2026 GMC Sierra 3500HD AT4

Experience unmatched capability and comfort with the 2026 GMC Sierra 3500HD AT4, featuring a powerful Duramax 6.6L Turbo-Diesel V8, advanced safety, and premium off-road enhancements.

Built for demanding tasks, this Sierra 3500HD AT4 boasts a 470 hp, 975 lb-ft torque Duramax 6.6L Turbo-Diesel V8 engine paired with a smooth 10-speed automatic transmission and 4x4 drivetrain. The Gooseneck/5th Wheel Prep Package provides a versatile hitch platform for heavy towing needs, while the locking limited-slip differential ensures confident traction in challenging conditions. Exterior features include Coastal Dune paint, body-colour wheel arch mouldings, integrated tailgate step, running boards, and rugged on/off-road tires on aluminum wheels. Inside, enjoy premium comfort with leather bucket seats that are heated and cooled up front, heated rear seats, power-adjustable driver and passenger seats with lumbar support, and seat memory. The AT4 Premium Plus Package adds a power sunroof, advanced Technology Package, and Off-Road High Clearance steps for enhanced capability and convenience. Safety is comprehensive with features such as automatic high beams, blind spot monitoring, front collision mitigation, lane departure warning, and a full suite of airbags. Additional amenities include an aerial view display system, adaptive cruise control, heated mirrors, auto-dimming rearview mirror, and remote engine start, making this truck as smart as it is tough.