Context, timeline...lol, sure no problem, we'll start with these:
Emergency +12 lbs./sq. in. Boost Operation: Pilot's Notes, Merlin II, III and IV, 4th Edition, April 1940, page 6.
These documents relating to fuel requirments of the the Advanced Air Stiking Force and the Air Component, both in France during May 1940, give some idea of consumption, stocks, and how fuel requirements were calculated. As can be seen the Hurricanes used 100 octane, the Blenheim used a mix, while the Battle and Lysander used 87 octane, as did any transport, liason, visiting types etc.
To underscore the above documentation of Hurricanes using 100 octane fuel in France please note the following:
S/L J. O. W. Oliver, 85 Squadron, 10 May 1940
P/O John Bushell, 151 Squadron, 18 May 1940
S/L E. M. Donaldon, 151 Sqdn., 18 May 1940
F/O Paul Richey, 1 Squadron, 11 May 1940
F/O E. J. Kain, 73 Squadron, 14 May 1940
P/O D. W. A. Stones, 79 Squadron, 14 May 1940
Sgt. R. C. Wilkinson, 3 Squadron, 14 may 1940
P/O R. P. Beamont, 87 Squadron, 15 May 1940
P/O F. B. Sutton, 56 Squadron, 18 May 1940
F/Lt. I. R. Gleed, 87 Squadron, 18 May 1940
F/O C. F. G. Adye, 17 Squadron, 18 May 1940
F/O C. F. G. Adye, 17 Squadron, 19 May 1940
F/Lt. I. R. Gleed, 87 Squadron, 19 May 1940
Sgt. L. H. B. Pearce, 79 Squadron, 20 May 1940
Sgt. J. C. Harrison, 229 Squadron, 28 May 1940
P/O C. M. Simpson, 229 Squadron, 29 May 1940
P/O K. B. McGlashan, 245 Squadron, 28 May 1940
