Just last week, GM Authority exclusively reported that General Motors was considering development of a new GMC Sierra HD AT4X model designed to slot in above the “regular” GMC Sierra HD AT4. Now, we have the first images of what could be the upcoming 2023 GMC Sierra HD AT4X off-roader testing in public.
As reported last week, GM is actively looking at a variety of upgrades that take the GMC Sierra HD AT4 to a whole new level of off-road capability, thus giving rise to a new AT4X HD variant. Engineers have reportedly been busy testing a number of suspension configurations, including numerous shock options, such as swapping between upgraded versions of the “standard” Sierra HD AT4’s Rancho shocks and more robust versions of the Dynamic Suspension Spool Valve (DSSV) shock technology currently found on the light-duty GMC Sierra AT4X and its corporate cousin, the Chevy Silverado ZR2.
Now, with the appearance of this new prototype model, it looks as though the program which GM Authority first reported on has advanced from internal evaluation to real-road testing – a significant step in GM’s testing protocols, to be sure.
Additionally, this new prototype model looks to be equipped with a number of features that remain consistent with the range-topping off-road models in GM’s midsize and full-size pickup lines, as well as features that take it a step above GMC’s current Sierra AT4 HD trucks. These features include a stripped-down front bumper with enhanced ground clearance, as well as a highly visible, beefed-up front skid plate, a combo that underlines the GMC Sierra HD AT4X as laser-focused on off-roading with the removal of any unnecessary low-hanging bits, such as chin spoilers or diffusers. The improved ground clearance and approach angle will certainly help off-road.
This 2023 GMC Sierra HD AT4X prototype is also running Goodyear Wrangler Territory MT tires, which are consistent with the other products in GM’s ZR2/AT4X lineup. Although it looks like an attempt has been made to obscure the sidewall lettering, it isn’t too difficult to confirm the tire type and brand in use here.
By comparison, the current Sierra HD AT4 is fitted with either Goodyear Wrangler TrailRunner A/Ts, or Goodyear Wrangler Duratrac tires. To note, Territory MT tires can also be found on the recently released Chevy Silverado ZR2, as well as next-gen Chevy Colorado ZR2 and GMC Canyon AT4X prototypes.
Speaking of the running gear, this 2023 GMC Sierra HD AT4X is running camouflaged wheels, which are similar to the camo-clad wheels used for the light duty GMC Sierra AT4X and Chevy Silverado ZR2 prototypes seen previously. It’s also worth noting the eight-lug design for the wheels used with this heavy-duty prototype model.
One of the most critical upgrades for the new Sierra HD AT4X will be the suspension, and although it’s difficult to tell, the shocks on this prototype appear to differ from the red-tubed Rancho shocks equipped by the current GMC Sierra HD AT4. By contrast, these shocks may be similar to the Multimatic DSSV units in use with the rest of the AT4X and ZR2 lines.
Although DSSV shocks are not typically stout enough to handle the heavy-duty GMC Sierra, GM Authority has confirmed that DSSV shocks may be part of GM’s testing for the new Sierra HD AT4X, possibly giving up the usual HD capability in favor of enhanced off-roading. It’s also possible Multimatic will offer a new HD-spec DSSV shock that could bridge the gap.
Keep it locked on GM Authority for all the latest with regard to the new 2023 GMC Sierra HD AT4X, and make sure to subscribe to GM Authority for more GMC Sierra news, GMC news, and around-the-clock GM news coverage.
2023 GMC Sierra HD AT4X Photos Click to contract
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View Comments
I see some real potential here, can’t wait to see it debut!
Paired with an 8L OHV gasser
No, I’d get it in a Duramax turbo diesel!
Nah, duramax weighs 900lbs more. A return of the 8.1L gas V8 would be an epic engine with plenty of torque
As someone who has owned an 8.1 in the past it would definitely be an awesome engine. That said unless they completely redesign it for our current emissions it will just be a memory. It's been stated that both the gas and diesel powertrains will be updated, but I assumed that meant the 6.6 gas engine. I heard rumors several years ago about a possible bigger engine but nothing recent, have you heard recent rumors?
