New 2026 GMC Sierra 3500HD AT4

The 2026 GMC Sierra 3500HD AT4 combines heavy-duty diesel capability, premium comfort, and rugged off-road confidence into one exceptionally capable pickup. Built to tackle demanding workloads, tow with authority, and explore beyond the pavement, this Sierra HD delivers strength, technology, and refinement without compromise. 

Performance & Capability 

• Engine: Duramax® 6.6L V8 Turbo-Diesel delivering impressive torque, towing capability, and long-haul durability 

• Transmission: Allison® 10-Speed Automatic Transmission engineered for smooth shifting and optimized power delivery 

• Drivetrain: Autotrac® Two-Speed 4-Wheel Drive system for confident traction in changing terrain and weather conditions 

• Off-Road Suspension: AT4-tuned suspension with factory lift and enhanced ground clearance for superior trail performance 

• Rear Differential: Automatic Locking Rear Differential maximizes traction on loose, uneven, or slippery surfaces 

• Hill Descent Control: Maintains controlled speeds on steep grades for added confidence off-road 

• Skid Plates: Underbody protection for critical components when venturing off the beaten path 

• Exhaust Brake: Integrated diesel exhaust brake enhances control and confidence while towing heavy loads 

• Axle Ratio: 3.42 rear axle ratio optimized for towing performance and highway efficiency 

• Trailering Equipment: Heavy-duty trailering package with integrated trailer brake controller and hitch guidance 

• Gooseneck/5th Wheel Prep Package: Factory-installed capability for serious towing and hauling requirements 

• Trailer Camera Provisions: Expanded visibility options to simplify towing larger trailers 

Winter & Weather Comfort 

• Heated & Ventilated Front Seats provide year-round comfort in every season 

• Heated Rear Outboard Seats keep rear passengers comfortable during colder months 

• Heated Steering Wheel adds warmth on chilly mornings 

• Remote Start System allows the cabin to be warmed or cooled before you enter 

• Dual-Zone Automatic Climate Control provides personalized comfort for driver and passenger 

• Engine Block Heater supports reliable cold-weather starts 

• Rain-Sensing Windshield Wipers automatically adjust to changing weather conditions 

• Winter Grille Cover helps maintain optimal engine temperatures during extreme cold 

Interior Comfort & Convenience 

• Front Bucket Seats with Power Driver and Power Passenger Adjustments for personalized comfort 

• Premium Jet Black Interior with Kalahari Accents creates a rugged yet upscale cabin atmosphere 

• Memory Settings for Exterior Mirrors provide added convenience for multiple drivers 

• Power Sliding Rear Window improves ventilation and accessibility 

• Rear Seat Storage Package adds practical cargo flexibility inside the cabin 

• Wireless Charging keeps compatible devices powered without cables 

• Push-Button Start and Keyless Open offer seamless access and operation 

• Multiple USB Ports throughout the cabin provide convenient charging and connectivity 

• 120-Volt Power Outlets in both the cabin and cargo bed support tools, devices, and accessories 

• Universal Home Remote adds everyday convenience 

Technology & Connectivity 

• GMC Premium Infotainment System featuring a 13.4-inch touchscreen with Google Built-In compatibility 

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

• 12-Inch Reconfigurable Digital Driver Information Centre delivers key vehicle information with customizable displays 

• Bose® Premium Audio System provides rich, immersive sound quality 

• Wireless Phone Projection keeps navigation, calls, and media easily accessible 

• Head-Up Display projects key driving information directly into the driver's line of sight 

• Rear Camera Mirror provides an expanded rearward view for enhanced visibility 

Safety & Driver Assistance 

• Sierra HD Pro Safety Suite designed to help increase driver awareness and confidence 

• Forward Collision Alert with Automatic Emergency Braking 

• Lane Departure Warning to help maintain intended lane position 

• Front Pedestrian Braking for added urban driving protection 

• Adaptive Cruise Control for more relaxed highway travel 

• Following Distance Indicator helps maintain safer spacing from vehicles ahead 

• Driver Safety Alert Seat provides intuitive warning feedback 

• Rear Cross Traffic Alert enhances awareness when reversing 

• Trailer Side Blind Zone Alert assists when towing larger trailers 

• HD Surround Vision offers a comprehensive bird’s-eye view around the truck 

• Front and Rear Park Assist helps simplify maneuvering in tight spaces 

• Teen Driver Technology encourages safer driving habits 

• Buckle to Drive safety feature promotes seatbelt use before driving 

Exterior Styling & Utility 

• Exterior Colour: Coastal Dune — a distinctive and sophisticated finish that complements the AT4’s rugged character 

• 20-Inch Black Aluminum Wheels paired with aggressive all-terrain tires for bold styling and off-road capability 

• Signature LED Headlamps, LED Fog Lamps, and LED Roof Marker Lamps provide exceptional visibility 

• Spray-On Bedliner enhances cargo box durability and protection 

• GMC MultiPro Tailgate offers versatile functionality for loading, unloading, and cargo management 

• LED Cargo Bed Lighting improves visibility when working after dark 

• Off-Road High-Clearance Assist Steps provide easier access while maintaining trail-ready capability 

• Power Sliding Rear Window and Deep-Tint Glass enhance comfort and appearance 

• Red Front Recovery Hooks add functional off-road confidence and unmistakable AT4 styling 

Whether you're hauling heavy equipment, towing a large RV, navigating challenging worksites, or exploring remote destinations, the 2026 GMC Sierra 3500HD AT4 delivers exceptional diesel power, premium comfort, advanced technology, and rugged capability. It’s the ultimate heavy-duty truck for drivers who demand professional-grade performance without sacrificing refinement.