Recipe for muscle car glory: Take one run-of-the-mill car, add a powerful V8 engine and give it a cool-sounding three-letter moniker, like GTO. That formula created the world's first muscle car four decades ago, and now it has been applied to the 2005 Pontiac Grand Prix GXP.
Pontiac's engineers have stuffed an all-aluminum V8 engine into the Grand Prix, fortified its suspension, added bigger brakes, 18-inch wheels and restyled front and rear fascias.
It's not only the first eight-cylinder Grand Prix in years, it's also the most expensive GP ever. Base price is a heady $29,335, and our heavily optioned test car stickered for $32,600, which is about the same as an Infiniti G35 and a Dodge Charger RT.
Muscle Car Hardware
The GXP's 5.3-liter pushrod small-block V8 is very similar to the engine used in Chevy's Silverado pickup, but Pontiac replaced the iron block with a lighter aluminum unit for this and other front-wheel-drive applications. Other changes include high-flow cylinder heads, a higher compression ratio and cylinder deactivation technology for improved fuel economy.
Output is 303 horsepower at 5,600 rpm, and 323 pound-feet of torque at 4,400 rpm, all of which is funneled into a four-speed automatic transmission controlled with Pontiac's TAPshift paddle shifters.
Underneath, the GXP's stiffer springs reduce ride height by 9mm, and Bilstein struts tighten up the suspension. A larger 17.2mm rear sway bar was added to reduce body roll, and forged aluminum five-spoke wheels with Bridgestone Potenza tires are also part of the package.
Oddly enough, the GXP's wheels measure 18-by-8 inches in front and 18-by-7 inches in back and the 255/45R18 front tires are fatter than the 225/50R18 rears. Usually it's the other way around, and the combo simply looks strange. When we asked Pontiac why all four corners didn't get the 8-inch wheel, we were told a computer simulation determined this is the optimal setup for handling and acceleration.
We think Pontiac's engineers should leave their computer terminals for the test track every once in a while. Although the GXP's upgraded suspension and oddball wheel and tire combination rides well enough, it doesn't supply the off-the-line traction or cornering grip we expected.
Torque Steer City
Stuffing a V8 into a front-wheel-drive platform is a surefire recipe for torque steer, and Pontiac's engineers have cooked up plenty of it. Hammering the pedal at any speed causes the car to dart around like there's a drunk behind the wheel. And laying into it from a dead stop, even with GXP's traction control turned on, results in immediate wheelspin, which slows the Grand Prix's acceleration.
Pontiac claims the GXP will run zero to 60 mph in 5.9 seconds, but our best run was a tire-smoking 6.7 seconds. We've yet to wring out a Hemi-powered Charger RT, which is the GXP's closest competitor, but our long-term Magnum RT, which weighs 500 pounds more than the Pontiac and 150 pounds more than a Hemi Charger, hits 60 mph in 6.8 seconds.
Once the GXP hooks up, however, it does leave the larger Magnum in the dust, running the quarter-mile in 14.6 seconds at 95.4 mph. And it sounds great doing it, with just the right amount of rumble.
The torque steer also limits the GXP's appeal on a mountain road, especially when exiting slow corners. Numb and disconnected steering, a nose-heavy feel and a nasty delay before the transmission actually reacts to the driver's "taps" also sap the GXP of fun-to-drive points. Even the design of the TAPshift "paddles" mounted on either side of the steering wheel should be better. As it is, they're counterintuitive. Pushing forward shifts up, while pulling back downshifts.
Its braking performance is good but not great. The Pontiac's cross-drilled rotors (12.7 inches front, 12 inches rear) are nice to look at, but the calipers are only two-piston in front and single-piston out back. The results are good resistance to overheating, a 60-0-mph performance of 124.1 feet and fair pedal feel.
High Content, Low Style
The overall look of the GXP isn't much different than the standard Grand Prix save for the big shiny wheels and drilled brakes. Other extras include an aggressive front fascia with lower air inlets, restyled rear fascia with dual exhaust cutouts, a rear deck spoiler and air ducts in the front fenders.
Inside, the Grand Prix's interior is on the tight side for such a large car, but the GXP gets brushed aluminum interior accents and an engine-turned metal gauge cluster that hearkens back to the early days of Pontiac performance. Fit and finish, however, is lackluster, with large expanses of hard plastic and ill-fitting panels that look more rental car than muscle car.
Pontiac did manage to get the front seats to feel just right and the feature content is impressive. Stability control, OnStar, steering wheel radio controls, a 60/40 split-folding rear seat, a head-up display, keyless entry and a CD player are standard. Our test car added leather seating with suede inserts, a power sunroof, XM Satellite Radio, a special paint color called Blue-Green Crystal, automatic dual-zone climate control and a remote vehicle starter.
Final Thoughts
Ten years ago we might have looked at a 300-hp V8 Pontiac sedan more favorably, but today there are over a dozen cars competing in the $30,000-$35,000 sport sedan segment, and the GXP just can't compete with its rear-wheel-drive rivals like the Charger.
