Higher octane is better, have wondered about water injection as this is an octane modifier added 400bhp to a Vought Corsair.
Sometime in 1941 the Germans noticed that the Spitfire was suddenly hugely superior to the Me109 eventually one landed and was not destroyed and they found 101 octane in the tanks as opposed to the 75 octane then common, as there was no way the Germans could match this product then they went in fear thereafter.
So shoot down the other guy with higher octane petrol!
