GMC Sierra 1500 (2015) is 626 mm (24.65 inch) longer, 236 mm (9.29 inch) wider, 135 mm (5.31 inch) higher and has 836 liters (29.52 ft3) bigger cargo space than Subaru Forester (2018).
Subaru Forester (2018) is 463 kg (1,021 lbs) lighter than GMC Sierra 1500 (2015).