BMW 7 Series (2020) is 662 mm (26.06 inch) longer, 99 mm (3.90 inch) wider, 197 mm (7.76 inch) higher and has 331 liters (11.69 ft3) bigger cargo space than Porsche 718 Cayman (2021).
Porsche 718 Cayman (2021) is 564 kg (1,243 lbs) lighter than BMW 7 Series (2020).