GMC Sierra 3500HD (2015) is 936 mm (36.85 inch) longer, 168 mm (6.61 inch) wider and has 1504 liters (53.11 ft3) bigger cargo space than Mercedes G-Class (2016).
Mercedes G-Class (2016) is 3 mm (0.12 inch) higher and 108 kg (238 lbs) lighter than GMC Sierra 3500HD (2015).