Kia Optima (2015) is 563 mm (22.17 inch) longer, 80 mm (3.15 inch) wider, 32 mm (1.26 inch) higher and has 169 liters (5.97 ft3) bigger cargo space than Mercedes A-Class (2017).
Mercedes A-Class (2017) is 150 kg (331 lbs) lighter than Kia Optima (2015).