The 2008 Pontiac G8 lineup offers two models: G8 and G8 GT. A sport package is available for both models and adds features such as specific wheels (including 19-inch aluminum wheels and performance tires on GT), a rear wing spoiler, leather shift knob, leather-wrapped steering wheel and alloy pedals.

Distinctive elements include hood scoops and front fender vents, as well as projector-beam headlamps housed in crystal-clear lenses. At the rear, jewel-like taillamps are mounted in housings and feature bright detail work surrounding the red lighting elements. G8 models have red taillamp lenses and twin chrome exhaust outlets, while G8 GT models feature clear taillamp lenses and quad chrome exhaust tips. All models have an antenna mounted at the rear of the roof.

The base G8 model uses a 3.6-liter V-6 with 261 horsepower, paired with a five-speed automatic transmission with manual shift mode.

The G8 GT is powered by a 6.0-liter V-8 rated at 362 horsepower and 391 lb-ft of torque. The engine features the fuel-saving Active Fuel Management system, which enhances fuel economy by alternating between eight- and four-cylinder power. A six-speed automatic transmission with manual shift mode is standard. A six-speed manual is also available.