The 2024 GMC Sierra HD AT4X Will Let You Tow 18,500 Pounds To The Top Of Your Nearest Mountain

Sierra Hd At4x Topshot 1
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With the recent reveal of the Chevrolet Silverado HD ZR2, we had a feeling a GMC Sierra HD AT4X wasn’t that far away. Well here it is, GMC’s pumped-up heavy-duty pickup truck set to do battle with the Ford Super Duty Tremor and Ram 2500 Power Wagon. As with anything bearing the AT4X emblem, it’s a posh off-road rig, offering luxury adjacent to that of a Sierra Denali, but in a package meant more for national parks than cruising down the parkway. We’ve seen this treatment applied to the half-ton Sierra and midsize Canyon pickup trucks over the past few years, and now it’s going literally bigger than ever.

Sierra Hd At4x Damper

A modest 1.5-inch suspension lift should offer useful clearance over the rough stuff, and it’s not just a simple springs-and-shackles job. To keep geometry in check, GMC fit the Sierra HD AT4X with revised front controls arms and new knuckles. Multimatic’s trick spool-valve DSSV dampers are on deck to soak up whatever punishment these trucks endure.

While the first owners probably won’t abuse these dampers, the third owners are going to really have some fun once they lock the rear differential and send it over some rocks, or just put the pedal down over some dunes.

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Of course, you can have all the suspension in the world and still not have traction if your tires aren’t up to the task, so 35-inch Goodyear Wrangler Territory tires with plenty of sidewall offer reasonably knobbly tread and more than enough room to air down. The other big pieces of trail hardware are a steel skid plate for keeping rocks away from the transfer case and an aluminum front skid plate so you don’t get the nose caught on a boulder. Aluminum may sound like a strange material for a skid plate, but it should do a good job of deflecting rocks, and also rust belt drivers will enjoy how aluminum doesn’t rot like steel.

Sierra Hd At4x Aev 2

While the Sierra HD AT4X’s independent front suspension sounds like a capability disadvantage over its solid front axle-equipped competitors, I doubt it will ever be a real handicap. Given the sheer size of the truck, you’ll likely run out of trail before you run out of articulation, and that’s before we even get into limitations like breakover angle (which is related to overall size, admittedly). A 21.2-degree breakover angle trails the Ram Power Wagon’s 23.9-degree breakover angle, never mind what smaller rigs can offer.

If this all sounds extremely familiar, that’s because all the off-road hardware is the exact same stuff offered on the Chevrolet Silverado HD ZR2. The difference? Skip the bowtie badge and you get a truck that’s much easier to look at. Sure, you can house a family of five in the Sierra’s grille, but it’s somehow still less gaping that the Silverado’s maw.

Sierra Hd At4x Aev 1

In case excess is never enough, GMC will sell you an AEV-upfitted Sierra HD AT4X with heavier steel skid plates, special steel bumpers with room up front for a winch, new 18-inch wheels, and enough badges to let everyone know you’re driving something rugged. Plus, it bumps breakover angle to 22.6 degrees and ground clearance a tenth of an inch to 11.7 inches. Approach angle drops from 31.6 degrees to 29.8 degrees, but that’s not a bad trade for a winch-capable bumper. Plus, departure angle is unchanged at 25.7 degrees despite the beefier rear bumper.

Seats

On the inside, the Sierra HD AT4X takes a page from the Range Rover’s book by making going off-road extremely comfortable. We’re talking massaging full-grain leather seats, a 12-speaker Bose stereo, wood from actual trees, and more cameras than a bank branch. Perhaps more important than the luxury is how usable this kitted-out rig seems. You can still get it with a diesel engine (a 6.6-liter gasser is standard), it can still tow up to 18,500 pounds, and the bed isn’t rendered useless by a meaty spare tire. I wouldn’t be surprised to see this thing bogging through a muddy jobsite once it rolls into showrooms this autumn. Pricing hasn’t been announced yet, but don’t expect this beast to come cheap.

