The ideal touring car makes itself transparent to the driver. The driving experience is noticeable, not the vehicle providing that experience. Anyone test-driving such a car has to consciously force their attention through to the vehicle instead of simply enjoying the ease of motion, the willingness of the engine, the responsiveness of the brakes. The driver has to look for those aspects of the car that its designers have worked to make seamless. We paid attention to those details and allowed ourselves to enjoy the experience.

To maintain peak performance athletes might clamp an oxygen mask to their face. That's what an engine is doing with a turbo or supercharger: forcing more oxygen inside. While a turbo comes into play after the engine is spooled up a bit, a supercharger is there from the get-go. The 3.8-liter V6 in the Grand Prix is normally aspirated in the base model but supercharged in the GT. The supercharger lowers gas mileage slightly, but adds 60 horsepower, boosting output to 260 hp. The additional thrust this provides reduces by some two seconds in the time it takes to reach 60 mph from a standstill. We're talking 0-60 in just 6.5 seconds, which is very quick indeed. The acceleration performance of the GT is comforting when merging or passing in tight situations on two-lane roads.

Yet gas mileage is still respectable: The base Grand Prix gets an EPA-estimated 20/30 mpg City/Highway, and the GT gets 19/28 mpg.

Another way to increase performance can be summed up in the old adage: there's no substitute for cubic inches. The GXP has 325 cubes, which brings horsepower to 303 and torque to a stump-pulling 323 pound-feet. The V8 cuts the 0-60 mph time to 5.6 seconds, which is darn quick, especially for a front-drive sedan. Gas mileage suffers only slightly, with EPA numbers of 18 mpg city and 27 highway.

Usually when even 200 horsepower is put through the front wheels of a front-wheel-drive car a phenomenon known as torque steer ensues. Torque steer is felt as a disconcerting tug at the steering wheel under rapid acceleration. It's like the front wheels are in a race with each other. So it's impressive that there's so little torque steer in the Grand Prix, even when putting 303 ponies to the pavement. Pull away smoothly with the right foot down hard and the Grand Prix is as stable as an Acura. Keep your foot to the floor, and the V8 keeps pulling. The front-wheel drive makes you feel like you're being pulled instead of propelled forward like you would in a rear-drive car. It's fun but we think V8s are best balanced with rear-wheel drive. The V6s are better balanced to the front-drive layout of the Grand Prix.

The four-speed automatic transmission shifts in smooth increments, but downshifts can deliver a notable kick when stomping the throttle in the GXP. An electronic traction control system (ETC) has a speed-based response mechanism meaning that the car is tractable around town without goosey overreaction, but answers the call for power instantly at highway speeds. It should be noted, however, that the Grand Prix is equipped with a four-speed automatic while the latest designs use six-speed automatics.

The GXP has steering-wheel-mounted buttons to give the driver the option of semi-manual shifting, called TAPshift (Touch Activated Power). Press down on the button to select a lower gear, up on for a higher gear; a button is on each side of the steering wheel. Quick to respond, TAPshift offers more control over shifting for driving entertainment or to reduce shifting in hilly terrain. TAPshift is also programmed to hold gears longer than other such systems, improving the GXP's responsiveness when driving hard.

In terms of ride quality, the base Grand Prix model offers the most traditional ride, the GT and GXP are tighter for secure cornering yet retain enough compliance to provide a relatively soft ride.

The GXP is a blast through long, sweeping corners, but a little big and cumbersome for tight switchbacks. The GXP suspension system makes it capable of 0.82g of lateral acceleration force, which is fine for a front-drive sedan, but not comparable to a Corvette. Considering the amount of power put through the front wheels and the size of the car, the GXP handles well, but doesn't have the poise of the better European sedans through turns. (We said pretty much the same thing about the Acura TL.)

As for braking, the GXP four-wheel vented discs pull it to a stop from 60 mph in 120 feet. That is commendable and satisfying, but the base and GT models aren't as capable.