FIAT 500 (2017) is 455 kg (1,003 lbs) lighter than Mercedes B-Class (2014).
Mercedes B-Class (2014) is 843 mm (33.19 inch) longer, 159 mm (6.26 inch) wider, 69 mm (2.72 inch) higher and has 301 liters (10.63 ft3) bigger cargo space than FIAT 500 (2017).