The Mitsubishi name appears on sneakers, banks, personal computers, a brand of canned tuna, shirt-pocket telephones, little sedans for the light of income and large coupes for the heavier of foot.

Now Mitsubishi--not the seafood or sneaker company but the Tokyo firm that has engineered reliable, good value cars since its own Model A of 1917--joins Lexus-Toyota, Infiniti-Nissan and Honda-Acura to complete the first quartet of Japanese luxury cars.

Not that the 1992 Mitsubishi Diamante, despite the sparkle of its name, is luxurious in line with the Michelin Guide or vicuna bathrobes. It's more of a near-luxury car. Or, if you'll forgive a fashionable conflict of adjectives, an affordable luxury car.

It's what you buy when you want walnut, full leather and V-8 power but an equity loan officer advises injected plastic, Leatherette and four cylinders. Like the BMW 318i. Call it entry level from the mezzanine floor. Like the Mercedes 190.

Discount luxus is almost the look, most of the feel and some of the spirit. Without much of the cost. Like the junior Lexus 250 and the mini Infiniti M30.

Above all else, cars like this Diamante LS (and the soon-to-be-sold Acura Vigor) are an offering in automotive self-indulgence--without the gas guzzler and luxury taxes attached to many of the beautiful and big-engined motorcars that cost $30,000 and more.

Consequently, a significant question forms after several days of enjoying Diamante's ample quality and middling aloofness: Are the big and the luxurious top dogs of Lexus, Infiniti and BMW actually worth an additional $15,000. Or more?

The answer: We think not. Except maybe to those who bray about wealth, status and college transcripts.

The affordable luxury lot is becoming a rather cluttered class these days. Yet it is a crowd where the Diamante will stand out on two counts:

With an entry-level version selling for $20,495 and the up-market LS starting at $25,135, the Diamante offers competitive pricing and value. Especially at the top end, which includes anti-lock brakes; driver's side air bag; power seats; cruise control; automatic air conditioning and just about every feature short of power sunroof, CD, leather seats and some suspension trickery.

Technologically, a fully optioned Diamante is the cutting edge of its class. There's traction control to tame over-steer--the rear end swinging out in a skid. Also a second system to neutralize under-steer--a loss of front-wheel grip and directional control caused by too much forward motion while cornering.

Then there's twin-spray fuel injection, an electronically controlled suspension monitoring road surfaces and ride, a microprocessor managing the ignition for optimum fuel combustion. . . .

Such gadgetry, of course, will find enormous favor among the lethargic who consider pointing a car in the right direction to be spiritual rush enough. As the vehicle is only available with automatic transmission, Mitsubishi must be anticipating that these less-physical types will form the majority of Diamante buyers. So be it.

But some of us dweebs still think man should be master of his machinery. The thought of unseen forces and electronic impulses controlling the acceleration, balance and cornering performance of a car is a hanging offense somewhere between day-old jelly doughnuts and Satanism.

Automatic transmissions--where gearshifts affecting the balance, weight and geometry of a car are largely beyond our control--are bad enough. But add a system that backs off the power under even undramatic cornering loads and the sensation is downright uncomfortable.

Several times we tried to throttle steer and power the Diamante out of some serious corners. Every time the microchips shook their little fiber-optic heads and countermanded our orders to the engine room.

On the other hand, all this gray magic is optional. You can take it or leave it. Or buy it and cancel it out with a kill button on the console. The feeling is omnipotent.

We did, however, like another portion of the car's curiously named Euro-handling package (Europeans, presumably, will be offered an Amerigo-handling package) which tells the fully independent suspension system what to do.

It senses the attitude and dynamics of the car in all its configurations in motion, automatically adjusting shock absorbers and helping them soak up lumps and thumps. It also adjusts a spare set of springs that tense the platform (adapted from Mitsubishi's 3000 GT) and minimizes roll, pitch, bounce, squat and dive that occur while braking heavily, cornering hard or leaping potholes.

Another feature is ride height control. Mitsubishi says it comes into play at speeds approaching 60 m.p.h. and supposedly lowers ride height by about 0.4 inches. We found no successful way of leaning out of a window and measuring this. Nor did we find it improved stability and aerodynamics worth a durn.

Aesthetically, the roll of the Diamante's roof-line and the ratio of lowered hood versus raised trunk, gives the car a coupe's flow and compactness. Although those four doors are broad and useful enough.

The flanks and rear deck of the car are balanced between pleasance and purpose, although quite reminiscent of the Mitsubishi Galant. The front, in silhouette, unfortunately looks very much like a BMW with an under-bite.

Overall, however, there's a gloss to the finish, reduced tolerances to the fit and a solid look to the five-spoke wheels (standard on the LS) that says this is a car to please both discerning drivers and Ritz-Carlton doormen.

Power on the base model comes from a 12-valve V-6 that produces 175 horsepower. Docility must be presumed. The LS is driven by a more powerful engine (202-horsepower from a 24-valve V-6), which is quite enthusiastic in traffic, lithe when running free but certainly no firecracker.

Blame some of that on the fact that the weight of the Diamante LS is horribly close to the Buick Park Avenue. Then there's the sloth--even featuring power and economy settings--of the automatic transmission.

On an engine this size, an automatic transmission soaks up gobs of power that a manual five-speed would ship to the driving wheels. That adds about 2 seconds on the acceleration time from zero to 60 m.p.h. In the case of the Diamante, that's more than a 20% acceleration loss.

Internally, the LS in Diamante LS must stand for Looking Slick. Or Luxurious Stuff. The dash is a smooth, single undulation rather than the standard complex of dents and curves. This is a cockpit all right, with the line of center arm rest and console moving forward and swooping around to encapsulate both front seats.

The leather seats are supple at rest, firm when their occupants are belted in and the going gets fun. The stereo system is sophisticated with six speakers, graphic equalizer, surround sound and a dedication to dragging the best from big bands and Eric Clapton.

Despite the driver's-side air bag, Mitsubishi has found sufficient spare room on the steering wheel hub for a separate set of radio controls.

Cute, tiny touches abound. Doors automatically lock once the speed of the car exceeds 15 m.p.h. Heater ducts go to the rear seats. On doors and dash there are rich, deep gloss, accent strips you'd have to drill to find out they're not real wood.

Clearly the quality mounting of a five-carat Diamante.

1992 Mitsubishi Diamante

The Good Electronics take the worry out of handling. Quality appointments, first-cabin feel. Smoothness and grace at pace. Delightful interior. Manageable price.

The Bad Low-end performance. Familiar silhouette of Galant.

The Ugly Front-end under-bite.

Cost Base: $25,135. As tested: $30,395 (includes power sunroof, CD player, Euro-handling system, leather seats, cruise control, automatic air conditioning).

Engine 24-valve, 3.0 liters, double overhead cam V-6 developing 202 horsepower.

Type Front-drive, four-door, semi-luxury sedan.

Performance 0-60, as tested, 9.1 seconds. Top speed, 128 m.p.h. Fuel consumption, EPA city-highway, 18-24 m.p.g.

Curb Weight 3,505 pounds.