BMW 5 Series Gran Turismo (2015) is 317 mm (12.48 inch) longer, 266 mm (10.47 inch) higher and has 346 liters (12.22 ft3) bigger cargo space than BMW i8 (2015).
BMW i8 (2015) is 42 mm (1.65 inch) wider and 570 kg (1,257 lbs) lighter than BMW 5 Series Gran Turismo (2015).