Better mpg with Ethanol?

[Gonzo]

I have a question. I was getting around 19 hwy using Chevron gas (low octane). So one day I decide to get the cheapest stuff I can find. It was at a co-op, and has 10% ethanol and is also low octane. Now with this "cheap" gas I average 21 hwy! What's up with that? I remember reading a discussion in here about how ethanol burns cleaner, but reduces gas mileage. Has anyone ever heard of anything like this?

 

[kkreit01]

You must have been going with the wind, the weather was warmer, you were going downhill, or you were lucky. Most people get less MPG on ethanol -- although the Iowan farmers may disagree with that statement..

 

[Gonzo]

I know it wasn't wind, temperature, or downhill, because I have made 3 different trips, with 3 different tanks, all with the ethanol gas, same route, same temperature (maybe + - 5 or 10 deg.) I even tried a tank of the non-ethanol gas, and the mileage went back down to 19. This is all on the highway though. I haven't checked the in-town mpg yet.