BoB and 100 octane fuel

[DuncanM]

I think the short answer is that every airfield where Fighter Command aircraft might land would have stocks of 100 octane fuel. Proving that they did is going to be tough, but it would have been a real nightmare for FC to have some airfields with 87 octane and some without, especially as landing at alternate airfields was very common, and strangely I've never read a single account of a Spitfire or Hurricane pilot having problems because he had to put 87 octane into his 100 octane modded aircraft.