Kia Optima (2018) is 438 mm (17.24 inch) longer, 56 mm (2.20 inch) wider and has 89 liters (3.14 ft3) bigger cargo space than Mercedes GLA-Class (2014).
Mercedes GLA-Class (2014) is 24 mm (0.94 inch) higher and 165 kg (364 lbs) lighter than Kia Optima (2018).