BMW 3 Series Gran Turismo (2021) is 137 mm (5.39 inch) longer, 216 mm (8.50 inch) higher and has 367 liters (12.96 ft3) bigger cargo space than BMW i8 (2016).
BMW i8 (2016) is 113 mm (4.45 inch) wider and 20 kg (44 lbs) lighter than BMW 3 Series Gran Turismo (2021).