BMW 5 Series (2016) is 488 mm (19.21 inch) longer, 63 mm (2.48 inch) wider and has 155 liters (5.47 ft3) bigger cargo space than Mercedes B-Class (2020).
Mercedes B-Class (2020) is 99 mm (3.90 inch) higher and 215 kg (474 lbs) lighter than BMW 5 Series (2016).