The GLS-Class may be a massive, luxury SUV, but the amount of performance the vehicle provides is impressive. While the base twin-turbo 3.0-liter V6’s output of 362 hp and 369 pound-feet of torque is nothing to sneer at, the V8 engines are especially noteworthy. The first step above the V6 is a twin-turbocharged 4.7-liter V8 that produces 449 hp and 516 lb-ft of torque. The real jewel of the family, though, is the AMG GLS 63 that features a handcrafted-5.5-liter twin-turbo V8. The sledgehammer of an engine produces 577 hp and 561 lb-ft of torque. Despite the SUV’s size, the AMG variant can get to 60 mph in 4.5 seconds, besting some sports cars on the market.
While the GLS-Class engines are smooth operators, the way the SUV handles and hides its stature is stunning. A standard air suspension system means that you’re rarely feeling bumps, while the all-wheel-drive system can not only get you through inclement weather, but over some rough terrain, too. Around corners, the GLS-Class’ ability to feel like a smaller vehicle is also remarkable, as the available Active Curve System works to keep body lean to a minimum.
The nine-speed automatic transmission on lower trims can feel busy at times, hunting for the right gear, especially when driving on the highway. Another downside, and this is the major one for the GLS-Class, is terrible fuel economy. The best the GLS manages to get is an EPA-estimated 16 miles per gallon city, 22 mpg highway, and 18 combined, which is bad, even for the segment.