BMW 3 Series Gran Turismo (2021) is 168 mm (6.61 inch) higher, 344 kg (758 lbs) lighter and has 101 liters (3.57 ft3) bigger cargo space than BMW 8 Series (G15) (2018).
BMW 8 Series (G15) (2018) is 17 mm (0.67 inch) longer and 73 mm (2.87 inch) wider than BMW 3 Series Gran Turismo (2021).