BMW 8 Series (G14) (2018) is 13 mm (0.51 inch) longer and 74 mm (2.91 inch) wider than Peugeot 508 (2017).
Peugeot 508 (2017) is 148 mm (5.83 inch) higher, 348 kg (767 lbs) lighter and has 180 liters (6.36 ft3) bigger cargo space than BMW 8 Series (G14) (2018).