Ford Flex (2014) is 221 mm (8.70 inch) wider and 675 kg (1,488 lbs) lighter than GMC Sierra 3500HD (2015).
GMC Sierra 3500HD (2015) is 575 mm (22.64 inch) longer, 225 mm (8.86 inch) higher and has 768 liters (27.12 ft3) bigger cargo space than Ford Flex (2014).