The *2025 GMC Sierra 3500HD AT4 4WD Crew Cab Pickup* is a powerhouse of strength, durability, and off-road capability, designed for those who need a heavy-duty truck that can handle the toughest challenges. This AT4 trim combines *rugged performance, premium interior comfort, and advanced technology*, making it the ideal choice for work, adventure, and everything in between. === The AT4 trim stands out with its black chrome grille, red recovery hooks, LED signature lighting, and 20-inch all-terrain wheels. The spray-on bedliner, MultiPro tailgate, and integrated trailering mirrors add both functionality and style. Heavy-duty skid plates protect the underbody, making this truck ready for the roughest terrains. === === Powered by a high-output 6.6L Duramax Turbo-Diesel V8 engine paired with an Allison 10-speed automatic transmission, the Sierra 3500HD AT4 delivers unparalleled towing capacity and torque. The Autotrac 4WD system, off-road suspension with Rancho shocks, and locking rear differential ensure optimal control and traction on any terrain. With best-in-class trailering technology, including ProGrade Trailering System and Trailer Sway Control, hauling heavy loads has never been easier. === === Inside, the AT4-exclusive Jet Black and Kalahari leather-appointed seats, real aluminum accents, and heated and ventilated front seats create a refined yet durable cabin. A heated steering wheel, dual-zone automatic climate control, and power-adjustable pedals add to the comfort, making long drives effortless. The AT4 badging and contrast stitching highlight the truck’s off-road personality. === === The 13.4-inch touchscreen infotainment system features Apple CarPlay, Android Auto, Google Built-In, and a premium Bose sound system. A 15-inch head-up display, fully digital driver information center, and wireless charging keep you connected and in control. The MultiPro Audio System by Kicker turns your tailgate into an entertainment hub for outdoor adventures. === === Equipped with GMC Pro Safety, this truck features: === *Forward Collision Alert & Automatic Emergency Braking* — Enhances safety on the road. *Lane Departure Warning & Lane-Keeping Assist* — Keeps you centered. *Adaptive Cruise Control* — Provides a smooth driving experience. *Surround Vision Camera System & Rear Cross-Traffic Alert* — Improves visibility in tight spaces. *Blind-Spot Monitoring with Trailer Coverage* — Keeps you aware of surroundings while towing.