Speed graphs for Spitfire and Hurricane

[fruitbat]

Originally Posted by Kurfürst

. The Spit II I am afraid is correct, the type was limited to +9 lbs during the BoB, even with 100 octane

I am genuinely intrigued by this, and not messing around, on what is that based?

I've seen this obviously, dated july 1940



and as Crump has pointed out in the other thread that all Spit MkII's were using 100 octane fuel in June 1940.

So what have you got that proves they were only on 9Lbs boost during BoB?