Mercedes M-Class (2015) is 426 mm (16.77 inch) longer, 126 mm (4.96 inch) wider, 495 mm (19.49 inch) higher and has 528 liters (18.65 ft3) bigger cargo space than Porsche Cayman (2014).
Porsche Cayman (2014) is 745 kg (1,642 lbs) lighter than Mercedes M-Class (2015).