GMC Sierra 2500HD (2014) is 851 mm (33.50 inch) longer, 155 mm (6.10 inch) wider, 249 mm (9.80 inch) higher and has 654 liters (23.10 ft3) bigger cargo space than Subaru Tribeca (2015).
Subaru Tribeca (2015) is 1007 kg (2,220 lbs) lighter than GMC Sierra 2500HD (2014).