BMW 5 Series (2014) is 607 mm (23.90 inch) longer, 99 mm (3.90 inch) wider, 265 mm (10.43 inch) higher and has 289 liters (10.21 ft3) bigger cargo space than Porsche 718 Cayman (2017).
Porsche 718 Cayman (2017) is 359 kg (791 lbs) lighter than BMW 5 Series (2014).