GMC Sierra 3500HD (2016) is 360 mm (14.17 inch) longer, 115 mm (4.53 inch) wider, 132 mm (5.20 inch) higher and has 831 liters (29.35 ft3) bigger cargo space than Mercedes X-Class (2018).
Mercedes X-Class (2018) is 541 kg (1,193 lbs) lighter than GMC Sierra 3500HD (2016).