The 2008 Pontiac G6 offers a variety of driving experiences depending upon which engine it is outfitted with, but overall performance isn't exceptional—though GXP versions have smoother power and handling.
The 2008 Pontiac G6 can be equipped with one of three engine choices, based on the trim level. Cars.com reviewers say that "the base sedan holds a 164-horsepower, 2.4-liter four-cylinder" engine, as does the Value Leader, "while GXP editions feature a 252-hp, 3.6-liter V-6." In between the two lies a "219-hp, 3.5-liter V-6" in the Pontiac G6 GT models, according to Cars.com. Edmunds notes that "the fuel-efficient 3.5-liter V6 delivers plenty of low-end torque for quick acceleration and easy passing," and the "GXP offers the most performance and sophistication for enthusiasts." None of those reviewers had a chance to drive a four-cylinder, but in previous test drives, TheCarConnection.com’s editors felt the base four-cylinder engine has just adequate acceleration and is quite coarse when pushed, though it delivers good fuel economy (30 mpg highway).
In order to simplify both manufacturing and purchasing, Pontiac offers just one transmission for each engine type on the 2008 Pontiac G6. Kelley Blue Book describes this transmission as a "four-speed automatic" with the 2.4-liter and 3.5-liter engines, while the Pontiac G6 GXP pairs a "six-speed automatic transmission" with its V-6. The four-speed is panned in reviews, with Car and Driver claiming that its "gearing gaps are canyonlike," though it "doesn't shy away from revving its partner to successive 5800-rpm shifts" if you "mash the throttle." Kelley Blue Book describes the performance of the four-speed auto as "decidedly underwhelming." On the other hand, the six-speed auto receives much more positive reviews, with Kelley Blue Book saying that the Pontiac "G6 feels its most athletic" with this transmission. ConsumerGuide adds that the transmission will "downshift readily for impressive passing response."
For those not interested in the power that the V-6 engines offer, the four-cylinder provides a thrifty alternative. The EPA estimates that the 2.4-liter engine on the lower-trim Pontiac G6s will get 22 mpg city and 30 mpg on the highway. This compares with EPA estimates of 18/29 mpg for the 3.5-liter engine and 17/26 mpg on the six-speed-equipped 3.6-liter. Edmunds reviewers feel that these numbers are "mostly on par for the midsize segment."
One of the most common complaints in reviews read by TheCarConnection.com arises when talking about handling in this 2008 Pontiac. ConsumerGuide reviewers mention that the steering "feels numb on the whole," though Edmunds adds that "the hydraulic power steering included on GT and GXP models (and optional on the standard G6) is much more communicative." Cars.com writes that overall "handling is on the ordinary side," and Car and Driver says that the 2008 Pontiac G6 feels "more floaty than sporty." In terms of ride quality, the Pontiac G6 offers a more positive experience, with Car and Driver testers finding that the "forgiving suspension" delivers a "supple, comfortable ride, even over the ragged, uneven roads outside Ann Arbor's city limits." Finally, ConsumerGuide calls the braking on the 2008 Pontiac G6 "slightly dull."