BMW 8 Series (G14) (2020) is 455 mm (17.91 inch) longer, 102 mm (4.02 inch) wider, 44 mm (1.73 inch) higher and has 200 liters (7.06 ft3) bigger cargo space than Porsche 718 Cayman (2014).
Porsche 718 Cayman (2014) is 492 kg (1,085 lbs) lighter than BMW 8 Series (G14) (2020).