The Mercedes Benz GLS is offered in three basic flavors. The GLS450 uses a twin-turbocharged 3.0L V6 that makes 362 hp. The GLS550 has a 4.7L twin-turbo V8 and produces 449 hp and 516 lb-ft of torque. At the top of the GLS hierarchy is the performance-oriented AMG GLS63. Its hand-built 5.5L V8 makes 577 hp and 561 lb-ft of torque. All GLS models use an advanced 9-speed automatic transmission, which sends power to all four wheels. Being a full-sized luxury SUV means that GLS comes very well-equipped, even before the options sheet comes into play. Standard interior features include MB-Tex seating surfaces, a power driver's seat with a memory function, heated front seats, shift paddles, an 8-inch high-resolution touch-screen monitor, eucalyptus wood interior trim, Bluetooth connectivity, a five-year subscription to Mercedes-Benz's mbrace Connect system, power folding rear seats, power folding side mirrors, a power tilt and telescoping steering column, a power liftgate and a power sunroof. Other standard features on the GLS include AIRMATIC suspension, 19-inch wheels, an active brake assist system, crosswind assist, a rearview camera and 11 airbags. Of course, it wouldn't be a Mercedes-Benz if the option list wasn't long enough to spec the vehicle precisely to the buyer's desires. A Grand Edition for GLS 450 and GLS 550 models offers Porcelain/Espresso Brown Napa leather with natural-grain Linden wood trim, unique wheels, and special badging. A parking assist package adds a 360-degree camera system as well as a system to park the vehicle with minimal input from the driver. A Premium 1 package adds multicolor interior lighting, a blind spot detection system, keyless entry and start, a memory system for the front passenger, SiriusXM satellite radio and better smartphone integration with Apple CarPlay. Stand-alone options include a heated steering wheel, a Bang & Olufsen sound system, an air purification system, a rear seat entertainment system as well as a trailer hitch. All GLS models can tow up to 7500 pounds when properly equipped.