From Pontiac press: The G8 GXP takes the G8s responsive driving experience, refined passenger environment and aggressive good looks to a new level. It also delivers an enjoyable driving experience, thanks to a 6.2L V-8 that produces in excess of 400 horsepower.
More than just raw power, the GXP delivers the sophisticated yet exciting driving experience that enthusiasts expect in a car costing far more than the GXP, said Jim Bunnell, Buick-Pontiac-GMC general manager
The heart of the G8 GXP is the 6.2L LS3 small-block V-8, currently rated at 402 horsepower (300 kW)* and 402 lb.-ft. of torque (546 Nm)* pending final SAE certification. This engine is the newest member of GMs small-block V-8 family. It features a revised, larger-bore cylinder block, high-flow, L92-style cylinder heads; larger-diameter pistons; unique camshaft and camshaft timing; revised valvetrain with offset intake rocker arms; high-flow intake manifold; and high-flow fuel injectors.
The LS3 engine has an aluminum cylinder block with cast-in-place iron cylinder liners. Larger bores help create a 376-cubic-inch displacement. The block casting also features revisions and machining in the bulkheads to enhance its strength and improve bay-to-bay breathing. New pistons were designed for high-rpm performance.
New, high-flow cylinder heads aid engine breathing and are based on the large port and valve design found on the LS7 engine and other GM L76 engines. The larger-capacity, straighter intake port-design optimizes intake flow to the combustion chamber, an effect augmented by large valves, measuring 2.16 inches (55.0 mm) on the intake side and 1.59 inches (40.4 mm) on the exhaust side.
Pending final testing, the G8 GXP is expected to deliver 0-to-60 mph performance of about 4.7 seconds, and a quarter-mile time of 13.0 seconds at 108 mph.
The G8 GXP rides on the G8s 114.8-inch (2915 mm) wheelbase with wide front ( 62.7 inches / 1,592 mm) and rear ( 63.3 inches / 1,608 mm) tracks. The four-wheel independent suspension is fully adjustable and is tuned for the highest performance in the G8 family. The GXPs ride and handling was developed and validated on racetracks and highways around the world, including the famed Nrburgring racing circuit. It rewards the driver with sharp, immediate responses, as well as a well-balanced road feel during spirited driving.