The biggest Mercedes-Benz SUV is the GL-Class, a direct competitor of the Cadillac Escalades and Range Rovers of the world. Its elegant passenger compartment seats up to seven very comfortably. With a BlueTEC diesel engine, this mastodon can even be fuel efficient, using just 8 litres per 100 km on the highway! Even though this is the most suitable engine for the vehicle, AMG is still offering a GL63 for power enthusiasts.