GMC has completely redesigned its heavy-duty line of pickups this year. The brand has been in the truck business for over 100 years, and the 2020 GMC Sierra 2500 is the culmination of that extensive experience. “The all-new 2020 Sierra Heavy Duty is the most capable heavy-duty truck that we’ve ever offered,” says Duncan Aldred, vice president of Global GMC.
Part of the Sierra HD’s makeover is an all-new 6.6-liter V8 gas engine rated to produce 401 horsepower. It’s an impressive powerplant, mated to a smooth and time-tested six-speed automatic transmission. However, for this test, we ordered up a truck with the revised version of GMC’s proven Duramax 6.6-liter turbodiesel, which is now rated to produce 445 horsepower and 910 lb-ft of torque. It’s also paired with the brand’s new 10-speed automatic. With this combination, the GMC Sierra 2500 competes with diesel-powered versions of the Ford F-250, RAM 2500, and its mechanical twin, the Chevrolet Silverado 2500.