The G8 is available in base trim and the sportier GT. The base trim employs a 256-hp 3.6-liter V6 engine paired with a five-speed automatic transmission featuring manual shift control, while the GT is powered by a 361-hp 6.0-liter V8 engine bolted to a six-speed automatic, also with manual shift control. Standard safety features include six airbags, four-wheel disc anti-lock brakes, traction control, stability control, OnStar and tire pressure monitoring. Standard equipment includes sport suspension, 18-inch alloy wheels, and satellite radio. The GT features automatic dual-zone climate control, premium 6-disc Blaupunkt sound system, performance tires and a limited slip differential. Optional features such as power sunroof and heated seats are available on both trims, and 19-inch alloy wheels are available on the GT. For 2009, XM satellite radio becomes standard equipment on the both trims. The G8 was all-new for the 2008 model year.