Kia Optima (2018) is 91 mm (3.58 inch) longer, 1035 kg (2,282 lbs) lighter and has 23 liters (0.81 ft3) bigger cargo space than Mercedes G-Class (2016).
Mercedes G-Class (2016) is 7 mm (0.28 inch) wider and 484 mm (19.06 inch) higher than Kia Optima (2018).