Kia Optima (2017) is 1740 kg (3,836 lbs) lighter than Rolls-Royce Cullinan (2020).
Rolls-Royce Cullinan (2020) is 486 mm (19.13 inch) longer, 299 mm (11.77 inch) wider, 359 mm (14.13 inch) higher and has 50 liters (1.77 ft3) bigger cargo space than Kia Optima (2017).