2024 GMC Sierra HD ups power, luxury, and off-road mojo

GMC’s bold, burly Sierra HD truck is getting a major facelift and interior upgrade for 2024 along with powertrain changes that increase its towing capacity. Also, for the first time ever, the 2024 Sierra HD will offer Denali Ultimate and AT4X trims for buyers who demand more luxury and more off-road confidence, respectively.

All 2024 Sierras HD models will flaunt an updated face, with new grille, headlight, and bumper designs across all trim levels, from the work-centered Pro through the plush, new Denali Ultimate. Standard safety features include forward collision alert, lane departure warning, automatic emergency braking, auto high beams, and following-distance indicator. New for 2024 is standard front pedestrian braking.

Inside, Pro models will continue to use the same interior found in current HD models, but SLE models and above will receive updated interiors based on the fantastic mid-cycle update that rolled out to Sierra 1500 models in 2022. That means all trucks save the Pro models will get GMC’s 13.4-inch-diagonal, tablet-style touchscreen.

Combining brute power with leather-wrapped luxury, the Sierra HD Denali Ultimate will take the same upscale approach that we appreciated in the 1500 Denali Ultimate and apply it to the brawny 2500 and 3500 Sierras. The Denali Ultimate puts full-grain leather on the front seats, rear seats, and door panels, the last of which also receive etched stainless-steel speaker grilles. The front seats are 16-way adjustable and include a massage feature. Further luxury touches include a 12-speaker Bose audio system; microsuede upholstery on the headliner, visors, and A- and B-pillar trim; a standard power sunroof; and a standard 15-inch multicolor head-up display.

GMC was light on details of the off-road-oriented AT4X model, which will follow later in 2023. If the 1500 AT4X is any indication, we can expect a taller ride height, improved approach angle, and, hopefully, locking front and rear differentials. We’re hoping for a Super Duty Tremor competitor that can really tackle some difficult terrain. For now, we’ve got plenty of photos of the AT4 that show the mid-range off-roader looking good with its new fascia and interior.

The Sierra will, as expected, use the same 6.6-liter V-8s and 10-speed Allison automatic transmissions as its Silverado HD platform mate. The 6.6-liter gasoline V-8 remains, with 401 horsepower and 464 lb-ft of torque, but now comes with the 10-speed auto rather than its previous six-speed auto, allowing the engine to stay closer to its peak power output when upshifting.

The 6.6-liter Duramax diesel now produces 470 hp at 2800 rpm, up from the previous Duramax’s 445 hp output, and 975 lb-ft of torque at just 1600 rpm. Low-end torque has been increased by as much as 25 percent thanks to a new turbocharger and cylinder head castings that improve cooling and work with new injectors that operate at an even higher pressure. The result is more torque across the engine’s operating range for increased pulling power. That new turbo also adds improved engine braking capability to tame loads on long grades.

The extra power will allow for up to 21,900 pounds of towing on 2500HD Crew Cab and up 36,000 pounds on 3500HD. That impressive tow rating also comes with a host of towing tech to help the driver stay informed and feel confident. GMC’s ProGrade trailering system offers up to 14 camera views including an available “transparent trailer view” that stitches camera views from the back of the truck and the back of the trailer to give the driver a more complete view of what’s going on behind the truck. GMC’s adaptive cruise control can be used while towing and will account for the trailer’s additional mass and drag to plan its braking and acceleration. Like its Chevrolet counterpart, the Sierra HD will monitor acceleration and throttle position to determine if the truck’s gross combined weight has been exceeded and warn the driver.

GMC hasn’t shared any pricing details yet. Expect these updated Sierra HDs in showrooms in the first quarter of 2023, with the AT4X not far behind.