It's not every week that we get to test a new vehicle under extreme conditions, but we gave this week's review truck a very thorough workout. We took a 2020 GMC Sierra 1500 AT4 on a 6,000-mile round trip adventure to the shore of the Arctic Ocean and back again as part of the 2020 Alcan 5000 Winter Rally.
Along the way, we subjected the GMC to hundreds of miles of unpaved roads, temperatures as low as 40 degrees below zero, and even slept in the truck one night when our planned motel was unexpectedly closed. As you might guess, the Sierra delivered us all the way to the north and then back to Portland safely.
We selected this particular Sierra because it was equipped with GM's new 3.0-liter Duramax turbo-diesel engine. This inline six-cylinder powerplant provides 460 pound-feet of torque, comparable to a big V8, while returning EPA-estimated 26 MPG on the highway.
Here in the tropical paradise around Portland, we actually saw up to 30 MPG. It probably won't apply in Oregon, but fuel economy declined across the board when temperatures dropped to 20 below zero. However, the Duramax still returned a healthy 18 MPG under those conditions. The standard plug-in block heater was also a much-needed feature.
The diesel Sierra comes with a 10-speed automatic transmission and the AT4 off-road package includes an advanced four-wheel-drive system. In addition to high and low-range 4WD gears, the Sierra includes an automatic mode that simulates the AWD performance of an SUV. This mode allows the truck to route power to any wheel with grip. On icy and snowy roads, and especially when conditions were changing rapidly, we found this mode delivered the best driving performance.
Inside, we appreciated the GMC's technology and luxury features. The heated seats and heated steering wheel were especially popular in the Arctic. GM's advanced safety and driver assistance features also came into play. We enjoyed the camera-based rear-view mirror because the camera is mounted high up on the back of the cab. This kept the lens clean and the view clear no matter how much ice and frost accumulated on the back window. The forward and side-facing cameras helped keep the GMC safe during cautious maneuvering.
Advanced driver assistance features like LED headlights, adaptive cruise control, head-up display, and blind spot monitors helped us drive safely through blizzards and through some very dark nighttime miles. On the ice and snow, we were thankful for anti-lock brakes as well.
Our test trip to the Arctic proved that GMC isn't exaggerating when they talk about their vehicles being professional grade. We took this Sierra to the most remote part of North America, and we'd choose it again for the same adventure.
2020 GMC Sierra 1500 AT4
Base price: $53,400
Price as tested: $66,295
Type: Full size pickup truck
Engine: 3.0-liter turbo-diesel (277 hp, 460 lbs-ft)
Transmission: 10-speed automatic
EPA estimated mileage: 22/26
Overall length: 231.7 inches
Curb weight: 4,950 pounds
Final assembly: Roanoke, Indiana
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