BMW 8 Series (G14) (2018) is 63 mm (2.48 inch) wider than Mazda 6 (2016).
Mazda 6 (2016) is 21 mm (0.83 inch) longer, 111 mm (4.37 inch) higher, 453 kg (999 lbs) lighter and has 130 liters (4.59 ft3) bigger cargo space than BMW 8 Series (G14) (2018).