Peugeot 408 (2014) is 372 mm (14.65 inch) longer, 20 mm (0.79 inch) wider, 195 mm (7.68 inch) higher and has 293 liters (10.35 ft3) bigger cargo space than Porsche Cayman (2014).
Porsche Cayman (2014) is 15 kg (33 lbs) lighter than Peugeot 408 (2014).