BMW 3 Series Gran Turismo (2019) is 135 mm (5.31 inch) longer, 215 mm (8.46 inch) higher and has 366 liters (12.93 ft3) bigger cargo space than BMW i8 (2016).
BMW i8 (2016) is 114 mm (4.49 inch) wider and 175 kg (386 lbs) lighter than BMW 3 Series Gran Turismo (2019).