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Take your adventures off the pavement with the 2026 GMC Sierra HD AT4 or AT4X. Both of these trims are designed to be tough enough to handle rugged terrain. Modern amenities keep you comfortable and informed no matter where the road takes you.
Power for the 2026 GMC Sierra HD AT4 and AT4X comes from a Duramax 6.6L Turbo-Diesel V8 engine, which delivers 470 horsepower and 975 lb.-foot of torque. This engine is paired with a ten-speed automatic transmission while an exhaust brake keeps you in control with a heavy load. Take on bigger challenges with the AT4X, which has up to 11.6 inches of ground clearance and an approach angle of 31.6 degrees and departure angle of 25.7 degrees.
The 2026 GMC Sierra HD AT4 and AT4X are designed for a rugged lifestyle, beginning with skid plates and stamped-steel bumpers. Twenty-inch gloss black aluminum wheels are sure to garner attention while BFGoodrich off-road tires enhance the capability of the truck. Sink down into 16-way power heated and ventilated front seats with massage to relax tired muscles. Sit higher off the road with an optional 1.5-inch suspension lift.
Always be connected in the 2026 GMC Sierra HD AT4 and AT4X with a 13.4-inch diagonal premium GMC Infotainment System, which you can connect to your phone via wireless Android Auto or Apple CarPlay. You can see your apps and access information with voice activation. A 12.3-inch diagonal color Driver Information Center provides vehicle data as you travel.
One of the main updates for the 2026 GMC Sierra HD AT4 and AT4X is the addition of an electric model for the AT4. The AEV has underbody skid plates and a suspension kit. Underbody protection was added to the AT4X as well.
The AT4 and AT4X trims for the 2026 GMC Sierra HD are built for off-roading and other extreme situations. The truck is ideal for drivers who need to haul a heavy load and go off the pavement. It’s also a practical solution for picking up a big load of cargo in Temecula and hauling it to Fallbrook. Go beyond El Cajon to the mountains or the desert with a truck that can tow an RV and handle any terrain.
Shop all our new models here at the dealership to see what we have in stock for you. Our sales team will show you the 2026 GMC Sierra HD AT4 and AT4X or help you build your new truck. Get prequalified or find out the value of your trade-in. Let us help you find a truck that fits your lifestyle. Contact us with questions or to set up an appointment for a test drive today.