GMC Sierra 3500HD (2015) is 1031 mm (40.59 inch) longer, 104 mm (4.09 inch) wider and has 1324 liters (46.76 ft3) bigger cargo space than Mercedes G-Class (2018).
Mercedes G-Class (2018) is 18 mm (0.71 inch) higher and 235 kg (518 lbs) lighter than GMC Sierra 3500HD (2015).