BMW 3 Series Gran Turismo (2018) is 30 mm (1.18 inch) higher, 65 kg (143 lbs) lighter and has 5 liters (0.18 ft3) bigger cargo space than BMW 7 Series (2017).
BMW 7 Series (2017) is 274 mm (10.79 inch) longer and 74 mm (2.91 inch) wider than BMW 3 Series Gran Turismo (2018).