As a kid I remember adding "Gas Line Antifreeze" to a tank of gas to prevent water separation - was alcohol.


Back in the '20s Boss Kettering and Tom Midgley discovered the effect of lead on knocking engines. But first they found that alcohol was better, it just took too much: 10%.


Something the gas companies do not tell you is that 87 PON starts out as about 81-82 octane gas (cheaper to make than hi-test) then they add the ethanol to get 87 (or 89, or 93).