BMW 5 Series Gran Turismo (2018) is 272 mm (10.71 inch) longer, 111 kg (245 lbs) lighter and has 30 liters (1.06 ft3) bigger cargo space than BMW X4 (2015).
BMW X4 (2015) is 14 mm (0.55 inch) wider and 156 mm (6.14 inch) higher than BMW 5 Series Gran Turismo (2018).