GMC Sierra 3500HD (2017) is 844 mm (33.23 inch) longer, 175 mm (6.89 inch) wider, 512 mm (20.16 inch) higher and has 1481 liters (52.30 ft3) bigger cargo space than Kia Optima (2015).
Kia Optima (2015) is 1169 kg (2,577 lbs) lighter than GMC Sierra 3500HD (2017).