I have read somewhere that the Jugoslav airforce once replaced a Rolls Royce engine with a Daimler Benz and that the performance of the Hurricane was improved. If that is true, I wonder if the same result would have occurred had a DB engine been substituted for an RR in a Spitfire? If that would be so, woulld it logically follow that DB engined 109's would out perform Spitfires I and II?