13.4 GMC Premium Infotainment | Duramax® 6.6L Turbo Diesel V8 | AT4X Off-Road Package | Multi-Colour 15 Head-Up Display | Bose® Premium 12-Speaker Audio | Power Sunroof | Heated & Ventilated 16-Way Power Seats | Rear Camera Mirror The 2026 GMC Sierra 2500 AT4X Crew Cab 4WD, commanding in Onyx Black with a premium Obsidian Rush full-grain leather interior, stands as the ultimate expression of heavy-duty off-road capability and premium luxury. Under the hood lies the legendary Duramax® 6.6L Turbo Diesel V8 engine, generating immense torque for effortless hauling and trail crawling through a 3.42 rear axle ratio. This extreme terrain machine is factory-engineered with a specialized off-road suspension featuring Multimatic® DSSV spool-valve dampers, a rear electronic locking differential, digital variable steering, and a 2-speed active electronic Autotrac transfer case. The imposing exterior presence is detailed with animated LED projector headlamps, front LED fog lamps, premium floor liners, a factory spray-on bed liner, and heavy-duty 35 mud-terrain tires. The AT4X cabin is a first-class sanctuary of executive refinement, dominated by a 13.4 diagonal colour touchscreen GMC Premium Infotainment system with Google built-in, wireless Apple CarPlay, wireless Android Auto, and a reconfigurable 12.3 driver info centre. Audiophiles will appreciate the rich tones of the Bose® Premium Series 12-speaker sound system with Centerpoint® surround sound. Unrivaled luxury comfort is provided by 16-way power-adjustable front bucket seats featuring heating, ventilation, and premium leather surfaces, complemented by a heated leather-wrapped steering wheel, a power sunroof, dual-zone automatic climate control, and heated second-row outboard passenger cushions. Everyday functionality is further maximized by power-retractable assist steps with LED perimeter lighting, power-folding heated trailering mirrors, a power-sliding rear window, wireless device charging, and multiple 120V AC power outlets in both the instrument panel and cargo bed. On-road security and towing confidence reach the highest standards with the Sierra HD Pro Safety suite and advanced tracking networks. The AT4X comes equipped with a multi-colour 15 diagonal Head-Up Display, an integrated Rear Camera Mirror, a dedicated Bed View Camera, an included dealer/customer-installed Auxiliary Trailer Camera, and a comprehensive HD Surround Vision system with Hitch Guidance and Hitch View. Standard active protection technologies include Adaptive Cruise Control, Trailer Side Blind Zone Alert, Rear Cross Traffic Alert, Automatic Emergency Braking, and Lane Departure Warning. Complemented by the haptic Driver Safety Alert Seat and Front and Rear Park Assist, the 2026 Sierra 2500 AT4X represents an uncompromising blend of tactical off-road engineering and world-class luxury. Stock #T4299220 AMVIC LICENSED DEALER