- Editor:
- New Car Test Drive
- Price As Tested:
- $34,090
“Well-engineered sports sedan with rear-wheel drive.”
From the driver's perspective, the Pontiac G8 has lots of strengths and no glaring weaknesses. From the passenger's perspective, it's quiet and comfortable. From the driver's seat, the G8 feels smaller than it is, and that's a compliment. We'd call the G8 a sports sedan, at least from the mid-line GT upward. Next to the Cadillac CTS, it's the best performance-oriented four-door General Motors has introduced in years.
The 3.6-liter V6 in the G8 is same engine as that used the Cadillac CTS. It has dual overhead cams with continuously variable valve timing, and delivers 256 horsepower and 248 pound-feet of torque at a low 2100 rpm. The acceleration is good, but the exhaust note is raspy and not very pleasing when you're hard on the throttle. On the freeway at steady light throttle, the V6 is quiet.
What we liked least about the G8 V6 was its five-speed automatic transmission. The combination simply lacks the range and overall responsiveness of the GT's V8 and six-speed automatic. We got some good miles in the base G8, over twisty roads suited for sporty driving, and in Sport mode the transmission kept kicking down multiple gears like crazy. All it really did was make the car feel rougher than it is in Cruise mode.
Further, the suspension on the base G8 doesn't have the same taut feel as that on the GT. The G8 V6 is designed for drivers who love the style but don't need lots of performance. The V6 model is less aggressive in every respect. It gets better fuel economy than the V8 and it runs on regular fuel. The G8 V8 models require premium to achieve full power.
Before the GXP came out, the mid-line G8 GT was one of best performers in the class and we found it to be an enjoyable car to drive.
We drove the GT on one of our favorite roads, from San Diego to Borrego Springs, California, with little traffic, good visibility and the desert in full bloom. We finished without a single gripe about the performance of the G8 GT in areas that matter most: engine, transmission, suspension, brakes. The GT's 6.0-liter cam-in-block engine makes 361 horsepower and 385 pound-feet of torque. The torque peaks at a fairly high 4400 rpm, but the engine doesn't feel peaky all. Overall, the GT feels trim.
Before introduction of the new G8 GXP, the GT already had more power than any production Pontiac in history (take that, you Firebird Trans-Am Ram Air big honkin' hood scoop muscle cars). Yet the GT is totally tame until you want to use that power. Then it will accelerate from 0 to 60 in 5.1 seconds and knock off the quarter-mile in 13.8, according to Pontiac. And with all the torque on tap, the engine just lopes through places and situations that require other sedans to take a harder swing.
The 6.0-liter V8 features GM's Active Fuel Management technology, which allows it to operate as a four-cylinder under light loads: When cruising at a steady 60 mph, for example. The switch between four- and eight-cylinder operation is usually imperceptible, and it edges the GT up to its EPA rating of a combined 20 mpg. That's impressive for 360 horsepower, and it was unthinkable just a few years ago. We averaged 16.2 miles per gallon in our test GT, with a little freeway mixed into hard two-lane running for a couple of hours.
Maybe the best thing about the G8 GT is its six-speed automatic transmission. Pontiac has joined the slim ranks of the savvy by making a tight-shifting automatic with manual control that's absolutely faithful to the driver's commands. It makes sport driving a pleasure in the GT.
There are three modes for Pontiac's Driver Shift Control transmission: Cruise, Sport and Manual. Cruise is fully automatic; Sport is automatic with more aggressive shift points, and Manual is, totally, manual. In Manual, the transmission will short shift, or upshift under hard throttle below redline. Sometimes that's a useful and smooth technique, and far too many manually shifted automatic transmissions are programmed to disallow it. The thinking (by some engineer, somewhere) seems to be that hard throttle means full speed means full revs. No, not necessarily. The G8 GT transmission employs rev matching for smoother downshifting, and the revs are just right. There are rational limits to the manual control, however: It won't let you downshift if the lower gear would cause the engine to over-rev, but it will allow you to reach redline and stay there. It won't upshift for you, in manual mode, unless you move the shift lever yourself. The G8 doesn't offer the steering-wheel mounted paddle shifters often used with transmissions of this type, but we didn't miss them. And for fully automatic shifting, the Sport mode is actually useful. Some aren't, because they just make the power delivery jerky. Cruise mode is true, too, for smooth cruising. You don't feel each downshift at every red light and stop sign. This transmission understands gliding, and that may be what we like best. For all its sporting characteristics and effectiveness when shifted manually, the G8 GT's transmission can be as smooth and comfortable as any luxury car's when the driver is just plodding along. The GT transmission is the same one used in GXP, and it's so effective that we might take it over the optional manual, even if we didn't drive in traffic.
The GT's suspension is firm enough, too, and its handling is tight, but the ride is never uncomfortable. This as much as anything distinguishes it from Pontiac's previous efforts to build a sports sedan, and it's a function of good development work. The steering rack is mounted forward of the front axle, which Pontiac engineers say improves response. The engine sits low and rearward in the chassis cradle, and little tricks like a rear-mounted battery helped balance the car to a 50:50 weight distribution front-rear. The G8's body is built with 80 percent high-strength steel, which allows the suspension to do its job well and helps control interior vibration.
We found the handling confident, precise and sharp. The electronic stability control is tuned like that on some of the best European sport sedans. During our hard drive to Borrego Springs, the stability control activated maybe three times, and at just at the right times, as when the rear wheels began bouncing slightly from the road surface. In that situation, some systems will cut the throttle so much the car falls on its nose and makes you curse. Not so with the G8 GT, which cuts the throttle just for a split second and then lets you continue to drive the car.
We found the ride quality of the GT excellent. Compared to the Mercedes C63 AMG, a $50,800 challenger to the BMW M3 we tested on Arizona back roads the day before we drove the Pontiac, the G8 GT's ride is more pleasing, lacking all harshness. Yet despite the general comfort we never hit a spot where the G8 GT felt in over its head, as in being too soft in a hard corner. And we tried to find that spot.
The GXP is the hottest model and can accelerate from 0-60 mph in 4.7 seconds, says Pontiac, with a quarter-mile run of 13.0 seconds at 108 mph. That makes the GXP one of the quickest sedans in its price range. The GXP is powered by GM's LS3 V8, which also serves as the base engine in the Chevy Corvette. While the GT comes with a 6.0-liter engine, the GXP gets a 6.2-liter V8. The GXP is rated at 402 horsepower, 402 pound-feet of torque. The GXP also adds more performance goodies, including a standard limited-slip differential and 19-inch summer performance tires, and it's available with a six-speed manual transmission. Fuel economy is an EPA-estimated City/Highway 13/20 mpg, landing the GXP a federal Gas Guzzler Tax of $1,700, which you'll need to add to the price.
We like manual transmissions and the Tremec six-speed manual in the GXP shifts nicely. We grew tired of it around town, however. The relatively heavy clutch pedal and strong engine torque conspired to produce a jerky ride around town; it demanded attention and skill to drive smoothly and we weren't always in the mood for this. For around town use, we'd prefer the automatic.
Pontiac developed the GXP suspension on Germany's famous Nurburgring open-road race course. It's firmer than the GT suspension but we didn't find it harsh around town.
We used the brakes on the GT good and hard, and never reached a point were they got hot enough to start losing stopping power. The vented rotors are big, and they meet the high performance standard set by the engine, transmission and suspension.
The GXP offers larger rotors still, with lightweight aluminum calipers provided by Brembo. The advantages here are resistance to fade after repeated hard usage and more powerful braking to take advantage of the upgraded tires.