GMC Sierra 3500HD (2018) is 1407 mm (55.39 inch) longer, 255 mm (10.04 inch) wider, 544 mm (21.42 inch) higher and has 1650 liters (58.27 ft3) bigger cargo space than Mercedes A-Class (2017).
Mercedes A-Class (2017) is 1320 kg (2,910 lbs) lighter than GMC Sierra 3500HD (2018).