I just got word today that the gas we get out here is 87 octane, but it has 10% ethanol or alcohol added. Does anyone know how much the ethanol or alcohol would raise the octane level?

I was hoping it was 89 octane out here, but I guess it isn't.

The ethanol in E-10 Unleaded adds two to three points of octane to ordinary gasoline.

Not sure what E-10 is.

There's got to be some people on here that understand this more than I do. :)

E-10 means 10% Ethanol 90% regular unleaded. Ethanol has an octane rating of about 113. So blended with 87 octane unleaded would yield about 89 octane. Also at about 10% ethanol you can see a decrease in MPG by about 2-3%. This is due to the lower energy content of ethanol.

Thanks! That's the information that I wanted.