The new Sierra HD's exterior is more visually distinguished from the Sierra 1500.
Aside from its roof, which is shared with the light-duty Sierra, all other visible elements are unique to the work-focused HD truck.
The standard engine is a 401-hp, 6.6-liter V8 with a six-speed transmission.
A 445-hp, 6.6-liter turbodiesel V8 engine with a 10-speed transmission is also available.
The new truck is 10 inches longer than the previous one, which translates to more legroom.
GM claims that the new HD, when properly equipped, can tow up to 35,500 pounds.
Available active safety features include FCW, AEB, BSW, and rear cross traffic warning.