The 2010 Mercedes-Benz G-wagon is powered by a 5.5-liter V8 that produces 382 horsepower and 391 pound-feet of torque. ... The G55 AMG gets a supercharged 5.4-liter V8 that pumps out 500 hp and 516 lb-ft of torque. It gets the same four-wheel-drive system, but has a five-speed automatic.