Zac Quinn 
GMC has just debuted the next generation GMC Sierra HD trucks, and though that’s quite exciting, we couldn’t help but let our eyes draw to another announcement as part of the 2024 Sierra HD product line. The off-road optimized Sierra HD AT4X trim is scheduled to arrive later in 2023 – a few months after the refreshed 2024 GMC Sierra HD comes to dealers in the first quarter of next year,.
2024 GMC Sierra HD AT4X: Details
Though the reveal of the 2024 GMC Sierra HD trucks didn’t come with any further information beyond the confirmation that there is, in fact, an AT4X trim on the way, we do know some details about this upcoming HD truck, as MC&T was first to exclusively report on the development of both this truck as well as the upcoming 2024 Chevrolet Silverado HD ZR2. The Sierra HD AT4X will come with a 35-inch Goodyear Wrangler Territory MT tire, which should pay some significant dividends when it comes to ground clearance, approach/departure/breakover angles, and overall traction off-road.
Additionally, the 2024 GMC Sierra HD AT4X will offer both the L8T 6.6L pushrod gasoline V8 and L5P 6.6L Duramax diesel V8 engines, which is a powertrain combo that the class-leading Ram Power Wagon doesn’t offer. Spy photos have emerged of the rugged truck out testing with some great angles that have enabled us to see the skid plates and suspension elements applied to the vehicle. The GMC Sierra HD AT4X prototype we’ve seen doesn’t feature any running boards, and it looks like it also doesn’t have any rocker guards to protect the sides from damage.
Future buyers of the 2024 Sierra HD AT4X can have peace of mind that the test vehicles have been put through their paces as one prototype spotted has taken a beating, but the underbody protection of the truck seems to do its job well. Regarding suspension for the upcoming truck, the Multimatic DSSV dampers are either darkened out – as they’re usually a golden color – or GM is looking into adding a different setup for the hefty truck.
