2026
GMC SIERRA 2500HD AT4 4X4 CREW CAB 6.75 FT. BOX

The 2026 GMC Sierra 2500HD AT4 is where uncompromising heavy-duty strength meets premium off-road refinement. Built for drivers who work hard, travel far, and explore beyond the pavement, this truck delivers commanding diesel performance, advanced technology, and a bold AT4 presence that looks as capable as it performs. 

Performance & Heavy-Duty Capability 

• Duramax® 6.6L V8 Turbo Diesel delivering immense torque and confident pulling power for the toughest jobs 

• Heavy-duty 10-speed automatic transmission engineered for smooth, controlled performance under load 

• Autotrac® two-speed 4-Wheel Drive system for confident traction across gravel, snow, mud, and steep terrain 

• 3.42 rear axle ratio optimized for towing strength, hauling confidence, and long-term durability 

• Integrated exhaust brake for improved downhill control and reduced brake wear 

• Automatic locking rear differential for sure-footed traction when conditions get challenging 

• Advanced trailering equipment with integrated trailer brake controller, hitch guidance, and in-vehicle trailering tools 

• Gooseneck and fifth-wheel prep for serious towing demands 

AT4 Off-Road Confidence 

• Factory-tuned off-road suspension with increased ground clearance 

• Skid plates protecting critical underbody components when venturing off the beaten path 

• Hill Descent Control for steady, controlled descents on steep or uneven terrain 

• Red front recovery hooks adding both functional strength and signature AT4 styling 

• 20" black aluminum wheels wrapped in aggressive all-terrain tires for confident grip on and off-road 

• Off-road high-clearance assist steps for easy access in rugged environments 

Interior Comfort & Premium Design 

• Jet Black and Kalahari interior blending rugged durability with upscale craftsmanship 

• Heated and ventilated front seats for comfort in every season 

• Heated rear outboard seats and heated steering wheel for cold-weather driving 

• Power-adjustable front seats with memory settings for personalized comfort 

• Dual-zone automatic climate control with rear air vents for balanced cabin comfort 

• Power sliding rear window and rear seat storage package adding versatility for work or travel 

• Wireless charging pad and multiple USB and 120V power outlets to support modern devices and tools 

• Remote start system to pre-warm or cool the cabin before you step inside 

Technology & Connectivity 

• 13.4" GMC Premium Infotainment Touchscreen with Google built-in and navigation capability 

• Wireless Apple CarPlay® and Android Auto™ for seamless smartphone integration 

• 12" reconfigurable digital driver information display with customizable views 

• Multicolor head-up display projecting key information directly into your line of sight 

• Bose® premium audio system delivering rich, immersive sound 

• HD Surround Vision and Bed View Camera for enhanced visibility when maneuvering or trailering 

Safety & Driver Assistance 

• Sierra HD Pro Safety technologies designed to enhance awareness and confidence 

• Forward Collision Alert with Automatic Emergency Braking 

• Lane Departure Warning and Following Distance Indicator 

• Front and Rear Park Assist for easier maneuvering in tight spaces 

• Trailer Side Blind Zone Alert and Rear Cross Traffic Alert 

• Teen Driver Mode and Buckle-to-Drive for added peace of mind 

Exterior Styling & Utility 

• AT4-exclusive design with dark accents and aggressive, purpose-built detailing 

• Exterior Color: Onyx Black, delivering a bold, commanding, and unmistakably premium presence 

• Signature LED headlamps, fog lamps, cargo bed lighting, and roof marker lamps for maximum visibility 

• GMC MultiPro™ Tailgate offering multiple configurations for loading, stepping, and worksite versatility 

• Spray-on bedliner and 120V bed-mounted power outlet for real-world work capability 

• EZ Lift power tailgate with power lock and release for added convenience 

• Perimeter and task lighting to illuminate worksites, campsites, and trails after dark 

From heavy hauling and serious towing to remote off-road adventures, the 2026 GMC Sierra 2500HD AT4 delivers relentless diesel power, advanced technology, and authentic off-road capability. It’s a heavy-duty truck with premium attitude—engineered to handle the toughest challenges while keeping you confident, comfortable, and in complete control.