Answer to Avgas Octane Question
50 octane.
In the 1920s, aviation fuel octane ratings were about the same as that of automotive fuel: 50 octane. In 1926 however, Graham Edgar of the Ethyl Corporation discovered that fuel having a higher content of a paraffin with the chemical formula of C8H18 (and known as isooctane) could be burned at higher compression ratios before knocking occurred. The US Army adopted 87-octane fuel in 1930, and by 1937 it had been generally adopted in civilian aviation as well. In 1936 however, the Army began using 100-octane, and by World War II it was in standard use for military aircraft.
HT: Jeff Pardo of
i-Pilot.
