Kia Optima Sportswagon (2017) is 189 mm (7.44 inch) longer, 49 mm (1.93 inch) wider, 40 mm (1.57 inch) higher and has 49 liters (1.73 ft3) bigger cargo space than Lexus IS (2015).
Lexus IS (2015) is 60 kg (132 lbs) lighter than Kia Optima Sportswagon (2017).