Beneath the Cutlass Ciera hood purrs a smooth-running diesel

You can almost forget it's a diesel, the car is so quiet and the performance that good.

Indeed, the Oldsmobile Cutlass Ciera -- the only Cutlass with front-wheel drive -- with a brand-new 4.3-liter, V-6 diesel engine beneath the hood, a $775 option, is remarkably perky on the road, just about as responsive to driver input as a motorist might expect from a gasoline-engine car.

The Oldsmobile engineers, in fact, have succeeded mightily in reducing the inherent roughness of a diesel in the new V-6. By using special energy-absorbing engine mounts, they have even further isolated the passenger compartment from the noise and vibration beneath the hood. The result: a reallym quiet ride despite the oil burner up front.

The Cutlass Ciera LS diesel automobile, which weighs just under a ton and a half, is the Oldsmobile division's version of the midsize A-cars introduced by General Motors last fall.

It is some 600 pounds lighter than the rear-drive Cutlass Supreme and 150 pounds lighter than the X-car Omega.

Base-priced at a little over $9,000, the car I test drove was jammed with more than $3,500 in options -- everything from the usual power aids to a power antenna ($55), tilt-away steering wheel ($95), and front and rear mats ($25 and

Thus, the inside environment was as ''comfortable as home.'' At the same time the car did what it was designed to do under way.

Yet while the Ciera was fun to drive, it is no BMW -- nor is it supposed to be one. Handling and cornering were somewhat compromised because of the too-soft suspension of the car. Even so, many people prefer a soft ride so the judgment depends on who is inside the car.

The climate-control system, while expensive, does its job well.

As for m.p.g. on the road, the Environmental Protection Agency lists the Ciera at 44 on the highway and 27 in the city. The high figure is probably just thatm -- high.

What lingers long after the car has gone back to GM is the engine. Is it worth the money? That's a decision only the motorist can decide. With the oil-burning engine list-priced at nearly $800, it may take a long, long time to recoup the money in fuel saved. Even so, it's one of the finest diesel engines around.

And that should count for a lot.

Oldsmobile is marketing a broad array of its successful Cutlass models in 1982, including both rear-drive as well as the new front-drive Ciera. All of them, according to Robert J. Cook, the division's general manager, are Cutlasses.

''Having both allows us to create a family of Cutlass that expands the customer's alternatives and the appeal of Cutlass,'' he says.

Apparently, what Detroit needs is a lot more success stories like the Oldsmobile Cutlass nameplate.