Buick Regal TourX (2020) is 131 mm (5.16 inch) longer, 2 mm (0.08 inch) wider, 13 mm (0.51 inch) higher and has 90 liters (3.18 ft3) bigger cargo space than Kia Optima (2019).
Kia Optima (2019) is 122 kg (269 lbs) lighter than Buick Regal TourX (2020).
