Corvette Power, Mad Max Mojo

About 19 months ago, we sent operatives with a briefcase bristling with test equipment to Australia. The mission: Get an early peek at the 2008 Pontiac G8 GT by test-driving its stablemate, the then-new 2007 Holden Commodore SS.

The residual jet lag was magically wiped away by the Commodore SS’s thrilling combination of rear-wheel drive, independent rear suspension, a six-speed manual transmission and a 6.0-liter V8. Or maybe it was the Mad Max flashbacks and the Vegemite.

Yet even though we loved the 2008 Pontiac G8 when it hit the streets in the U.S. eight months ago, we knew that the Aussie mojo from the Commodore SS hadn’t made the trip from the Land of Oz.

Turns out that Pontiac was holding a few aces up its sleeve, and now the 2009 Pontiac G8 GXP puts them all on the table.

The Most Powerful Production Pontiac…Ever?

Ace No. 1 is the 2009 Pontiac GXP’s LS3 V8, the base engine found under the hood of the 2008 Corvette. Displacing 6.2 liters (376 cubic inches), the G8 GXP version makes 415 horsepower and 415 pound-feet of torque, some 54 hp and 30 lb-ft more than the G8 GT’s V8 engine.

The 2009 Pontiac G8 GXP is the most powerful production Pontiac built to date. Really.

You could argue that the 1970 Pontiac Trans Am could be equipped with a 400-cubic-inch Ram Air V, which was rated at 500 hp. But this special-order engine was a dealer-installed item, and it would never withstand a grocery run on 91 octane gasoline or live long enough to meet a 100,000-mile powertrain warranty, and hooking one up for a 2008 smog test would be, um, futile.

Moreover, the 2009 Pontiac G8 GXP’s 415-hp rating is certified as an SAE net output, which means it was produced under tightly controlled test procedures that include the presence of an independent observer.

Twisting the key brings this engine to life with a burbling idle that the 6.0-liter V8 of our 2008 Pontiac G8 GT long-term test car can’t match. There’s plenty of life under the throttle pedal, as the GXP responds with the kind of healthy shove to the backside you’d get if someone put a sign on the back of your jacket that said, “Kick me.”

The exhaust note that comes from the GXP’s low-restriction exhaust system contains just enough of that high-school rock-and-roll soundtrack to make us want to stand on the power pedal whenever possible, yet it’s not offensive enough that the old guy down the street will shake his cane at us. And did we mention the off-throttle burble?

But there is a dark side. The GXP’s fuel consumption figures are expected to settle near those of the base Corvette, which are 14 mpg city and 20 mpg highway. Plus the Corvette gets slapped with a $1,700 gas-guzzler tax, so it’s likely the GXP will, too.

Source: 2009 Pontiac G8 GXP Follow-Up Test