1998 Pontiac Grand Prix

This is a Pontiac Grand Prix offered with high-performance packages from the SLP Automotive Group. SLP is based in Troy, Mich., and works with General Motors to offer a variety of customized GM autos such as the Chevrolet Camaro SS and Pontiac Firebird Firehawk.

The new, nationally available GTX Ram Air is the most practical GM model with SLP input because the mid-size ``Prix'' is roomy and refined.

It would not be financially feasible for major automakers such as GM to offer relatively small numbers of customized cars. So they let savvy independent outfits modify those cars because it enhances brand appeal. The cars are sold through an automaker's dealer network.

Companies that modify cars with such things as aftermarket packages long have been common in Europe, where they are known as ``tuners.'' They've thrived because some people never are satisfied with new factory models and always want more power and racier appearances.

The same situation exists in the United States. Remember the special custom Mercedes models with monochromatic paint on the old ``Miami Vice'' television series? They came from an independent German tuner outfit called AMG, whose U.S. operation was based in west suburban Westmont.

The GTX Ram Air package is offered for all Grand Prix SE and GT models--and for the Grand Prix with the factory GTP performance option. Grand Prixs range in price from $18,795 to $22,125, while the GTP package costs an extra $1,610 for the GT.

Modifications from some tuner outfits actually can equal the price of the new car being customized. But the base GTX Ram Air package has a $2,499 base price and is covered by SLP's three year/36,000-mile warranty, as are other SLP options.

The GTX Ram Air features a composite hood with two prominent air scoops, an under-hood forced air induction system, special exterior badges and key fobs.

The more air rammed into engine cylinders, the higher the horsepower. Thus, those hood scoops and induction system increase the horsepower of the 3.1-liter stock Grand Prix V-6 from 160 to 165--and add 10 horsepower to the 3.8-liter V-6; it produces 195 horsepower--or 240 horsepower with the GTP package.

Want even more power? SLP offers a $799 Performance Exhaust System that adds an additional 10 horsepower to GT and GTP Grand Prix models with the 3.8 V-6. It consists of a stainless steel exhaust system with dual outlets and four exhaust tips, with freer-flowing mufflers that emit a more aggressive exhaust note.

How about sharper handling? SLP offers chrome-plated 17-inch aluminum alloy wheels with huge Michelin performance tires engineered for the GTX Ram Air package. And there are a few other SLP items, such as a $799 ``spoiler style'' sunroof.

``The SLP equipment doesn't cause a Grand Prix to violate emissions laws,'' said SLP spokesman Reginald Harris. ``The first wave of GTX Ram Air buyers mostly are professionals with higher income and education levels than traditional buyers of mid-size cars. They want an alternative to cars such as the $50,500 BMW 540i and $50,600 Mercedes E430.''

So how does the GTX Ram Air perform? I drove one that had the supercharged engine, and it provided neck-snapping acceleration off the line and at highway speeds. The 260-horsepower 3.8 V-6 loafed at 1,800 r.p.m. at 65 m.p.h., and the larger tires allow better handling and braking.

The wheels, badging and four exhaust tips give the GTX Ram Air a nice custom appearance that turns heads, but the tires allow more road imperfections to be felt and more road noise to be heard. They also cause the quick power steering to feel somewhat dead.

There is nothing SLP can do about the Grand Prix's springy brake pedal, but the exhaust has a sportier sound.

The GTX Ram Air is plenty fast and distinctive, besides being less costly to buy and maintain than a high-performance foreign sedan. Those interested in the car can call the SLP customer assistance center at (800) 533-5673.