GMC Sierra 3500HD (2014) is 494 mm (19.45 inch) longer, 76 mm (2.99 inch) wider, 156 mm (6.14 inch) higher and has 1636 liters (57.77 ft3) bigger cargo space than Mercedes GLS-Class (2021).
Mercedes GLS-Class (2021) is 174 kg (384 lbs) lighter than GMC Sierra 3500HD (2014).