BMW 3 Series Touring (2015) is 240 mm (9.45 inch) longer, 25 mm (0.98 inch) wider and has 9 liters (0.32 ft3) bigger cargo space than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 128 mm (5.04 inch) higher and 150 kg (331 lbs) lighter than BMW 3 Series Touring (2015).