Why do you say ethanol degrades performance? Ethanol is an anti-knocking agent when added to gasoline, so it actually enables higher performance.
In other words, today's gasoline in US takes you 4% less distance than gasoline from 70s.
It also creates problems with internal corrosion (which is why it is not used in aircraft fuels), though modern auto engines are designed to deal with that (and are more expensive because of that, too).