New for the 2019 model year, the Sierra AT4 package offers a bolder exterior paired to increased off-road capabilities compared to the base Sierra 1500. Clearly, a response to Ford’s recent success with their aggressive F-150 Raptor, the Sierra AT4 attempts to bridge the gap between the bland work truck and trail runner or rock crawler.
Duncan Aldred, VP of Global GMC, said, “The 2019 Sierra AT4 is designed for the customer who wants an elevated presence on the road and the capability to venture off life’s beaten path. It’s also the beginning for the AT4 brand, which will be seen on every vehicle in our lineup in the next two years.”
The sentiment that inspired the AT4’s introduction is clear, but in terms of overall capability, the truck offers a wide range of upgrades and innovative technology - though it may be tailored equally for the city slicker as much as for the truly rugged outdoorsman.
The 2019 Sierra AT4 adds a meaner look to the lineup of GMC’s all-new Sierra design. Aggressive haunches and contrasting red vertical tow hooks below the front headlights distinguish the AT4 from its stablemates from afar, while closer inspection reveals details like knurled texturing on grille fascias, fog lamp bezels, and extensive use of black chrome.
Additional touches include extensive AT4 badging, high gloss finish on window trim and mirror caps, and a C-shaped LED headlight setup. The entire look is designed to differentiate what ends up being a bolder vision from GMC than past offerings, and even bolder than similar trucks with less trail-ready capabilities.
The Sierra AT4’s high stance is not the result of a lift kit. Instead, GMC includes a factory installed 2-inch height increase complete with Rancho monotube shocks and skid plates to protect the truck’s underbelly.
The Sierra lineup offers superior cargo capacity when compared to its competition, and GMC is quick to point out that their five-foot truck bed even bests the cubic foot measurements of Ford and Ram’s 6.5-foot beds. Gear rails are optional to improve on the Sierra utility, while an industry-leading MultiProTM Tailgate allows for six different functions and positions including the ability to lower the gate and allow easier gear loading into the bed (especially helpful given the AT4 package’s increased ride height).
Standard AT4 wheels measure 18 inches and are finished in a dark metallic to match the rest of the AT4 design aesthetic. Knobby and capable Goodyear Wrangler Duratrac are standard. Optional 20-inch machine-faced wheels are available as an additional option.
Future AT4 models will even include an optional carbon fiber box in the rear, though GMC has not set a date for the upgrade’s release.
Under The Hood
GMC has crammed a variety of engine options under the Sierra AT4’s high, angular hood - standard equipment is a 5.3-liter V8 paired to an eight-speed automatic transmission with four-wheel drive and a two-speed transfer case. A locking rear differential and downhill assist (which uses antilock braking to smooth steeper descents) are also standard.
Other engine options include a 6.2-liter V8 or GMC’s all-new Duramax 3.0-liter turbocharged diesel inline six engine for improved efficiency and torque. Both upgraded engines also receive a ten-speed automatic trans and include engine stop/start technology as well as fuel management systems which allow for as few as one cylinder to run at a time.
The AT4 package also puts a Traction Select System into the driver’s hands, which adjusts transmission shift points and throttle mapping depending on the selection of preset drive modes to optimize performance in variable weather and terrain situations. For improved confidence when towing heavy loads, the AT4 features GMC’s ProGrade Trailering System and Trailering App.
Interior and Tech
Despite the Sierra AT4’s rugged appearance, GMC made a concerted effort to add premium touches to both the tactile surfaces and technological functions of the truck’s interior. Darkened trim and aluminum details come standard with the AT4 package, as do leather seats (with AT4 badged stitching) and rubber floor liners. The Sierra’s rear seatbacks can fold and open to reveal 10 liters of rectangular storage to complement a 24-liter space underneath the rear seats.
GMC’s head-up display projects a 3x7-inch, multicolored box of information onto the truck’s windshield that will include vehicle data such as an inclinometer measuring front-to-rear and side-to-side tilt and other key vehicle stats. The head-up display is customizable for added driver safety.
Surround Vision is an optional feature for the AT4 package that enables the center-mounted infotainment screen to show a bird’s eye view of the truck—useful in both tight city environs and when negotiating sharp turns during trail running and rock crawling.
Pricing and Buying
The Sierra in AT4 trim starts at $30,395 and will be available beginning in the Fall of 2018. However, not every piece of optional equipment will be available on the trucks that hit dealer lots first, so a short wait may be in order for more discerning customers.
GMC’s addition of an AT4 package to the Sierra lineup is clearly a result of recent market success from the impressively upgraded Ford’s F-150 Raptor. Every manufacturer is rushing to keep up with the market leader, including Toyota with the Tundra TRD Pro and Ram with the forthcoming Rebel (which will share an engine with the insane Challenger Hellcat).
An F-150 Raptor starts at just over $50,000, allowing the Sierra AT4’s to occupy a price point significantly lower than its current competition. However, consumers may find that its list of details and options don’t quite result in an overall package with quite the same level of off-road ability. In its niche, though, the AT4 is a distinctively designed offering that pairs slightly improved utility with a bolder style than GMC’s typical products.