• 2024 Sierra models will come standard with a 10-speed gearbox
• Optional turbocharged V8 diesel's output increased to 470 horsepower and 975 lb-ft of torque
• The new Denali Ultimate trim claims to be the most luxurious truck in its segment
• An off-road optimized Sierra HD AT4X trim will follow later in the model year

Chevrolet recently unveiled the all-new 2024 Silverado HD, including the very first HD ZR2, which we still don't know much about. Once Chevy's time in the spotlight was done, we knew it would only be a matter of days before GMC went live with the all-new Sierra HD, and here it is.

While Chevy is going in an off-road direction, GMC's focus is on luxury with a new Sierra Heavy Duty Denali Ultimate trim. An off-road optimized Sierra HD AT4X trim will follow later in the model year. Unfortunately, GMC did not provide more insight and is just as stingy as Chevrolet with information.

"The new and enhanced 2024 Sierra HD builds on an already winning foundation," said Duncan Aldred, vice president of Global Buick and GMC. "This truck elevates the HD segment with the introductions of the Denali Ultimate trim and will soon add the seriously off-road capable AT4X trim, further strengthening the dominance of the GMC truck portfolio."

The enhancement most heavy-duty customers will be interested in is the optional 6.6L Duramax turbocharged V8 diesel, now mated to a 10-speed Allison transmission. The engine produces 470 horsepower and 975 lb-ft of torque, up from 445 hp and 910 lb-ft. According to GMC, the updated engine provides 25% more low-down grunt.

As a result, the towing capacities have increased. The GMC Sierra HD can tow up to 21,900 pounds in 2500HD Crew Cab configuration (Long Bed 2WD) and up to 22,500 lbs for the 2500HD. That's a 4,000-lbs improvement over the current model. The 3500HD can tow up to 36,000 lbs when equipped with a gooseneck hitch and the V8 diesel engine.

The 2024 Sierra HD lineup includes 2500HD and 3500HD models in Regular Cab, Extended Cab, and Crew Cab configurations - with dual-rear-wheel models available on 3500HD.

The 6.6-liter naturally aspirated gas engine carries on as standard fitment. It's also mated to the new 10-speed transmission, which should improve the trailering experience. The wider spread of gear ratios will help the car stay closer to peak power while improving fuel consumption. Its output is rated at 401 hp and 464 lb-ft of torque, which is the same as before.

GMC is also introducing a host of trailering assistance technologies, just like Ford did with the new F-Series Super Duty. The available tech here includes Transparent Trailer View, Trailer Side Blind Zone Alert, Adaptive Cruise Control with Trailering, and GCW Alert. The latter will warn the driver if the vehicle and trailer weight exceeds the vehicle's Gross Combined Weight Rating.

The truck can also be equipped with up to 14 cameras, providing guidance for the hitching process, a view of the bed, and a camera that will display the view down the side of the truck with the trailer length included.

Standard safety systems across the range include Forward Collision Alert, Lane Departure Warning, Automatic Emergency Braking, Front Pedestrian Braking (new for 2024), IntelliBeam auto high beams, and Following Distance Indicator.

The interior is enhanced by the available 13.4-inch diagonal touchscreen interface, 15-inch head-up display, and 12.3-inch digital instrument cluster. The large infotainment screen can be customized and can run navigation on one side and media on the other. It comes standard with Google built-in and wireless Apple CarPlay and Android Auto.

Exterior upgrades include a revised front bumper, fascia, grille designs, and finishes on each trim. There are new wheel designs and six new exterior colors. These new options are Titanium Rush Metallic, Sterling Metallic, Volcanic Red Tintcoat, Redwood Metallic, Meteorite Metallic, and Downpour Metallic.

The Denali Ultimate is claimed to be the most advanced and luxurious pickup in its class. It comes standard with the V8 diesel, a model-specific grille, 20-inch Ultra-bright machined aluminum wheels with High Gloss black accents, and unique fender badging featuring the topography of Mount Denali. A six-way Multipro tailgate with a Kicker sound system is also standard.

On the inside, it gets full-grain leather appointments and open-pore Paldao wood, etched stainless steel speaker grilles, 16-way power-adjustable and massaging front seats, microsuede headliner, power sunroof, and a 12-speaker Bose sound system.

The refreshed 2024 GMC Sierra HD arrives at dealerships in the first quarter of 2023, with the AT4X coming later in 2023. Pricing will be announced closer to the start of production.