BMW 3 Series Gran Turismo (2018) is 549 mm (21.61 inch) longer, 18 mm (0.71 inch) wider and has 161 liters (5.69 ft3) bigger cargo space than Citroen DS4 (2017).
Citroen DS4 (2017) is 18 mm (0.71 inch) higher and 297 kg (655 lbs) lighter than BMW 3 Series Gran Turismo (2018).