About This GMC Sierra 2500

The 2020 GMC Sierra 2500HD AT4 is a heavy-duty pickup that combines off-road capability, advanced trailering technology, and premium interior comfort. Finished in Onyx Black over a Jet Black/Kalahari interior, this redesigned generation brought significant updates for 2020, including enhanced towing features and the versatile MultiPro tailgate.
Power comes from a 6.6-liter Duramax turbodiesel V8 producing 445 horsepower and 910 lb-ft of torque. It's paired with an Allison 10-speed automatic transmission and a 2-speed transfer case with an automatic mode, sending power to all four wheels. This drivetrain is engineered for serious hauling and towing while maintaining smooth power delivery under load.
The AT4 trim adds distinctive styling and capability enhancements. Exterior highlights include 20-inch machined aluminum black wheels, LED headlights, LED roof-marker lamps, towing mirrors, black assist steps, a receiver hitch, gooseneck hitch provisions, a spray-in bed liner, bed-mounted power outlets, and the MultiPro tailgate that can function as a step, load stop, or work surface.
Inside, the cabin blends durability with comfort. Leather upholstery covers heated and ventilated power-adjustable front seats with driver memory, while rear passengers benefit from heated seats. A heated steering wheel and dual-zone automatic climate control enhance everyday usability. Technology features include an 8-inch GMC infotainment system with Apple CarPlay and Android Auto, Bluetooth connectivity, wireless charging, a Bose premium sound system, front and rear park assist, lane change alert, rear cross-traffic alert, and multiple cabin power outlets including household-style, USB, and USB-C connections. A sunroof further brightens the interior.
With its high-torque diesel engine, off-road-ready AT4 configuration, and well-equipped interior, this 2020 Sierra 2500HD AT4 delivers a strong balance of work capability, trail confidence, and daily comfort.