With the Sierra's unveiling, we get more details about the powertrains available on the heavy duty GM trucks. The 6.6-liter turbocharged Duramax V8 makes 445 horsepower and 910 pound-feet of torque. That's the exact same output as the engine in the old models. But this time, the engine will be mated to an Allison-branded heavy duty version of the GM 10-speed transmission. A gas engine will also be available, but GMC hasn't revealed details on it yet.
The new Sierra boasts a range of new features, some that are unique to it, and some shared with the Silverado. A shared feature is the new steps in the bed sides that are standard on all Sierra HD models. Unique to the brand is the MultiPro tailgate with fancy drop-out step. This tailgate will be available on all trims, and it's standard starting with the mid-level SLT. There are some useful visibility features being shown on the new Sierra, too, such as an available trailer camera system with 15 possible viewpoints, and it can virtually show the rear view on the screen as if there wasn't a trailer in the way. GM's rear-view mirror screen also makes an appearance.
An AT4 off-road trim will be available on the new Sierra HD. It has slightly different styling with dark grilles and trim. Off-road upgrades include reworked springs and shocks, skid plates, standard all-terrain tires and a locking rear differential.
Pricing has not yet been announced, but the truck goes on sale this summer. Details on prices as well as further specifications will likely be announced near the on-sale date.