GMC is giving its heavy-duty pickup trucks a big upgrade for 2024. The GMC Sierra HD models get more power and torque from their diesel engines, higher towing on 2500 models, and some handy towing tech upgrades. There's also a new Denali Ultimate trim for the first time on the HD trucks, part of a facelift and series of all-new cabins.
GMC's 6.6L Duramax diesel gets plenty more power and torque for 2024, 470 hp and 975 lb-ft, an increase from the 445 and 910 it made in 2023. On top of the higher peak figures, thanks to a new turbo, there is 25 per cent more torque at low RPM. The new turbo also lets GMC add better engine braking.
Gas power is unchanged as the 6.6L gas V8 makes the same 401 hp and 464 lb-ft as before, but one change should make better use of that power. The transmission is now a 10-speed, the same Allison unit that's paired with the diesel. With four more forward gears, the engine should be able to deliver better fuel economy as well as a more pleasant driving experience, especially when loaded.
The 3500HD trucks see maximum towing unchanged at 36,000 lbs, but the 2500 trucks get a big upgrade. Those 3/4-ton pickups can now tow up to 22,500 lbs for regular and extended cab or 21,900 lbs for crew cabs. The former is 4,000 lbs more than last year, the latter best-in-class.
The new trucks also have new grilles that are as big and bold as you'd expect from a full-size HD pickup. Different trim levels get different treatments, including bright chrome on the Denali and Vader black chrome on the Denali Ultimate. There are new wheel designs to match the new face.
Inside, GMC has made most of the same changes as on the light-duty trucks. The new dashboard design finally offers competitively-sized screens, including an available 13.4-inch monster with a new Google-based software interface, a 12.3-inch digital dash, and a head-up display. GMC says it has gone more luxurious on finishes, especially for the Denali Ultimate, which gets full-grain leather on the seats, doors, and console, all in an Alpine Umber hue.
Other Ultimate upgrades include 16-way power-adjustable seats with massage up front, a 12-speaker Bose audio system, a power sunroof, and microsuede for the headliner, visors, and pillars.
GMC's Transparent Trailer View now works with fifth wheel and gooseneck trailers, making it handier on the HD trucks. Trailer side blind spot alert expands the blind spot warnings down the side of both truck and trailer, and the available adaptive cruise control can now handle the extra weight and drag that comes with a trailer. New for 2024 is GCW alert, which lets you know if you're going over your truck's gross combined weight rating.
The 2024 GMC Sierra 2500 and GMC Sierra 3500HD trucks will go on sale in the first quarter of 2023. Pricing will come closer to production start, and there will be an AT4X off-road special later in the year.