There
drive through Nebraska on I-80 sometime... we did this a few years ago
this was at the station, which would you pick if you were running a 91 octane tune?
View attachment 17303
btw - I picked E85 and got 9.9MPG for the next 300 miles (this was in my Raptor with a 36 gallon tank)
You should look also at the gas mileage thread. If I were just trying to get good highway mileage I'd be shooting for a low ethanol content. All things being equal, you'll get better mileage from a higher gas content for
part-throttle driving. Ethanol is a great fuel for racing, but if we're just talking about cruising, every 10% in ethanol is about 3.3% less mileage.
So a 30% mix is right around 10% loss in mileage. All calculations based on 114,000 btu per gallon of gas vs 76,100 btu per gallon of ethanol.
edited for fat fingering 3%!