GMC’s 2020 Sierra AT4 HD looks so good, that it deserves its own live photo gallery. We got up and close and personal to Big Red’s new, off-road-focused beast at the 2019 Chicago Auto Show last month, and got some photos for your viewing pleasure.
The AT4 trim is an off-road focused equipment group. Its introduction on the 2020 Sierra HD joins two other GMC AT4 models – the 2019 Sierra 1500 AT4 and 2020 Acadia AT4. In the case of the new Sierra HD, the AT4 trim is based on the SLT model, slotting between the SLT and Denali trims. The AT4 HD will be available in either 2500HD or 3500HD models.
This particular unit is the Sierra 2500HD in Crew Cab, Standard Box body style coated in Summit White paint.
The exterior of the Sierra AT4 HD is defined by dark chrome exterior finishes and contemporary detailing. The bold grille is finished in black chrome and features a rugged texture set off by the AT4’s distinctive red vertical recovery hooks. A body-color front bumper rounds out the package.
The 2020 Sierra AT4 HD features full-LED lighting, with:
- High-intensity LED reflector headlamps
- LED turn signals
- LED Daytime Running Lamps (DRLs) with signature Daytime Running Lamps
- LED fog lamps
And check out those smoked amber roof marker lamps and new towing mirrors with a black cap.
The new Sierra AT4 Heavy Duty’s off-road capabilities are rooted in a unique suspension and supporting technologies that include:
- Off-road suspension
- Rancho Shocks
- Skid plates
- Eaton locking rear differential
- Traction Select System with specific Off-Road mode
- Hill Descent Control and Hill Start Assist
- Segment-exclusive 15-inch diagonal Head-Up Display with Off-Road Inclinometer
- HD Surround Vision for low-speed views of vehicle surroundings
The Sierra AT4 HD rides on 18-inch 6-spoke machined aluminum wheels with high gloss black accents as standard. A set of 20-inch, 6-spoke bright machined aluminum wheels with high gloss Black accents is available via the AT4 Premium Package, which the model seen here is equipped with. That package includes:
- AT4 Preferred Package:
- Universal Home Remote
- Rear sliding power window
- 8″ diagonal Premium GMC Infotainment with navigation
- Bose Premium Audio System
- Roof Marker Lamps
- Wireless Charging
- Driver Alert Package I:
- 20-inch machined aluminum with high gloss Black painted wheels
- 6″ Black rectangular assist steps (LPO)
The new BedStep, an integrated step located in front of the rear wheel openings that improves access to the cargo area, is present and accounted for on all 2020 Sierra HD models – including this Sierra AT4 HD. The door handles are body-color, and this angle provides a better look at the black rectangular assist steps.
GMC’s new MultiPro tailgate is standard on the Sierra AT4 HD. The GMC badge is proudly placed at the center of the tailgate, while the Sierra nameplate is placed below it. An AT4 badge is situated on the bottom end of the passenger-side of the tailgate. Interestingly, the rear end does not make any mention of the Heavy Duty nature of this pickup.
The taillamps are LED-based with GMC’s signature C-shaped lighting signature. The Cargo Area Lighting, located in the pickup bed, also uses LEDs. The rear bumper is finished in body-color, while featuring an improved CornerStep feature.
Inside, the Sierra AT4 HD features darkened trim specific to the model, including dark-tinted and textured aluminum finishes on the steering wheel, center stack and sill plates, as well as a unique Jet Black interior with Kalahari color accents in the seats and live stitching. Leather-appointed seating, with mini-perforated inserts and embroidered AT4 badging on the headrests, along with all-weather floor liners, is standard – simultaneously delivering durability and comfort.
The new Sierra HD is offered with two engine choices: GM’s all-new 6.6L V8 L8T gasoline motor making an SAE-certified 401 horsepower and 464 pound-feet of torque mated to GM’s 6L90 6-speed automatic transmission. The celebrated 6.6L V8 L5P turbo-diesel Duramax mated to a 10-speed “Allison” transmission making 445 horses and 910 pound-feet of torque is an extra-cost option. This 2020 Sierra AT4 HD features the optional Duramax mill.