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Feature Article: Hundred Octane Aviation Fuel
Interestingly of all machines, only airplanes have their own fuel
In the late 1930s light weight and compact engines were being
developed with compression ratios that required fuels not subject
to detonation. 100 octane began as a scientific curiosity by blending
70 octane with chemicals such as tetraethel lead and hydrogen
to get the higher octane.
In 1938 an alkylation process by Humble Oil greatly increased
the possible production of 100 octane. Cold acid alkylation made
it possible to raise 1943 production of 100 octane to 15,000,000
gallons per DAY! However, full power engines still encountered
detonation. The solution was to use fuel additives that would
become effective to prevent detonation at full power operations
but at lower powers were adjusted to lower octane. 100/130, 91/95,
and 80/87 aviation octane fuels became the norm.
By mid-1940 all British fighters were converted to operate on
100/130. This change allowed manifold pressures to be raised from
42 to 54 inches. This gave every engine an effective 30% increase
in power. Now, tell me, what won the Battle of Britain.
Chandelle is French from montrer en chandelle, which means climb
around a candle.
Last Modified January 25, ©2026 TAGE.COM
