13.4 Diagonal GMC Infotainment w/ Google Built-In | Duramax® 6.6L V8 Turbo Diesel | AT4X Off-Road Suspension w/ DSSV Dampers | 15 Diagonal Head-Up Display | 16-Way Power Front Seats | Bose® Premium 12-Speaker System | Power Sunroof | Gooseneck/5th Wheel Prep Package The 2026 GMC Sierra 2500 4WD AT4X Crew Cab, presented in a commanding Onyx Black with a specialized Obsidian Rush interior, is the ultimate expression of heavy-duty off-road luxury. This powerhouse is driven by the high-torque Duramax® 6.6L V8 Turbo Diesel engine, paired with a smooth 10-speed automatic transmission. Engineered for extreme capability, the AT4X features a factory-installed off-road suspension with Multimatic DSSV dampers, a rear electronic locking differential, and a 2-speed active Autotrac transfer case. The interior offers an unparalleled premium experience, highlighted by 16-way power-adjustable front seats with massage features, all wrapped in exclusive Obsidian Rush leather. The cabin is packed with advanced technology, including a multi-color 15 diagonal Head-Up Display, a Rear Camera Mirror, and a 12.3 reconfigurable driver information centre. For the audiophile, the Bose® Premium Series 12-speaker system provides an immersive sound experience, while the 13.4 diagonal GMC Infotainment system with Google built-in keeps you seamlessly connected. Utility meets innovation with power-retractable assist steps featuring LED perimeter lighting, a spray-on bed liner, and the Gooseneck/5th Wheel Prep Package. Safety is at the forefront with HD Surround Vision, Bed View Camera, and Adaptive Cruise Control. Complete with animated LED projector headlamps, a power sunroof, and a power sliding rear window, this Sierra 2500 AT4X delivers world-class off-road performance without compromising on elite luxury. Stock #T4253413 AMVIC LICENSED DEALER