Originally Posted by
Chu Chu
Are octane ratings from the 1940s directly comparable to modern ones? The octane rating depends on the test used (e.g. the numbers are different for the same mogas in the U.S. and Europe), so the scale might have changed at some point after the war. Or it might not have.
Might find this article interesting. It's titled "The difference between 100/130 and 100LL but there is some history of Avgas from WWII on.
https://generalaviationnews.com/2007...130-and-100ll/