Kia Optima (2016) is 48 mm (1.89 inch) higher, 630 kg (1,389 lbs) lighter and has 20 liters (0.71 ft3) bigger cargo space than Mercedes CL-Class (2018).
Mercedes CL-Class (2018) is 240 mm (9.45 inch) longer and 12 mm (0.47 inch) wider than Kia Optima (2016).