The 2026 GMC Sierra 1500 AT4 comes from the factory with equipment specifically aimed at off-road capability while also including premium interior and technology features.
Its standard 3.0L Duramax Turbo-Diesel, 2-inch factory lift, Rancho monotube shocks and two-speed AutoTrac transfer case make the AT4 one of the most distinctive configurations in the Sierra 1500 lineup.
What Engine Comes Standard in the Sierra 1500 AT4?
The 3.0L Duramax Turbo-Diesel engine with a 10-speed automatic transmission is standard on the 2026 Sierra 1500 AT4.
GMC also offers a 6.2L V8 with a 10-speed automatic transmission on the AT4, giving shoppers a gasoline V8 option within the same off-road-focused trim.
What Off-Road Equipment Comes With the AT4?
Standard AT4 capability equipment includes:
Suspension & Clearance
- 2-inch factory-installed suspension lift
- Off-road suspension
- Rancho monotube shocks
Traction & Protection
- Two-speed AutoTrac transfer case
- Underbody skid plates
- Hill Descent Control
GMC says both the AT4 and AT4X use the 2-inch suspension lift to provide additional clearance for off-road driving.
What Is the Interior Like?
The AT4 combines its off-road equipment with a premium cabin.
The 2026 Sierra 1500 AT4 includes a Jet Black interior with Kalahari accents and heated and ventilated perforated front leather seating surfaces.
Technology includes:
- 13.4-inch Premium GMC Infotainment System
- Google built-in compatibility
- 12.3-inch Driver Information Center
An available 15-inch multicolor Head-Up Display can add another driver-focused display.
What Other Features Come With the AT4?
The AT4 also brings together several features useful beyond the trail, including Adaptive Cruise Control, available camera technology and trailering technology depending on equipment. GMC offers up to 14 available camera views in the Sierra 1500 lineup.
What This Means for AT4 Shoppers
The AT4 is useful to research as a complete package rather than simply as an appearance trim. The factory lift, off-road suspension, Duramax engine, premium seating and large digital displays are all part of what gives it its place in the Sierra lineup.
Browse current 2026 GMC Sierra 1500 AT4 trucks at Dave Sinclair Buick GMC in St. Louis or contact our team for help finding a specific AT4 configuration.
