Peugeot 508 (2014) is 452 mm (17.80 inch) longer, 28 mm (1.10 inch) wider, 194 mm (7.64 inch) higher and has 368 liters (13.00 ft3) bigger cargo space than Porsche Cayman (2016).
Porsche Cayman (2016) is 170 kg (375 lbs) lighter than Peugeot 508 (2014).