You are focusing only on high octane rated "hot rod" fuel, never
mentioned tetra-ethyl lead

the discussion was regarding alcohol.

tetra-ethyl lead came about from reaseach done by General Motors in 1920 on
ways to improve the quality of gasoline ("normal" octane of the times were
about 65, though 100 octane gasoline was produced -- at huge expense -- for WW1
aircraft engines). Several compounds were found to be useful increasing
"octane rating" of gasoline without super-expense refining. The very best of
those compounds was tetra-ethyl lead. The second best -- by some distance --
was a chemical still commonly used by farmers to reduce fungus growth on their
crops [sorry I don't recall the name]. the GM vice-president in charge of the
reasearch project left GM at project's end to form The Ethyl Corporation
(apparently with GM's blessing). This was all reported in The Petroleum
Institute of America Journal [Apr/May ? 1921?], an original copy of which I
read in 1981. Find a copy and read it if you wish.