The GMC Sierra is set for some big updates soon, including the addition of Super Cruise for the 2022 model. But in the meantime, those looking for a little more have had access to the AT4 model, a version of the truck with a bunch of off-road performance upgrades. Earlier this month, we learned that Chevy Colorado buyers could expect a hardcore AT4X model in 2023 too, and now it seems that the range-topping trim will be added to the 2022 Sierra too. According to GM Authority, this new model will be based on the 1500 Limited and will obviously slot in above the regular AT4.

According to the rumors, the regular AT4, tagged as equipment group 4SB, will be joined by the AT4X as equipment group 4SG. Absolutely no other details have emerged, but we expect to see larger tires, DSSV dampers, unique badges, and possibly an all-black theme. Underbody protection and perhaps a unique front fascia could feature too, while the interior will likely boast more technology and luxury. Of course, these changes will look especially attractive with the 2022 Sierra about to be refreshed with new looks, a revamped interior, and more advanced driver assistance tech. That said, the AT4X may yet be applied to the older design, as the 2022 Sierra 1500 Limited is expected to be a stop-gap before the fully refreshed model arrives.

It's not yet clear exactly what the hardcore Sierra will be like, but we doubt that the recent teasing of a hardcore Silverado ZR2 from Chevy is a coincidence. After all, the Sierra and Silverado are virtually identical, so it would make sense to maximize returns. The Silverado ZR2 was teased in a very short video lasting all of 15 seconds, so all we can confirm at this point is a set of Goodyear Wrangler tires wrapped around new wheels. The teaser also seems to show a raised ride height, as you'd expect. Either way, if the Sierra AT4X is real, we'll surely learn more about it very soon.