The 2008 G6 is a 2- or 4-door, up to 5-passenger convertible, sports car, family sedan, or sports sedan, available in 7 trims, ranging from the 1SV Sedan to the GT Convertible.

Upon introduction, the 1SV Sedan is equipped with a standard 2.4-liter, I4, 169-horsepower engine that achieves 23-mpg in the city and 33-mpg on the highway. The GT Convertible is equipped with a standard 3.5-liter, V6, 217-horsepower engine that achieves 20-mpg in the city and 28-mpg on the highway. A 4-speed automatic transmission with overdrive is standard on both trims.

The 2008 G6 is a carryover from 2007.