Alfa Romeo 4C (2018) is 7 mm (0.28 inch) wider and 417 kg (919 lbs) lighter than Kia Optima (2015).
Kia Optima (2015) is 867 mm (34.13 inch) longer, 279 mm (10.98 inch) higher and has 400 liters (14.13 ft3) bigger cargo space than Alfa Romeo 4C (2018).
