[Tijeras_Slim]

I thought it was Shell that first made 100 octane and Jimmy Doolittle was involved.

[DuncanWaring]

According to the Wikipedia article on tetraethyl lead GM and DuPont discovered in the 1920s that it increased octane.

Encyclopedia Brittanica tells roughly the same story.

https://en.wikipedia.org/wiki/Tetraethyllead#History

https://www.britannica.com/science/tetraethyl-lead

[Flag_This]

"I thought it was Shell that first made 100 octane and Jimmy Doolittle was involved."

You're right on both counts:

"Well versed in high-performance engines and their fuel requirements, Doolittle began pushing the oil company to go into production while simultaneously convincing military brass to order a few thousand gallons of 100-octane aviation gas. Tests in 1934 at Wright Field near Dayton, Ohio, confirmed Doolittle's suspicions when the Army Air Corps reported 20 to 30 percent improvements in power without any increase in operating temperatures. At the time, aviation fuel was typically 87 octane, and high-octane automobile fuel just 77 octane." Link

Jimmy Doolittle was a Man.