Mercedes S-Class (2017) is 867 mm (34.13 inch) longer, 99 mm (3.90 inch) wider, 197 mm (7.76 inch) higher and has 338 liters (11.94 ft3) bigger cargo space than Porsche Cayman (2015).
Porsche Cayman (2015) is 740 kg (1,631 lbs) lighter than Mercedes S-Class (2017).