Ethanol has about 30% less energy per volume...This translates to the more E you run the more fuel you have to physically flow to make the same air fuel ratios. This is why guys running E85 install 1000+cc injectors, they need them.
Its true that large mixes improve octane ratings a lot. In fact I have a buddy in the lower 48 that tunes with E85 and he claims you basically cannot make it knock. You can reach MBT (basically max power with timing) on the stuff without knock in most cases so its definitely a win, however the trade off is sucking down gas really fast!
That being said low percentage mixes like the one your talking about are probably not big game changers. We don't have any thing like that here in Alaska so no recent experience here. I only know what I read and understand about the stuff.
I'm sure there might be some threads that speak directly to the ethanol questions around here somewhere...
Originally Posted by 05_wRex
Also, is there a consensus as to whether 93 octane with up to 10% ethanol is better or worse for our cars? As far as tuning goes that is. I don't mean its adverse effects on carburetors and all that. Ethanol has a higher octane rating that gasoline, correct? So it would make sense that it wouldn't be any lower than 93 octane. At least that's my line if thinking and why I'm asking, because I don't know for sure.