The 2013 Mercedes-Benz GL-Class SUV upholds the Mercedes-Benz traditions yet it's every bit a workhorse as it is spacious and serene on the inside. The power behind the 2013 Mercedes-Benz GL450 4MATIC® is from the 4.6-liter bi-turbo V8 engine that generates 362 hp between 5,000 -- 6,000 rpm. For greater power, look to the 2013 GL550 4MATIC® SUV that produces 429 hp at 5,250 RPM and wears robust 21-inch wheels.