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Oh, and if you’re wondering what’s under the cover on the trailer towed by the AEV model, I’ll give you a few hints. It’s much smaller than a Sierra, has massive skid plates, and GMC calls it a “midsize surprise.” Yep, an even tougher version of the Canyon AT4X appears to be on its way.

(Photo credits: Thomas Hundal)

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48 thoughts on “The 2024 GMC Sierra HD AT4X Will Let You Tow 18,500 Pounds To The Top Of Your Nearest Mountain

    1. You don’t need a CDL for class A or B in all states, in CA you can get a non commercial license at those levels. Also, most Class D or C licenses are limited to GVWR of 26klbs, which doesn’t say anything about towing capacity. I remember my MN license said combinations up to 26k gvwr so it’s up to the individual person to make sure their total combination isn’t above their class. And

        1. In most states a commercial license is only required when you have a commercial purpose, the standard ABC covers private drivers. you would need at least a B class though for any trailer over 10k here in PA

  1. Battle Wagon! I’m sure there’s some use case for these trucks, but the styling has jumped the shark in a big way. Is that hood six feet high? Do you need a truck stop ladder rig to was the windshield? At some point they’re going to need Plexiglas foot-wells like on a helicopter so you can actually see in front of the truck while you’re driving. ‘Merica!

    On the hand, David could use one of these to tow an airport tug to the off road park.

  2. “While the Sierra HD AT4X’s independent front suspension sounds like a capability disadvantage over its solid front axle-equipped competitors, I doubt it will ever be a real handicap.”

    This is the correct take. You buy a 4WD capable truck (or a Yukon equivalent) like this for the ability to travel hundreds or thousands of miles comfortably hauling all your gear and passengers and perhaps a trailer to your adventure or work site or whatever in any weather. Then you want to be able to make it through whatever crappy road/trail/mild-ish off-road distance remains to get you to your goal destination. You’re not rock-crawling and doing hardcore 4-wheelin’ with a rig like this. Independent suspension gives you the highway ride you want and the somewhat lessened articulation simply doesn’t matter when your vehicle size, approach, departure and breakover are the real limiting factors in where you can go.

    In fact, I’ll go the other way. For the use case I listed above the lift and 35s aren’t doing you any favors on the highway. Proper all-terrain 31s/33s with no lift should be sufficient, although I’d still want the skid plates and the locking diffs.

    1. Yeah, most of the off-road pickups would be better with no extra lift, the same wheels as the regular 4×4, but the rest of the upgrades in place.

    2. The standard tire on everything but base models is 275/70/18, which is already over 33″.

      35s are not really much bigger; the description change from metric sizing to floatation is meant to conceal this (“Whoa, factory 35s, must be awesomeeee”).

      31s would look comically small.

      1. 31s would look comically small because the rest of the pickup is styled around big wheels(MURICA!!!!!). 31s don’t look comically small on a 90s 3/4 ton pickup.

        1. It’s more than just styling, I encourage you to panic stop a fully loaded 90s 3/4 ton and a current model. The bigger brakes are a godsend, and they don’t fit under 15 or 16″ wheels anymore.

      2. That’s fair on today’s tall trucks; I didn’t realize 33s were the new “small” tire. I just happened to know my 2007 Suburban is running 31-inch high KO2s. They seem to be more than sufficient and I do a decent amount of bad-roading – certainly more than most of these lifted mall crawlers will ever see.

  3. I hate myself for wanting one of these. The desire forms in the same limbic system that creates the urges for throwing rocks at things and lighting things on fire.

    1. I want one, I think they look awesome. That said, I’m not 20 anymore and I understand I’d look dumb, never use its potential and waste a ton of money my family could use for trips, school, investments etc….

      Double edged sword of growing up I guess.

  4. Lemme throw on my teal PFG fishing shirt, some wraparound Oakley’s and a fresh pair of New Balance’s. I’m taking the wife to Outback in my new Sierra AT4X.