The V8 power is nice, but with its crude interior, vague steering and massive torque steer the 2005 Pontiac Grand Prix GXP is never much fun.
Pontiac's engineers have stuffed an all-aluminum V8 engine into the Grand Prix, fortified its suspension, added bigger brakes, 18-inch wheels and restyled front and rear fascias.
It's not only the first eight-cylinder Grand Prix in years, it's also the most expensive GP ever. Base price is a heady $29,335, and our heavily optioned test car stickered for $32,600, which is about the same as an Infiniti G35 and a Dodge Charger RT.
Muscle Car Hardware
The GXP's 5.3-liter pushrod small-block V8 is very similar to the engine used in Chevy's Silverado pickup, but Pontiac replaced the iron block with a lighter aluminum unit for this and other front-wheel-drive applications. Other changes include high-flow cylinder heads, a higher compression ratio and cylinder deactivation technology for improved fuel economy.
Output is 303 horsepower at 5,600 rpm, and 323 pound-feet of torque at 4,400 rpm, all of which is funneled into a four-speed automatic transmission controlled with Pontiac's TAPshift paddle shifters.
Underneath, the GXP's stiffer springs reduce ride height by 9mm, and Bilstein struts tighten up the suspension. A larger 17.2mm rear sway bar was added to reduce body roll, and forged aluminum five-spoke wheels with Bridgestone Potenza tires are also part of the package.
Oddly enough, the GXP's wheels measure 18-by-8 inches in front and 18-by-7 inches in back and the 255/45R18 front tires are fatter than the 225/50R18 rears. Usually it's the other way around, and the combo simply looks strange. When we asked Pontiac why all four corners didn't get the 8-inch wheel, we were told a computer simulation determined this is the optimal setup for handling and acceleration.
We think Pontiac's engineers should leave their computer terminals for the test track every once in a while. Although the GXP's upgraded suspension and oddball wheel and tire combination rides well enough, it doesn't supply the off-the-line traction or cornering grip we expected.
Torque Steer City
Stuffing a V8 into a front-wheel-drive platform is a surefire recipe for torque steer, and Pontiac's engineers have cooked up plenty of it. Hammering the pedal at any speed causes the car to dart around like there's a drunk behind the wheel. And laying into it from a dead stop, even with GXP's traction control turned on, results in immediate wheelspin, which slows the Grand Prix's acceleration.
Pontiac claims the GXP will run zero to 60 mph in 5.9 seconds, but our best run was a tire-smoking 6.7 seconds. We've yet to wring out a Hemi-powered Charger RT, which is the GXP's closest competitor, but our long-term Magnum RT, which weighs 500 pounds more than the Pontiac and 150 pounds more than a Hemi Charger, hits 60 mph in 6.8 seconds.
Once the GXP hooks up, however, it does leave the larger Magnum in the dust, running the quarter-mile in 14.6 seconds at 95.4 mph. And it sounds great doing it, with just the right amount of rumble.
The torque steer also limits the GXP's appeal on a mountain road, especially when exiting slow corners. Numb and disconnected steering, a nose-heavy feel and a nasty delay before the transmission actually reacts to the driver's "taps" also sap the GXP of fun-to-drive points. Even the design of the TAPshift "paddles" mounted on either side of the steering wheel should be better. As it is, they're counterintuitive. Pushing forward shifts up, while pulling back downshifts.
Its braking performance is good but not great. The Pontiac's cross-drilled rotors (12.7 inches front, 12 inches rear) are nice to look at, but the calipers are only two-piston in front and single-piston out back. The results are good resistance to overheating, a 60-0-mph performance of 124.1 feet and fair pedal feel.
High Content, Low Style
The overall look of the GXP isn't much different than the standard Grand Prix save for the big shiny wheels and drilled brakes. Other extras include an aggressive front fascia with lower air inlets, restyled rear fascia with dual exhaust cutouts, a rear deck spoiler and air ducts in the front fenders.
Inside, the Grand Prix's interior is on the tight side for such a large car, but the GXP gets brushed aluminum interior accents and an engine-turned metal gauge cluster that hearkens back to the early days of Pontiac performance. Fit and finish, however, is lackluster, with large expanses of hard plastic and ill-fitting panels that look more rental car than muscle car.
Pontiac did manage to get the front seats to feel just right and the feature content is impressive. Stability control, OnStar, steering wheel radio controls, a 60/40 split-folding rear seat, a head-up display, keyless entry and a CD player are standard. Our test car added leather seating with suede inserts, a power sunroof, XM Satellite Radio, a special paint color called Blue-Green Crystal, automatic dual-zone climate control and a remote vehicle starter.
Final Thoughts
Ten years ago we might have looked at a 300-hp V8 Pontiac sedan more favorably, but today there are over a dozen cars competing in the $30,000-$35,000 sport sedan segment, and the GXP just can't compete with its rear-wheel-drive rivals like the Charger.
The V8 power is nice, but with its crude interior, vague steering and massive torque steer the 2005 Pontiac Grand Prix GXP is never much fun.
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