GMC Sierra 2500HD (2017) is 836 mm (32.91 inch) longer, 158 mm (6.22 inch) wider, 256 mm (10.08 inch) higher and has 654 liters (23.10 ft3) bigger cargo space than Subaru Tribeca (2018).
Subaru Tribeca (2018) is 693 kg (1,528 lbs) lighter than GMC Sierra 2500HD (2017).
