BMW 5 Series Gran Turismo (2016) is 612 mm (24.09 inch) longer, 100 mm (3.94 inch) wider, 264 mm (10.39 inch) higher and has 350 liters (12.36 ft3) bigger cargo space than Porsche 718 Cayman (2017).
Porsche 718 Cayman (2017) is 474 kg (1,045 lbs) lighter than BMW 5 Series Gran Turismo (2016).