GMC Sierra 3500HD (2015) is 1075 mm (42.32 inch) longer, 257 mm (10.12 inch) wider, 496 mm (19.53 inch) higher and has 1643 liters (58.02 ft3) bigger cargo space than Subaru Impreza GT (2017).
Subaru Impreza GT (2017) is 1483 kg (3,269 lbs) lighter than GMC Sierra 3500HD (2015).