Used 2026 GMC Sierra 2500HD AT4

2026 GMC Sierra 2500 AT4 Crew Cab 4WD | Duramax Diesel, Allison Transmission, AT4 Premium Plus, and Heavy-Duty Off-Road Capability

If you’re searching for a new GMC Sierra 2500 AT4 for sale in Ontario, a heavy-duty Duramax diesel truck near Bancroft, a premium 4WD work truck with luxury comfort, or a serious towing truck built for cottage country, job sites, trailers, snow, and heavy hauling, this 2026 GMC Sierra 2500 AT4 Crew Cab 4WD is built to deliver.

Finished in Onyx Black with a Jet Black and Kalahari interior, this Sierra 2500 AT4 has the bold look, heavy-duty strength, and upscale equipment that truck buyers are actively looking for. Power comes from the legendary Duramax 6.6L V8 Turbo Diesel paired with the Allison 10-speed automatic transmission, one of the most respected heavy-duty powertrain combinations on the market.

For shoppers comparing heavy-duty diesel trucks, the Duramax and Allison pairing is one of the biggest hot buttons. It brings serious pulling confidence, smooth power delivery, long-distance highway strength, and the kind of torque buyers want when towing campers, equipment trailers, boats, enclosed trailers, work gear, or anything else that needs real muscle.

This AT4 also brings the off-road confidence buyers expect from the GMC AT4 name. With 4WD, a 2-speed Autotrac transfer case, auto-locking rear differential, Digital Variable Steering, Stabilitrak with trailer sway control, hill start assist, skid-ready AT4 attitude, and a heavy-duty frame, this Sierra is ready for Ontario winters, gravel roads, construction sites, camp roads, and weekend adventures.

The AT4 Premium Plus Package adds major luxury and visibility features, including a power sunroof, Rear Camera Mirror, 15-inch multicolour Head-Up Display, power sliding rear window, Universal Home Remote, LED roof marker lamps, and power-retractable assist steps with LED lighting. These are exactly the features many premium truck shoppers look for when comparing Sierra AT4, Denali, Silverado HD, Ram 2500, and Ford Super Duty models.

Inside, this Sierra 2500 AT4 is built for long days and long drives. Heated and ventilated front seats, heated rear outboard seats, Adaptive Cruise Control, wireless charging, Bose Premium speakers, premium floor liners, dual-zone automatic climate control, driver memory settings, a heated steering wheel, 120V power outlets, and a 12.3-inch reconfigurable driver display make the cabin feel comfortable, modern, and highly functional.

Technology is a major strength. The 13.4-inch GMC Premium Infotainment touchscreen with Google Built-In, navigation capability, wireless Apple CarPlay, wireless Android Auto, Bluetooth, SiriusXM trial, OnStar Basics, remote start, and the in-vehicle trailering app gives drivers the connected experience expected in a premium heavy-duty truck.

For towing, hauling, and work use, this Sierra is very well equipped. It includes a factory trailering package with Hitch Guidance and Hitch View, integrated trailer brake controller, Trailer Side Blind Zone Alert, Bed View Camera, HD Surround Vision, gooseneck and 5th wheel prep package, snow plow prep and camper package, high idle switch, spray-on bedliner, LED cargo bed lighting, 120V bed outlet, MultiPro Tailgate, and EZ-Lift power lock and release tailgate.

Safety is another major selling point with Sierra HD Pro Safety, including Automatic Emergency Braking, Forward Collision Alert, Front Pedestrian Braking, Lane Departure Warning, Following Distance Indicator, IntelliBeam auto high beams, Front and Rear Park Assist, Rear Cross Traffic Alert, Safety Alert Seat, HD Surround Vision, and Trailer Side Blind Zone Alert.

For drivers who need a truck that can work hard, tow confidently, handle rough weather, look sharp, and still deliver premium comfort, this 2026 GMC Sierra 2500 AT4 Duramax is an outstanding heavy-duty choice at Boyer Chevrolet Buick GMC Bancroft.

Top Features

Duramax 6.6L V8 Turbo Diesel Allison 10-Speed Automatic Transmission AT4 Premium Plus Package Gooseneck and 5th Wheel Prep Package Snow Plow Prep and Camper Package 15-Inch Head-Up Display Rear Camera Mirror Bed View Camera HD Surround Vision Adaptive Cruise Control Heated and Ventilated Front Seats Heated Rear Seats Bose Premium Speakers Wireless Apple CarPlay Wireless Android Auto MultiPro Tailgate Spray-On Bedliner Power Sunroof Power-Retractable Assist Steps Trailer Brake Controller.

Save more with this Boyer GM demonstrator vehicle at Boyer Chevrolet Buick GMC Bancroft. With only a small amount of dealership-driven mileage, these near-new vehicles qualify for larger discounts while still offering the same great new vehicle finance rates, warranty coverage, incentives, and manufacturer programs.