What It’s Like Driving The 2020 GMC Sierra HD AT4
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We recently shared with you how the 2020 GMC Sierra HD fares during heavy towing, and how a 2019 GMC Sierra AT4 Duramax performed during a rather grueling off-roading event up in Wyoming. But what about the 2020 GMC Sierra HD AT4? We took GMC’s latest dedicated off-road workhorse out on the open road and on rough terrain, and here’s what it’s like to drive it.
Before we head onto our impressions, let’s underline some interesting fun facts about GMC’s latest adventure machine. Since the AT4 variant has thus far proven successful on the standard 2019 GMC Sierra 1500 from a sales standpoint, it only makes sense that it be extended to the Sierra Heavy Duty pickups, right?
It’s an interesting niche that slots between a standard three-quarter / one-ton truck and a full-on dune-jumping machine like the Ford F-150 Raptor, which both Ram and Ford are also attempting to fill with the 2019 Ram Power Wagon and the 2020 Ford Super Duty Tremor.
GMC’s AT4 model adds just enough performance-enhancing components to take your heavy-duty truck off beaten paths without fear of damaging it. Among the enhancements are skid plates front and rear, tow hooks, Rancho Shocks, an Eaton rear locking differential and off-road specific tires. The Sierra HD AT4 also looks much meaner than a standard Sierra 2500HD or 3500HD thanks to a blacked-out grille and wheels.
But what interests us the most is that while the 2020 GMC Sierra HD AT4 can be powered by GM’s tried and proven 6.6L L8T V8 good for 401 horsepower and 464 pound-feet of torque, it can also be fitted with the 6.6L L5P V8 turbo-diesel Duramax engine which pumps out 445 horsepower and 910 pound-feet of torque, allowing the 2020 GMC Sierra HD AT4 to be the dedicated off-road pickup truck that boasts the highest towing rating in the segment.
We drove the Sierra HD AT4 both on and off the road. Just like the Denali model we drove to tow that giant trailer, we were pleased by the Duramax engine’s power delivery, smooth and free of unwanted turbo lag. The Allison-branded ten-speed automatic transmission was also a gem as it always seemed to find the proper gear and downshifted smoothly when applying throttle.
The Rancho Shocks suspension upgrade was also impeccably smooth, both on the road and on the bumpy stuff during our short off-road stunt. However, the off-road tires did lead to higher-than-average cabin noise. We were also disappointed by the rattles we heard from the truck’s cabin when things got bumpy.
Except for a Spartan interior with questionable build quality in some areas, we found the GMC Sierra HD AT4 to be a convincing package for anyone desiring off-road capability without losing any of the heavy-duty benefits.
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Do you do ANY research before writing an article and claiming to be in the know? These don’t have a lift of any sort, tires are the same as ANY 20″ tire is on a 2020 HD, and the new gas V8 isn’t tried and true. The AT4 is the same as a regular old Z71 when in the HD trucks. Please don’t hype something that isn’t true, as it’s even worse if you’re an advocate of the brand. Misinformation makes you look like a fanboy, or like an ad for GMC.
I agree
Agreed
I feel like the quality of the GMA articles recently have gone downhill quite a bit.
Maxxer,
Apparently you need to read before posting. The article makes no mention of the AT4 HD having a lift.
That is on the half ton trucks.
I think the writer was confused or assumed the 2500HD AT4 came with a 2″ lift like the 1500 AT4.
These 2500HD and 3500HD are workhorses truck, and GM doesnt even offer center console storage on lower trims, theres no space for anything on these trucks.
I wish they would stick the electronics someplace else and allowed no center console storage on upper trim levels to give me the space in the cabin that the overall truck size should promise. Besides, my girlfriend does not like to sit on a filing cabinet.
Ford and RAM offer it and have for years. I’m pretty sure the previous gen did as well.
GM is also missing adjustable seat belts and a DIC that can be controlled from the steering wheel. Something that I’m positive Ford has had since at least 2014 in even the base trucks.
All 3 of you have no idea what you are talking about lol. Please do some better research before commenting
You due some research, both the WT and Custom doesnt have center console storage in neither up/down. In order to get storage with the bench seats need to get the LT model with the convenience package.
In my opinion GM should have offer it no matter what trim you choose. They missed this one.
Every two years I buy the highest trim GM HD I can find that has a bench seat, no center console. The electronics on the highest levels is built into the thing, that is why the packages force one to get it. I have even looked into getting a custom shop to move the equipment and replace the bucket seats with the bench. If you have some research that says I can get the bench seat in a trim with all the other fixings, please let me know
The cheapskate version of nearly every pickup on the market doesn’t include a center console. They used to only have bench seats.
If it’s that important, perhaps a used model with a higher trim level is a better budget fit. Or you can get a deal on a new Ford and just plan to replace it after it’s completely shot in 5-6 years.
All the base models from GM, Ford, and Ram have 40/20/40 split bench seats. What people are referring to is the fact that the flip up center console in the GM models no longer have storage underneath them, unlike the competitors trucks. In the case of the Silverado HD’s, you have to step up to the LT trim level to get a 40/20/40 split bench with underseat storage. Whereas Ford offers it on the XL packaged Superduty and Ram offers it on the Tradesmen packaged 2500/3500’s.
Aside from the mirrors. This thing is purty.
The 6.6 engine is brand new, not “tried and true” Where do you get these writers?