The 2012 Mercedes-Benz ML 63 AMG hits the road this spring with more power and better fuel efficiency -- by a whopping 28% over its predecessor. The high-performance SUV gets power from an AMG 5.5L twin-turbo V8 engine with peak horsepower of 525 and peak torque of 516 lb-ft, 15 more horses and 50 more lb-ft than before. An optional AMG Performance package boosts output to 557 hp and max torque to 560 lb-ft.