Nissan Motor Corp., U.S.A., shifts gears tomorrow.

It officially debuts the new 1995 Nissan 240SX coupe, with the company embracing a different philosophy.

The image of a car for road racers is being played down, and the company instead is introducing a sports coupe designed more for maturing baby-boomers.

Introduction day could be hit-or-miss for Indianapolis Nissan dealers, as a company spokesmen said he was still checking on when cars were to be shipped. Prices also aren't available until tomorrow.

"So far I don't have a car," Collins Nissan general manager Jeff Drake said last week. "And they haven't told us anything on price."

The 1995 coupe retains the performance characteristics of its predecessor, with driving enjoyment the guiding principle. The classic front-engine, rear-wheel-drive sports car configuration is retained. But the coupe is aimed at a more mature buyer.

According to Jerry Florence, Nissan's vice president of marketing, buyers of the new 240SX are more likely to be female, well educated and have an above- average annual income.

Thus the new coupe dotes on responsive performance rather than just raw horsepower. There is still plenty of that, but comfort and convenience are of primary importance.

The new SX comes in two models, the standard 240SX and the more upscale 240SX SE. Both carry the same mechanicals and comprehensive array of standard equipment and safety features.

By going upstream to an SE, you pick up features like air- conditioning, deluxe stereo, power and a variety of convenience items.

The 1995 240SX continues a long line of distinctive Nissan sport coupes that date back to the original 240Z in 1969. And with its aerodynamic exterior, styling is evolutionary, with flowing lines that express roundness from front to rear.

The shape was enhanced by extending the wheels out toward the four corners of the car. This creates a wider track for a more stable platform, and makes maximum use of the coupe's 50 percent increase in torsional rigidity and 100 percent increase in bending rigidity.

The suspension has all four wheels independently sprung with multilink components and coil springs. This measurably enhances rear-wheel grip over the more common live rear axle and rigid housing.

This suspension has been modified to give a softer ride than the car's predecessor, but it still retains traditional sports-car control.

The 240SX's engine is Nissan's tried-and-proven 2.4-liter (145.7 cubic inches) dual overhead cam, 16-valve four-cylinder. Its 155 horsepower and 160 foot-pounds of torque are the same as the 1994 version, but the motor has been modified to offer improved torque in the low-to-mid-speed range.

It was the feeling of Nissan's engineering people that this is where the majority of driving is done, and they wanted smoother acceleration.

The 240SX has quite good, if not barn- burner, acceleration.

With the coupe aimed toward a little older audience, estimated 0-60 miles an hour tim es are in the 8 seconds bracket. Top speed is about 130 mph, and that fits right into Nissan's marketing strategy.

The driver wheeling one of these coupes will find the cockpit pretty much state of the art.

A four-gauge instrument panel lies directly ahead of the driver, with tachometer to the left and speedometer to the right. These two central instruments are flanked by a heat gauge, left, and fuel gauge, right.

Console-mounted shift levers and temperature and stereo controls are in conventional central locations.

I would have liked to see an oil-pressure gauge, especially with the five-speed manual gearbox that is the standard transmission in both the SX and SX E models. But one isn't included.

Nissan's 1995 240SX falls into a specialty-car segment of the market. With the new model, the coupe will serve more than one type of owner.

1995 Nissan 240SX Base price: Not yet available.Type: Front engine, rear- drive, four-passenger sport coupe. Engine: 2.4 liters, DOHC inline 4, 16 valves, fuel-injected, 155 horsepower, 160 foot-pounds of torque.Transmission: Five-speed manual.Acceleration: Estimated 0-60 mph in 8.4 seconds.Top speed: Estimated 130 mph.Mileage: 22 mpg city/28 mpg highway.Wheelbase: 99.4 inches.Length: 177.2 inches.Width: 68.1 inches.Height: 50.8 inches.Curb weight: 2.753 pounds.Options: Air conditioning, deluxe stereo, automatic transmission, leather, ABS braking, limited-slip differential, power locks, cruise control, power sun roof, aluminum alloy wheels.