GM Authority reported on it 2 years ago. It's possible its been shelved but the Ford 7.3 OHV has been a hit
It will be interesting to see if they ever follow through with it. I currently drive a Duramax,but if they were to introduce a modern 8.1 I would give it a serious look if the numbers were appealing enough. Diesels are king when it comes to pulling but with skyrocketing prices I think more and more people will be priced out of diesel ownership.
If its only offered with a gasser then it would be competing against the Power Wagon. Which I'd argue is the superior setup because of the disconnecting sway bars and front solid axle. Yes the DSSVs are a much more capable shock than the fairly basic Bilsteins that come stock on a Power Wagon. But lets be real... if you can afford this truck, which based on the AT4X 1500 pricing would be probably at least $80K, then you can afford to have a Carli or Thuren suspension setup with custom King or Fox shocks.
However if they offered it with the Duramax then it would be a totally unique truck in the market. The combo of diesel engine, front + rear locking diffs, and high performance shocks from factory would be a killer truck that Ford and Ram currently don't offer.
The articulation the Power Wagon is able to achieve with the sway bar disconnected, is completely unique among HDs. It's crazy how crossed up it can be, and still keep pulling with all four. But all that flex, does result in onboard payload being reduce to half ton levels.
It really is a truck optimized for pulling heavy-ish bumper trailers further into the bush, and back, than any other pickups. All that HD weight, all that articulation and three lockers, makes it a bumper puller extraordinaire in the rough stuff. But at other HD tasks, it is a bit limited.
But will the 8.1L be efficient?? 🇷🇺🇷🇺🇷🇺🇷🇺
💪🇷🇺🇷🇺🇷🇺💪
The original 8.1 was a Chevy big block… not even a contemporary of the LS’s that were being produced along side of it. Even then with the Alison 5 speed it was proved to be very “efficient” 😆😆😆 for it’s day. Way more than the fod V10 or dodge magnum. An 8.1 gen 5 V8 wouldn’t guzzle gas per se.
That said I’m disappointed that the 6.6 didn’t get the 10 speed or skip fire tech. I understand the marketing of tried and true tech, but the 10 speed is way more efficient as is keeping pumping losses at a minimum for an even larger V8. Also, rebuilding 5.3’s with AFM, it’s noticed that the rings on the deactivated cylinders are often like new while the always on cylinders exhibit normal wear. Slip fire would help ring life even more by spreading the love around.
The 6.6 is showing 16-17 mpg highway anecdotally on forums, 14 combined. If they added the 10 speed and DSF, you would probably see 19-20 highway with 16 combined. An 8.1 would see 18-19/15 if similarly equipped, and as an AT4X 15-16/14
Curious to find out more solid details about this truck. One thing I noticed is the fender flare extensions/ flaps that extend below the body line appear to be shorter on this particular truck. That's a good thing IMO, I honestly wish the forward facing flap on the rear would disappear all together. I removed the forward flap on my '15 but it's integrated into the flare design on the current trucks. The front of this test mule is running no flaps, but I assume they will be present on the production model.
I'm excited about the AT4X HD, it may be the truck that finally gets me out of my '15. The giant price tag however is going to be a bit of a buzzkill!
Do you really need a 8.1 litre V8 to drive to Dunkin Donuts for your daily fix ?
What about the 505 hp Duramax?
https://gmauthority.com/blog/2021/09/2023-silverado-hd-sierra-hd-duramax-rumored-at-nearly-1100-pound-feet-of-torque/
But will it have the new interior?
The refreshed AT4X HD will have the new interior. I think it's safe to assume the HD line will follow the 1500 formula. That would mean the Pro (base work truck) has the old interior, SLE, Elevation, and SLT all get a version of the refreshed Silverado dash, and the AT4 and Denali lines get the refreshed GMC exclusive dash.
Only question is release date. Will they be released this fall as a '23, or will they be released mid-year as a '23.5?
Yes, here is the new interior:
https://gmauthority.com/blog/2022/03/refreshed-2024-gmc-sierra-hd-interior-spied-for-the-very-first-time/