Following last year’s enhancements, the Sierra HD is more sophisticated than ever. The infotainment system features Google Built-in and powers an available 13.4-inch display. The multiple cameras around the truck provide up to 14 different views, making life easier for drivers. Under the hood, the 6.6-litre gasoline V8 can be replaced by a 6.6-litre turbo-diesel V8 that impresses with 975 lb-ft of torque. No Sierra HD is more capable than the AT4X AEV model.