Military History
Jimmy Doolittle, Hap Arnold, and the Battle of Britain: The 100-Octane Story
Changing to 100-octane (100/130 aviation gasoline) just before the Battle of Britain increased the speed of the Spitfire by 25-30 M.P.H. at low and medium altitudes and made it equal, or superior, to the German Me 109 at all altitudes.