  5. They could sell these things for $200k all day. The only thing that surprises me is that diesel 3/4 ton “off road” pickups weren’t on the market sooner. Since when do the Big 3 give up a chance to triple dip on profit margins?

      1. You’re right.

        Full luxury
        3/4 ton
        Pickup
        “Off road”
        All the towing capacity
        Diesel
        Family car

        They’re way more than triple dipping on the profit margins. Just like an everything bagel, except everything bagels are good.

  6. Look at that picture with the person in the GMC hat standing in the passenger door.

    The seat is about chest height. The door sill must be waist-height on this thing.

    This is not built for actual humans. They will be everywhere, and I hate it.

    1. “You know how their truck can fit a whole fourth-grade classroom below the driver’s sightline? Well ours can handle sixth-graders!”

      1. The kids are the worst, every time I pull up to a stop sign a local reporter has a dozen of them sneak out and sit down in a line in front of the truck

    2. “Huh, wonder why pedestrian deaths are rising? Eh, I gotta take a meeting with GM today. Is the Escalade out front yet?” -US politicians

    3. I hate it too. I’m 6’4″ and when they first released the Chevy/GMC monstrosities I couldn’t believe that the hood was chest height. At first I figured that I had seen one with a lift kit. Then I ran past a GMC dealership about a week later and saw 10 in a row at the same height.

  7. Those bedside steps are so tacky and cheap looking. And now Ford has copied them. I’d pay good money to delete them.

    Otherwise this is a good looking rig and the specs seem decent.

    1. Bed height is so high you need those things just access them from the side.
      I used to just reach over the side of my 1500 Silverado. Not any more. I need a step, even at 6’4″. Even WT models are hard to reach into. It’s too bad, but they do look cool all jacked up and I get it that most people only care about that.

      1. I’m 5′ 10″ and couldn’t reach into my ’97 2500 either. It’s not a new issue.

        But the things that bug other people (to the point of rage in some cases, not necessarily you) about vehicles are so different than the things that bug me that I guess I shouldn’t be surprised anymore.

        I don’t carry small things in my bed often enough to care about reaching in, that’s what a crew cab is for. In the rare cases that I do, I step on the tire or climb in the back; it isn’t that hard. On the other hand, I would have to look at that ugly step every single time I drive.

    2. They’re a simple and elegant solution to a problem that shouldn’t have existed in the first place. Next best thing would be to build the whole truck at least a foot, maybe in this trim as much as three feet lower.

        1. WE NEED TO COME UP WITH A WAY FOR PEOPLE TO ACTUALLY USE OUR BRO DOZERS!!!!

          …or what if we simply made vehicles that weren’t so comically massive that they require these sorts of solutions in the first place?

        2. old W/T trims for chevy used to be awsome for their low ride hight. Could still haul but you could almost sit on the side of the bed. Those were the days.

      1. A more elegant solution (other than more reasonable sized trucks) would be a fold down panel with the step. Flipped up, it could be body colored and blend with the rest of the bed. Fold down for the step. Hell, GM/Ford/Ram could motorize it on higher spec trims and charge an extra $1K for the $50 worth of parts.

  8. Coincidence that AT4X spells out ATTACKS? Yes, well-heeled truck buyers, this beast is a formidable foe for Whole Foods parking lots, boat ramps, and RV pull-throughs, not to mention squashing those girly-man Priusi and Miatae.

    1. Hey buddy, TGI Fridays is just around the corner to the left, there’s a whole world of parking lots for this thing to take up 2 spaces in

      1. Or, to awkwardly lurch halfway into one space, call it good, and leave it with the bed hanging out into the travel lane, because keeping track of those treacherous curbs on the passenger side is so, so, difficult, you know

        1. Or back into a space, bumping the rear wheels to the sidewalk and blocking the entire sidewalk with bed overhang and the trailer hitch extension needed to put the hitch down to a level usable for most trailers. It’s removable, of course, but the owner won’t bother and no one wants to risk getting shot because they took it off and put it into the bed.

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