Road Test Review – 2020 GMC Sierra 2500 HD AT4 – By Carl Malek

It’s hard to deny the love affair that buyers have developed for rugged light duty trucks like the dune slaying Ford Raptor, the Ram Rebel 1500, as well as the Chevrolet Silverado Trailboss. With these models becoming key cogs for their respective brands in terms of sales, it only seems natural to extend this magic to their heavy duty counterparts. The Ram Power Wagon, The Ford Super Duty Tremor, and the Nissan Titan XD Pro 4-X were the early shots into this endeavor and naturally GMC had to issue a rebuttal of their own with the Sierra HD AT4. But can the AT4 magic work seamlessly in a bigger and more work focused package?


Back In Black And Boldly In Charge:

When our jet black 2500 grade HD tester arrived at the office, its sheer size was arguably the first thing that immediately drew stares. This is a truck that is big, mean, and is eager to flaunt its size. With 22 feet of truck to work with, GMC designers did a great job with making the canvas work. The big front fascia is highly expressive thanks to bigger LED infused headlights, a massive front grille, and even a complimenting (and functional) hood scoop. AT4 models like our rig also benefit from several package exclusive touches including bright red front tow hooks, meaty off-road tires that are wrapped around a set of stylish wheels, as well as dark accents that are scattered throughout the truck.

The side profile is functional and practical, with the Sierra adopting the same bed side mounted steps that also see duty in its light duty cousin. The rear of the Sierra is arguably where the design does stumble a bit. We like the darkened taillamps as well as the handy rear bumper mounted steps, but when compared to offerings from Ram and Ford, we think that the GMC comes up just a bit short in this arena. Our tester also came equipped with GM’s all new MultiPro tailgate system. The idea here is to offer a tailgate that can adapt to a wide variety of roles and we like the effort GMC put in to try and make this trick party piece work. We liked the extra bed step that can emerge into place, as well as the ability to open the top half of the tailgate to help accommodate longer items. However, the multiple steps that come with accessing each of its tricks felt like doing a very complex jigsaw puzzle, and it took us a couple of tries before we formally memorized all the steps needed to use it correctly. Also, lowering and raising some of the components does require a bit of muscle, and it can get tiring after a few uses.


Posh Interior Comes Just Short Of A Perfect Game:

As for the interior, GMC designers were keen to take full advantage of the HD’s size, and have crafted a very pleasurable place to spend time in. Occupants are greeted with a massive 8.0 inch touchscreen infotainment system that has crisp graphics, and a simple interface that has minimal lag time between inputs. The black leather seats have a nice finish, and feel great once your nestled into place with soft touch plastics being used on many key touch points. However, there is also noticeable pieces of cheap hard plastic scattered in other areas, and the faux chrome trim that surrounds the unit is reminiscent of the materials used in the more mas market oriented Silverado. This is especially glaring since the AT4 crosses the $70,000 barrier, and that puts it firmly in the crosshairs of rivals from Ford and Ram which offer better interior quality.

But while an extra trip to the school of refinement is needed for the materials themselves, the sheer amount of space here deserves high marks. There is abundant front leg room for passengers, with equally ample amounts of shoulder and arm room. Our test rig came equipped with a crew cab, and rear passengers also get to indulge in limousine-esque levels of space when they are being shuttled about in the truck with the rear bench offering 39.9 inches of headroom and 43.4 inches of legroom. When they are not present, the massive area can be used to enhance storage, with the truck easily swallowing several big loads of groceries, as well as swallowing an equally large load of recyclables for our trip to the bottle return machine. Front occupants get a massive center storage console, a cave like glovebox, and plenty of cupholders to store drinks of all shapes and sizes. The AT4 also tries its best to be a mobile office, with our tester having several USB ports, two 12-Volt outlets for charging phones, wireless charging pad, and even onboard WiFi. The bed also comes equipped with an extra 12-volt outlet for running equipment outside the truck which should be a valuable tool for contractors. The cabin does a decent job drowning out wind noise, but the larger off-road tires and optional diesel engine still manages to make things a bit loud when commuting through town.


Slaying Trails And Taking Names:

The core purpose of the AT4 trim is its ability to bring high levels of ruggedness and capability to pickup buyers. A 6.6 liter gasoline engine is the base offering, but buyers looking for more towing power and fuel economy can step up to the optional 6.6 liter Duramax turbodiesel V8 which powered our truck. The optional engine dings your wallet for $9,980 but it is worth the cost thanks to the 910 lb-ft of torque which allows the twin-turbocharged V8 to move the 6,950 lb truck with relative ease. Stepping up to the diesel also allows you to take full advantage of the new 10-speed Allison automatic transmission ( the gasoline model can only be had with an older six-speed.) The new transmission delivered crisp gear changes during our time with it, and we didn’t catch it sleeping on the job either. We didn’t do any towing during our test period, but buyers can take comfort knowing that the 2500 HD AT4 can tow up to 18,500 lbs and haul just over 3,597 lbs.

We made up for it though by sending the truck through some of the off-road trails and rough backroads that define our challenging off-road test route to see if the AT4 package can indeed live up to its claims. The AT4 managed to pass everything with flying colors, and we came away impressed with just how solid of a ride our tester delivered in the roughest of muck. On-road behavior on the other hand is about what you would expect for a potent off-roader with very light steering that delivers little to no road feel to the driver. The high driving position further enhances this disconnect, and it can feel like your driving a pint-sized tractor trailer at times. Visibility is good, and like other GM products, the rearview camera mirror helped improve rear visibility and it compensated for the thick rear pillars. The backup camera itself also has a number of tricks including an all new 360 degree mode that allows you to see what the truck sees from all angles when backing up or entering a parking space.


Value Quotient:

With all the off-road equipment and other goodies that the AT4 brings to the table, it should come as no surprise that a sizable premium comes with the price of purchase. Base AT4 models start at $59,295 with diesel equipped variants having a loftier $69,185 base sticker. Our tester arrived with over $18,000 of optional extras which helped push the final price to $77,155. This figure would have been higher ($77,905) but a $250 AT4 Premium Package discount helped push the price down slightly. This is a noticeable increase over the $37,195 seen in base 2500 HDs, and the Sierra is still the priciest HD offering of the bunch. For comparison, equivalent rivals like the Ford F-250 Tremor, ($53,390) Ram Power Wagon, ($53,450) and even the Nissan Titan XD Pro-4X ($53,980) all undercut the base AT4 in price and some of them even offer more standard equipment and technology. As such, long term value here is not as good, though we suspect that will not stop brand loyalists and even some new buyers from taking the plunge.


This problem with long term value is a shame, since the GMC Sierra 2500 HD AT4 has a lot of tools that help it be a formidable force in the heavy duty pickup segment. The MultiPro tailgate (while far from perfect) is a very clever idea, and we like some of the off-road equipment that comes bundled into the AT4 experience. Hopefully, some changes in pricing as well as a mid-cycle update to address some of its interior flaws can help the Sierra gain back some ground especially as the pickup segment as a whole continues to be a key battleground for many automakers.