The Lincoln influence is rubbing off on the Mercury Grand Marquis.

Buyers of the 1992 Grand Marquis just arriving in dealer showrooms will find its outer styling reminiscent of the popular Lincoln Continental. Gone is the square-cornered, boxy Grand Marquis. In its place is a Grand Marquis with sloping front hood and gently rounded rear.Under the Grand Marquis hood is a new modular engine. It's the same V-8 that debuted last fall in the Lincoln Town Car.

The frame, too, is that of the Town Car.

Ford Motor Co., which makes both Lincoln and Mercury cars, is betting that buyers of its traditional full-size Grand Marquis and sister car, the Ford Crown Victoria, will enjoy the first major design changes in 12 years.

"People who were buying the car said, `Why change it?' " said Lincoln-Mercury spokesman Chuck Snearly.

"We felt we had to. We wanted it to be more fuel-efficient. We wanted to update the ride and appearance. Also, when you do something over again, you can improve the quality.

"We think we kept the things that the people who buy it want," Snearly said.

The test car, a Grand Marquis LS, was a pleasant mix of traditional big-car ride and improved handling. It was a cushioned ride, and there was some body sway on curves. But overall the new Grand Marquis held its place on the road quite well - thanks to the addition of a rear stabilizer bar - while not jostling passengers.

The speed-sensitive variable assist power steering worked so well the steering wheel seemed to glide around in turns.

The engine, a 4.6-liter overhead cam powerplant, is smaller than the previous 5-liter Grand Marquis engine, but provides 40 more horsepower - 190.

It was paired with a standard four-speed automatic transmission and sipped the gas in pedal-to-the-metal driving, getting about 19 miles to the gallon. The car provided a restful, easy ride - one that's sure to be popular with the average buyer, who the company says is between 55 and 65 years of age.

Between 70 percent and 80 percent of buyers are men and median household income ranges from $40,000 to $50,000, according to Lincoln-Mercury.

The new design is slightly roomier. Headroom in front is up 1.1 inches from the previous model's 38.3 inches. Front hiproom has grown 1.4 inches, to 59, to help accommodate three passengers on the flat, spacious seats.

In the rear seat, I could extend my legs and not hit the front seat-backs, even with the front seats all the way back and reclined some. Rear hiproom has grown 0.7 inch, and rear headroom is up nearly an inch from the previous model.

But the middle passengers in front and back must sit over the rear-drive hump.

Even though fuel economy has improved, the Grand Marquis gas tank has expanded from 18 to 20 gallons for extended range.

The trunk, with 20.6 cubic feet of luggage space, is deep and remains one of the biggest of any full-size auto. It's designed so you don't have to lift items up over the car body.

The dashboard was appointed with digital gauges and many of the buttons and knobs were large and easy to reach, especially the buttons to open the trunk from inside and unlock the fuel filler door.

The test car included soft leather seat trim, a $555 option. Another nice touch is a delay switch to automatically shut off headlights a few moments after the ignition was turned off.

The test car, an LS sedan, had a base price of $19,789 compared with the Buick Park Avenue, with V-6 engine, at $24,385; Chevrolet Caprice, with V-8 engine, at $16,515; and the Oldsmobile 98 Regency, with V-6 engine, at $23,695.

*****

(Additional information)

1991 Mercury Grand Marquis LS

BASE PRICE: $19,789.

AS TESTED: $25,225.

TYPE: Front-engine, rear-drive, six-passenger, full-size sedan.

ENGINE: 4.6-liter, fuel-injected V-8.

MILEAGE: 18 mpg (city), 25 mpg (highway).

LENGTH: 212.5 inches.

WHEELBASE: 114.4 inches.

CURB WT.: 3,768 lbs.

BUILT AT: St. Thomas, Ontario, Canada.

OPTIONS: Preferred equipment package (includes cruise control, illuminated entry system, bodyside paint stripe, power door locks, floor mats, aluminum wheels, power radio antenna, leather-wrappped steering wheel) $2,199; leather seat trim $555; keyless entry system $137; electronic group $516; six-way dual power seats $489; antilock brakes with trac assist $1,035; high-level audio system $335; rear air suspension $285; less option package discount of $650.

DESTINATION CHARGE: $535.