3.0L Duramax turbo-diesel inline-6: 277 hp and 460 lb-ft torque paired with a 10-speed automatic.
Strong towing for a half-ton: up to 9,000–9,100 lb towing and 1,380 lb payload.
Excellent fuel economy for a full-size truck: about 20/23 MPG city/highway (21 combined).
Long driving range of roughly 480–550 miles per tank.
👉 Big highlight: it blends torque-rich towing power with diesel efficiency — rare in a full-size off-road truck.
The AT4 is the factory off-road trim:
2-inch factory suspension lift and off-road tuned suspension.
Two-speed transfer case, hill descent control, and auto-locking rear differential.
Skid plates, red recovery hooks, mud-terrain tires.
Standard 4WD and heavy-duty electrical/charging system for towing and off-road use.
This makes it one of the most capable off-road half-ton diesels available.
ProGrade Trailering System with in-vehicle trailering app.
Hitch Guidance with Hitch View and integrated trailer brake controller.
Tow/haul mode with grade braking for safer downhill towing.
These features make towing easier for beginners and pros alike.
AT4 mixes rugged with luxury:
Heated & ventilated front seats with power adjustments and memory.
Leather interior and massaging front seats available.
Large crew-cab interior with generous rear legroom.
It’s designed to be both a daily driver and adventure truck.
GMC Premium Infotainment System with 8-inch touchscreen.
Wireless Apple CarPlay & Android Auto.
Voice recognition, Bluetooth streaming, SiriusXM, and connected apps.
Lane departure warning, lane keep assist, and forward collision prevention.
Modern driver-assist features designed for highway and towing safety.
The 2022 Sierra AT4 Duramax stands out for combining:
Diesel fuel economy
Real off-road hardware
Strong towing tech
Premium comfort and tech
It’s one of the most balanced adventure + daily-driver half-ton trucks you can get.