@Tfmonkey ​Ethanol does have a higher octane rating than straight gasoline but its a pretty marginal improvement even though its 10% of pump gasoline by volume. Most of the anti-knock agent in gasoline is actually methyl tert-butyl ether (MTBE). Ethanol also causes premature rubber and seal failure and it readily absorbs humidity from the air which causes a massive reduction in the motor octane number (MON) in less than 3 months. Ethanol is a horrible fuel for most mission profiles.