BMW 5 Series Touring (2018) is 151 mm (5.94 inch) longer, 35 mm (1.38 inch) wider, 95 mm (3.74 inch) higher and has 60 liters (2.12 ft3) bigger cargo space than Kia Optima (2018).
Kia Optima (2018) is 341 kg (752 lbs) lighter than BMW 5 Series Touring (2018).