BMW 3 Series Gran Turismo (2019) is 126 mm (4.96 inch) longer, 125 mm (4.92 inch) higher and has 75 liters (2.65 ft3) bigger cargo space than BMW 4 Series (2016).
BMW 4 Series (2016) is 42 mm (1.65 inch) wider and 150 kg (331 lbs) lighter than BMW 3 Series Gran Turismo (2019).