Kia Optima (2017) is 4 mm (0.16 inch) wider and 40 kg (88 lbs) lighter than Opel Insignia Sports Tourer (2014).
Opel Insignia Sports Tourer (2014) is 58 mm (2.28 inch) longer, 43 mm (1.69 inch) higher and has 50 liters (1.77 ft3) bigger cargo space than Kia Optima (2017).