Key Features of the 2026 GMC Sierra 2500 HD

Duramax 6.6L Turbo-Diesel V8

For frequent towing and steep grades, the available Duramax 6.6-liter turbo-diesel V8 is the powertrain to beat. It pushes out 470 horsepower and a towering 975 lb-ft of torque, channeling that force through a 10-speed automatic. The combination builds confident acceleration off the line, reassuring midrange performance for passing, and relaxed, low-RPM cruising when your trailer is hooked. Tested in the Sierra 2500HD lineup, the diesel powertrain has shown impressive composure for its size, posting a 0–60 mph time of 6.6 seconds in comparable trims. Beyond straight-line pace, the diesel’s smoothness stands out—torque arrives early and predictably, so merging with traffic or easing up a boat ramp feels natural. If your calendar includes frequent hauls or you’re stepping up to fifth-wheel or gooseneck setups, the Duramax delivers the kind of effortless pull that reduces driver fatigue and inspires confidence mile after mile.

6.6L Gas V8

The standard 6.6-liter gas V8 provides 401 horsepower and 464 lb-ft of torque, striking a strong balance of capability and simplicity for mixed-use owners. Paired with the same 10-speed automatic as the diesel, the gas V8 is responsive and predictable under varying loads. For operators who split time between jobsite tasks, supply runs, and personal errands, it’s a smart, value-forward choice that still handles demanding work. When configured correctly, the 2026 GMC Sierra 2500 HD with the gas V8 remains a confident tower, and the wide-ratio 10-speed keeps the engine in its sweet spot. Owners who prefer straightforward maintenance and readily available fuel will appreciate how this powertrain integrates into daily routines without sacrificing core heavy-duty performance.

10-Speed Automatic Drivetrain

Both Sierra 2500 HD engines utilize a 10-speed automatic transmission that’s tuned for heavy-duty duty cycles. The closely spaced ratios help keep the gas and diesel V8s right in their optimal torque bands—especially helpful when towing or climbing grades. The gearbox’s programming also contributes to a more settled driving feel at highway speeds, minimizing hunting and helping you maintain momentum with fewer shifts. Rear-wheel drive configurations emphasize payload and towing efficiency, while available four-wheel drive adds traction and control in inclement weather or on unpaved access roads. The overall driving experience is more agile than you might expect in a heavy-duty truck of this size, a testament to well-matched gearing and chassis tuning that prioritizes stability without dulling responsiveness.

MultiPro Tailgate

GMC’s MultiPro tailgate continues to be one of the most useful bed innovations on any pickup, and availability expands even further for 2026. With six distinct functions, it transforms from a traditional tailgate into a workspace, a load stop, a step, and more—all without additional accessories. Those touches matter when you’re loading irregular cargo, organizing tools, or climbing in and out of the bed repeatedly during the day. Combined with bed steps integrated into the bumpers and aft of the doors, the Sierra 2500 HD makes accessing the box less of a chore. You can further outfit the bed with movable tie-downs, a 120-volt outlet, and LED lighting, creating a cargo area designed for early starts and late finishes. For owners who do real work with their truck, the MultiPro tailgate is the difference between “making it work” and having the right tool for the job.

ProGrade Trailering with 15 Camera Views

Backing into tight campsites, aligning a heavy trailer on a windy day, or passing on two-lane roads—all get easier with GMC’s available camera system that supports up to 15 views. From a top-down perspective for parking to angles that help you check bed cargo or look down the sides of your trailer, this system turns difficult maneuvers into routine tasks. Hitching assistance and clear guidelines speed up connections, while additional views help you monitor trailer position and surroundings as you move. Owners stepping into heavier fifth-wheel or gooseneck setups will appreciate the confidence these perspectives bring, and those who tow less frequently will value how quickly the system flattens the learning curve. It’s practical technology that directly improves safety, efficiency, and peace of mind every time you tow.