The Car Connection GMC Sierra 2500HD Overview
The GMC Sierra 2500HD is a heavy-duty pickup that's related to the Chevrolet Silverado 2500HD. Like the Chevy, the GMC version is offered in three-quarter ton and one-ton configurations, with a high-buck Sierra Denali edition available both big trucks.
Where the Chevy Silverado heavy-duty range may skew toward work and fleet buyers, the GMC Sierra range is more often a luxury truck. The GMC Sierra Denali HD offers a heady mix of capability and luxury features that tempt buyers' wallets.
The Sierra HD was new for the 2020 model year, one year after the light-duty 1500 pickups were redesigned. Not much changed for 2021, aside from an off-road trim level and a even tonier Denali trim.
With the Sierra HD, GMC has rivals for the Ford Super Duty range and the Ram heavy-duty lineup.
MORE: Read our review of the 2020 GMC Sierra 2500HD
The new GMC Sierra HD
The 2020 GMC Sierra HD is bigger, more opulent, and more capable than ever. A series of cameras and other technology tools help it tow with more confidence, while new driver-assistance features make it safer.
The new Sierra HD comes with rear-wheel drive as standard or optional four-wheel drive. Regular, double and crew cabs are offered with standard and long beds. The beds are also wider and longer at 8-foot-2 inches and 6-foot-11 this time around to give them best-in-class capacity.
The Sierra 2500 HD rides on a wheelbase that is 4.5 inches longer, and it's 1.4 inches wider, 2 inches taller, and up to 11.5 inches longer. The bigger dimensions make it more commanding than ever. Despite the tall, blocky grille, the Sierra manages to look more coherent than its Chevrolet Silverado 2500HD sibling. Notable exterior features include LED headlights, side steps in front of the rear wheels, bed steps built into the rear bumper, an available carbon-fiber bed, and GM's MutliPro tailgate that can serve as a workbench, bed step, or seating spot and offers built-in speakers for tailgating.
The GMC Sierra HD is offered with a choice of two V-8s: one gas, one diesel. The gas version is a new 6.6-liter V-8 that makes 401 horsepower and 464 pound-feet of torque, up from 360 hp and 380 lb-ft over the previous 6.0-liter V-8. The lighter-weight gas engine offers the most payload capacity at 3,615 pounds. The turbodiesel 6.6-liter V-8 is the choice for towing. It produces 445 hp and 910 lb-ft of torque, and allows the GMC Sierra 2500HD to tow 18,500 pounds. The diesel is paired with a new Allison 10-speed automatic transmission, and the gas engine gets a 6-speed automatic.
Those who tow benefit from up to eight cameras that offer up to 15 camera views, including a hitch view to line up trailers, a bed view to monitor cargo, a split side view that identifies the position of the trailer in its lane, and a transparent trailer that shows the road behind the truck through an outline of the trailer. The transparent trailer view is enabled by an accessory camera mounted to the rear of the trailer.
Active safety features are creeping into HD trucks and the Sierra HD gets some of them. Blind-spot monitors, rear cross-traffic alerts, forward-collision warnings with automatic emergency braking, and lane-departure warnings join other safety equipment like front and rear park assist and GM’s rear camera mirror.
Buyers can opt for a variety of models, starting the the work-truck-like base, and moving through SLE, SLT, AT4, and Denali. The AT4 is the well-equipped off-roader. It comes with black trim, an off-road suspension, skid plates, and knobby tires, while the Denali has a chrome look and more amenities. Leather upholstery is standard on AT4 and Denali, as is an 8.0-inch touchscreen for infotainment and navigation.
Like other luxury trucks (and cars), the Sierra Denali HD starts well north of $70,000, but its popularity and growing list of interior refinements may be an indicator of how far truck buyers have come—and how far they're willing to go in the future.
GMC Sierra HD history
The GMC Sierra HD history is understandably linked to the Chevrolet Silverado HD range from which it's based.
GMC's heavy duty range goes back to the 1960s, when the truckmaker offered three-quarter and one-ton versions of their pickups, badged 1500 and 2500 with "K" denoting newly available four-wheel drive. Most of those heavy-duty trucks were powered by inline-6 engines, although a V-8 was made available toward the end of that generation.
The late-1960s and early-1970s marked a new generation for the big pickups, which were still reserved for commercial- or work-focused users. The "Sierra" name denoted a trim level on heavy-duty trucks, which applied to top trims for GMC. The truckmaker also shifted its naming convention to 2500 and 3500 for three-quarter and one-ton trucks, which endures today.
Those trucks were followed by a long-running series of pickups called the "square body" generation, powered predominately by V-8 gasoline engines, although a V-8 diesel engine was newly available. GMC updated its designs, inside and out, until the pickups were eventually retired in the late-1980s.
GMC Sierra's popularity soared in the 1990s with its GMT400-based pickups that, among other things, added an independent front suspension for a smoother ride. Although double cabs were available before the fourth-generation pickup, the Sierra's four-door version took off with consumers looking for a comfortable ride for a crew.
The K-named trucks were retired after that generation when GMC made the switch to the Sierra name for the entire range in 1998.
GMC found paydirt in 2002 when it changed the name of its top-trimmed Sierra C3 to "Sierra Denali." The next generation of GMC Sierra heavy-duty pickups traded on that success with increasing number of comfort features including the discontinuation of manual-equipped heavy-duty pickups.
The last-generation GMC Sierra HD arrived in 2014. While powertrains, frames, and suspension heavy-lifting had slowly made its way into the Sierra 2500HD before then, the truck was transformed when it adopted the interior from the light-duty range.
The base engine was a 6.0-liter V-8 and the optional 6.6-liter turbodiesel V-8 was updated in 2017 to make up to 910 lb-ft of torque and 445 hp, numbers that continue with this generation.
Both engines were paired to a 6-speed automatic transmission. GMC offered 8-foot or 6-foot-6 beds.
The GMC Sierra 2500 Denali HD proved to be a best-seller for the truckmaker thanks to its high level of features and quality interiors.