Mercedes B-Class (2020) is 41 mm (1.61 inch) longer, 269 mm (10.59 inch) higher and has 243 liters (8.58 ft3) bigger cargo space than Porsche Cayman (2016).
Porsche Cayman (2016) is 4 mm (0.16 inch) wider and 220 kg (485 lbs) lighter than Mercedes B-Class (2020).