BMW 3 Series (2015) is 170 kg (375 lbs) lighter than BMW 3 Series Gran Turismo (2018).
BMW 3 Series Gran Turismo (2018) is 200 mm (7.87 inch) longer, 18 mm (0.71 inch) wider, 79 mm (3.11 inch) higher and has 40 liters (1.41 ft3) bigger cargo space than BMW 3 Series (2015).