her reaction can be summed up in two words: "Just fantastic."