There is no "better" between them, they both have been designed to work best in the vehicle they are installed in.
Ladies and Gentleman... There is no substance. In my opinion Porsche is better because they make fast cars they can keep up with Ferrari. I think BMW can not keep up with Porsche. But BMW is a good car company too. It is way better than Mercedes Benz.
Porsche, BMW, Mercedes-Benz, Volkswagon, Audi, Bugatti, etc.
It can depend on which two you are comparing.BMW M1 V.S. Porsche 944.... BMW M1 would win.BMW M1 V.S. Porsche GT3.... Porsche GT3 would win.Porsche Cayenne (standard version) V.S. BMW M3 Comp Coupe... Comp Coupe would winCayenne V.S. x5.... Cayenne would win.
BMW Bentley Boxster (Porsche)
Audi, Porsche, Volkswagen, Mercedes, BMW
Porsche is better because of horsepower and lightweight.
Porsche
Volkswagen, Porsche, BMW, Mercedes, Ford, Opel.
Porsche, Audi, BMW, Mercedes-Benz, VW
Volkswagen, BMW, Audi, Porsche, Mercedes-Benz
BMW, Mercedes, Audi, Volkswagen, Porsche...