GMC Sierra 2500HD (2017) is 360 mm (14.17 inch) longer, 115 mm (4.53 inch) wider, 157 mm (6.18 inch) higher and has 558 liters (19.71 ft3) bigger cargo space than Mercedes X-Class (2018).
Mercedes X-Class (2018) is 446 kg (983 lbs) lighter than GMC Sierra 2500HD (2017).