Ford Flex (2017) is 221 mm (8.70 inch) wider and 686 kg (1,512 lbs) lighter than GMC Sierra 3500HD (2017).
GMC Sierra 3500HD (2017) is 574 mm (22.60 inch) longer, 251 mm (9.88 inch) higher and has 768 liters (27.12 ft3) bigger cargo space than Ford Flex (2017).