GMC Sierra 2500HD (2015) is 1458 mm (57.40 inch) longer, 267 mm (10.51 inch) wider, 533 mm (20.98 inch) higher and has 1379 liters (48.70 ft3) bigger cargo space than Subaru Impreza GT (2017).
Subaru Impreza GT (2017) is 369 kg (814 lbs) lighter than GMC Sierra 2500HD (2015).