The 2021 GMC Yukon AT4 is an off-road-focused trim of the redesigned full-size SUV, featuring standard 4WD, skid plates, tow hooks, and an available Air Ride Adaptive Suspension for improved ground clearance and capability. It comes with a 5.3L V8 engine (355 hp) and a 10-speed automatic transmission, offering a blend of ruggedness with luxury features like standard leather seats, heated/ventilated front seats, and an available Head-Up Display with an off-road inclinometer. Key upgrades include an independent rear suspension for better ride and handling, and advanced camera systems for off-road visibility.