Heavy-duty off-roading at GMC had increased a notch with the first-ever Sierra 2500HD AT4X trim. And instead of stopping there, the automaker offers a special AEV Edition package on top of that with more steel, more badges, and a sterner appearance.

What sets the beefy AT4X apart from the standard Sierra HD? As with other AT4X models in GMC's lineup, this isn't an appearance package with badges and wheels. It sits an inch and a half higher thanks to a suspension lift. Multimatic DSSV dampers are plugged in, and it rides on 35-inch all-terrain tires. At the back is a new e-locking differential for the rear axle, while at the front, new upper and lower control arms are installed and connected to upgraded steering knuckles. And to keep things protected when venturing off the beaten path, a larger steel skid plate protects the transfer case. An aluminum skid plate is installed at the front.

Gallery: 2024 GMC Sierra HD AT4X AEV Edition

To further help all the upgraded components tackle tough terrain, GMC gives the Sierra HD AT4X a new Off-Road mode. The automaker is ambiguous with details about the programming of the system, stating it tweaks everything from the anti-lock brakes, stability and traction controls, throttle response, and shifting of the standard 10-speed Allison automatic transmission. The truck can still tow up to 18,500 pounds, and it's offered with either the 6.6-liter gasoline engine or the turbocharged 6.6-liter Duramax diesel. If you recall from the 2024 GMC Sierra HD debut in October 2022, it makes 470 horsepower and 975 pound-feet of torque.

For those wanting a bit more aggression in their off-roading Sierra HD, there's an AEV Edition that is primarily an appearance package. In addition to special badging, it adds trim-specific 18-inch wheels and new steel bumpers with a built-in winch and tow hooks. There's also more protection underneath thanks to heavy-duty steel skid plates. And whether you choose AT4X or AEV Edition, all trucks gain a special Obsidian Rush interior decked out with leather, massaging seats, and luxury features to make sure your hardcore adventure is softened at least a little bit.

GMC announced the Sierra HD AT4X back in October, but this is our first look at the truck in detail. Pricing still isn't available, however. Look for that to be announced closer to its on-sale date, coming in the fall of 2023.

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