The flurry of new models from Buick in the last few months now makes the LeSabre one of the oldest in its product line even though it got a modest restyle last year. Yet it remains Buick's bread-and-butter car because it has been the best-selling full-size sedan for four years.

It also scores well in the J.D. Power Initial Quality Survey.

The Park Avenue, Century and Regal_all new since last fall_are outstanding additions for Buick because they are solidly built and packaged well. They move the product line forward dramatically, and make the LeSabre's age more evident.

Nevertheless, LeSabre lovers will be happy to note that the recent styling updates will carry it forward for the immediate future. The fixed-lens headlights with adjustable reflectors have a jewel-like look, and the grille has been tidied up, too. It is still recognizably a LeSabre. Cleaner fascias front and rear, plus wider, smoother side moldings, contribute to the general smoothing up of the exterior.

There are two trim models, Custom and Limited, and I drove the Custom. Its basic structural underbody, or platform, is shared with the Pontiac Bonneville and Oldsmobile Eighty-Eight. It has a 110.8-inch wheelbase, which gives room inside for six passengers in a pinch, although five is the more practical limit.

These front-wheel-drive sedans all share GM's 3800 Series II 3.8-liter V6. While this engine shuns overhead cams and multi-valve cylinder heads in favor of a simpler layout, it performs well. It cranks out 205 horsepower, which is more than enough to give snappy acceleration and yet get decent fuel economy. It is rated at 30 mpg on the highway.

Wards Auto World, an industry trade publication, rated this engine one of its Ten Best in 1996. Coupled to a four-speed automatic transmission, the only one available, it goes about its work without drama. Much of its smoothness can be attributed to the way the transmission and engine interact to take the jolt out of shifts.

Some jolts from the road, however, are easily felt, which is evidence that the basic structure is ready for the same kind of redesign that has been done on the Century and Regal. Both of those cars do a much better job of isolating passengers from the road without degrading the handling.

Inside, the LeSabre's age also shows in the layout of the instrument panel, which has tiny, round gauges scattered across a dash originally designed for digital gauges. The analog instruments are easier to read at a glance; they just don't fit the space as well.

The dashboard curves across the front of the passenger compartment and blends into the doors. In an unusual arrangement, the headlight switch is mounted on the edge of the door.

The radio is a combination of large, simple knobs and tiny buttons. Supplemental controls on the steering wheel were a welcome option.

The automatic climate control is simple and compact, and takes up little space beneath the radio, but it would be easi er to use with rotary controls.

For a car that is likely to be bought by older buyers whose eyes may not be as good as they once were, the outside rearview mirrors are way too small. I found that they restricted my view.

Our test car was equipped with the optional Gran Touring package consisting of a 3.06 axle ratio, touring suspension, 16-inch tires and aluminum wheels. While this suspension offers better road feel and control than the base suspension, it suffers from what I call the GM paradox: It is rough over little bumps at slow speeds yet too soft on the highway.

All LeSabres have air conditioning, anti-lock brakes, dual airbags, power windows and rear-window defogger.

Our test car's base price was $22,015. It was equipped with cruise control, power locks, analog gauges, AM//FM stereo with concert sound and remote steering wheel controls, compact disc player, traction control, Gran Touring package, aluminum wheels, power driver's seat, power rrors, keyless remote and floor mats.

The sticker price was $25,475.

The basic warranty is for three years or 36,000 miles, including roadside assistance.

Point: The revisions to the LeSabre's styling improve its looks without changing its basic character. The 3800 engine revs willingly and the transmission is smooth.

Counterpoint: The rear-view mirrors are too small and the ride lacks the suppleness found on the Regal and Park Avenue.

ENGINE: 3.8-liter, V-6
WHEELBASE: 110.8 inches
CURB WEIGHT: 3,441 lbs.
BASE PRICE: $22,015
MPG RATING: 19 city, 30 hwy.