In Pictures: 2020 GMC Sierra 2500HD Denali & AT4 | First Drive

Three-quarter ton pickups are setting a new course

Editor’s Note: Full gallery at the end of this post.

Jackson Hole, WY – Heavy-duty trucks continue their upward trend, marking off more and more boxes within this fairly expensive category. For GMC fans and shoppers, this means a Denali version of the 2500HD – the only luxury heavy-duty pickup in its class.

Plus, the introduction of the rugged yet sleek AT4 trim flossing a darker look with enhanced off-road performance. 

Redesigned for 2020, GMC’s three-quarter ton pickup is a major departure from the outgoing model. From styling and new interiors to significantly improved performance and towing capabilities.

Below, we take a closer first look at both trims – the 2500HD Denali and 2500HD AT4. Two models that will likely outsell the entry-level SLT.

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The new pickups go on sale late 2019, available in 2500HD and 3500HD models, either dual rear wheel or single rear wheel configurations. 

1) Sierra 2500HD Denali: first luxury heavy-duty pickup on the market

2020 GMC Sierra 2500HD Denali
The luxury Denali trim is a top-seller with the smaller Sierra 1500 pickup but adding the luxury trim to the heavy-duty 2500 was a smart, long overdue move by GMC. Photo: Amee Reehal

Think of big, burly heavy-duty trucks and remote oilfields and agriculture likely come to mind. But premium HD pickups with luxury appointments? Not so much.   

However, GMC is looking to change this – or more accurately, have recognized the market – with the first premium heavy-duty truck in the segment with the new Sierra HD lineup which ramps up power, intelligence and segment advancements for 2020. 

Also read: 6 New Things About the 2020 Sierra 1500

If you think about it, this all makes sense: blending uncompromising capabilities for those who require it, with posh interiors including the latest in tech and convenience. And why not? Big truck shoppers spending north of $80,000 should have the latest in premium features – under the hood, in the cabin, and on the styling front.

Considering over 50-percent of Sierra HD buyers go for the Denali, GMC clearly wasn’t going to compromise anything with this range-topping, best-selling model. 

New Denali Interior:

2020 GMC Sierra 2500HD Denali interior
Inside, the 2020 Sierra 2500HD Denali looks to redefine what we’re familiar with then it comes to heavy-duty truck cabins. Photo: Amee Reehal
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Denali cabins have always been next-level with trim-exclusive materials – the 2020 HD is no exception. Expect dark-finish aluminum decor, open-pore wood trim, and premium leather-appointed seating inside. 

The overall layout is good. For front storage, you’ll find a pair of glove boxes which is common with HD trucks, with a small storage spot above the touchscreen which won’t hold a lot (maybe a phone, if that’s where you put it); the centre storage between the seats is massive and the cover also sports a small cavity to hold small things, but again, likely for the good old mobile phone. 

The control layout is functional and logically setup. Directly below the screen are two large dials/button with four buttons in between to control track forward/back and a home button.

Below this is the temperature and HVAC controls which take up a fair bit of real estate. Two large buttons/dials for driver and passenger temp controls flanking all the individual climate settings.

2) Sierra 2500HD AT4: three-quarter-ton truck for adventurers and off-roading

2020 GMC Sierra 2500HD AT4
Bolder looks with a healthy dose of black features, the the Sierra 2500HD AT4 offers heavy-duty truck buyers a great option for off-roading and adventure-seeking. Photo: Amee Reehal

Despite the Denali’s popularity with GMC truck buyers, we wouldn’t be surprised if the AT4 resonates even more in the coming years. Less upscale with those luxury touches, the Sierra AT4 HD takes on a more sporty personality with a strong focus on off-road capability. It’s a new trim in the Sierra HD family (or more specifically, replacing the old All-Terrain trim), rounding out the lineup nicely offering more badass styling with added performance. And, frankly, just looks awesome all around. 

Exterior: Athletic looks and capability

On the outside, the AT4 HD finds touches of dark chrome exterior finishes and contemporary detailing. Both the front and rear bumpers, along with the grille surround, get body coloured treatment for a sharper look which really sets this grade apart.  

Instantly, you’ll know this hauler is an AT4 with those huge, red vertical recovery hooks up front, sitting below a new bold grille with a rugged texture and finished in black chrome. 

2020 GMC Sierra 2500HD AT4 exterior
AT4 kicking up some dirt riding on 18-inch wheels standard with 20-inch optional. Photo: Amee Reehal

AT4 HD Interior: stealtier personality

The stealthy, sporty look continues inside the AT4 HD model with darkened trim including dark-tinted and textured aluminum finishes on the steering wheel, centre stack and sill plates.

The seats find leather appointments with mini-perforated inserts and embroidered AT4 badging on the headrests. For added durability, GMC throws in all-weather floor liners as standard, also with AT4 badging. 

Tech includes the 15-inch diagonal Head-Up Display with Off-Road Inclinometer, and the HD Surround Vision feature handy for those low-speed views of vehicle surroundings.

Performance: off-road upgrades for serious adventurers

Again, it’s not just looks. GMC backs up the rugged esthetic touches with performance to match including an off-road suspension you won’t find on the other Sierra HDs. 

2020 GMC Sierra 2500HD AT4 performance
The AT4’s traction system includes a model-specific Off-Road mode; Hill Descent Control and Hill Start Assist are also in the mix, as standard. Photo: Amee Reehal

Paired to Rancho Shocks, skid plates, and an Eaton locking rear differential, this is type of heavy-duty pickup real adventurers will appreciate; those taking their trucks to new heights, (yes, literally). Traversing moutains to secure some untravelled hiking trails, or maybe hauling a pair of dirt bikes to undiscovered regions. That sort of thing. 

This beast rides on 18-inch wheels standard with 20-inch optional; both sizes wrapped with all-terrain tires by Michelin. The AT4’s traction system includes a model-specific Off-Road mode; Hill Descent Control and Hill Start Assist are also in the mix, as standard. 

Takeaway: Should you buy a 2020 Sierra HD?

The ‘mundane work truck’ stigma is slowing disappearing for heavy-duty trucks. Considering most HD pickup owners are actually towing their nice toys and not necessarily hauling hay or pulling massive production equipment in the oilfield, should tell you something. 

Also See: Truck Reviews

The new 2020 Sierra HD has really taken on a new personality for these everyday truck drivers who demand more. Towing nearly 36,000 pounds, adding a stylish AT4 to the lineup, offering a new 10-speed automatic transmission, and completely revamping the tailgate with more features are just a few examples of how GMC is redefining the popular Sierra Heavy-Duty. 

But competitors like Ford are on the same page, recently unveiling their new 2020 Super Duty making 1050 lb.ft or torque and now technically surpassing the Sierra HD in the towing department with 37,000 pounds. But hey, what’s an extra 500 pounds. 

Learn more: GMC Sierra HD (US) | GMC Sierra HD (Canada)

Photos of the new 2020 Sierra 2500HD – AT4 and Denali models

Amee Reehal
Shooting cars professionally since film was a thing, Amee's work has appeared in various outlets including NBC Sports, Chicago Tribune, SuperStreet, GlobeDrive, MotorTrend, and others. He's the managing editor & founder of Find him travelling, spending time with his kids and family. Or golfing, poorly.