BMW 3 Series Gran Turismo (2014) is 431 mm (16.97 inch) longer, 42 mm (1.65 inch) wider and has 34 liters (1.20 ft3) bigger cargo space than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 49 mm (1.93 inch) higher and 340 kg (750 lbs) lighter than BMW 3 Series Gran Turismo (2014).