GMC Sierra 3500HD (2016) is 836 mm (32.91 inch) longer, 158 mm (6.22 inch) wider, 231 mm (9.09 inch) higher and has 927 liters (32.74 ft3) bigger cargo space than Subaru Tribeca (2018).
Subaru Tribeca (2018) is 788 kg (1,737 lbs) lighter than GMC Sierra 3500HD (2016).
