Audi A4 Avant (2018) is 93 mm (3.66 inch) higher, 374 kg (825 lbs) lighter and has 85 liters (3.00 ft3) bigger cargo space than BMW 8 Series (G15) (2018).
BMW 8 Series (G15) (2018) is 105 mm (4.13 inch) longer and 60 mm (2.36 inch) wider than Audi A4 Avant (2018).