BMW 8 Series (G15) (2018) is 93 mm (3.66 inch) longer and 82 mm (3.23 inch) wider than Peugeot 408 (2020).
Peugeot 408 (2020) is 147 mm (5.79 inch) higher, 504 kg (1,111 lbs) lighter and has 35 liters (1.24 ft3) bigger cargo space than BMW 8 Series (G15) (2018).