[ArtieBob]

The term PN was not in wide use in WWII, having really only been defined at the engineering level (I believe by the Ethyl Corporation) around 1943. PN ratings are normally expressed as a ratio ( i.e. 100/130 or lean/rich ratings for supercharged engines) In most US manuals I have seen from the late WWII era, neither the term Octane or PN was used, but rather the term "rating" followed by the "100/130" ratio format. I do not believe the Luftwaffe had a directly comparable system for rating fuels. Some intelligence documents do discuss the the relative performance and ratings of german to allied fuels in the later stages of WW II. If the war had continued using high performance supercharged piston engines, the US had tested Triptane fuel with PN 100/165
ArtieBob