Larger in almost every dimension, the new Mercedez GLS is the first major redesign of Mercedes-Benz’s successful range-topping SUV since its launch as the 2007 GL. Available with either a 362-hp turbo 3.0-liter inline-six (GLS450) or a new 483-hp twin-turbo 4.0-liter V-8 (GLS580), both with 48-volt electrical architecture and electric assist. The overhaul ups the GLS’s luxury game substantially, including available five-zone climate control, a second-row bucket seat option, and an S-class-like executive rear-seat package.