The Mercedes-AMG GLS63 returns to Merc’s product offering for the 2021 model year after a brief hiatus and comes well-prepared for its battle with other mega-horsepower mega-SUVs. Its 4.0-liter twin-turbo V8 produces 603 hp and 627 lb-ft of torque, while an EQ Boost starter-generator adds another 21 horses and 184 lb-ft of twist. A nine-speed automatic transmission controls shifts while a 4MATIC+ all-wheel-drive system aids with traction and helps get the hefty beast from 0-60 mph in just 4.1 seconds. Top speed is limited to 174 mph. Inside, the leather seats feature heating, ventilation, and massage functions in the first row as standard, although this can be added to the second row of seats too. Other standard equipment includes a pair of 12.3-inch digital displays and a Burmester sound system. Tri-zone automatic climate control is included too, as are soft-close doors.