Geokoppmann:

Your enthusiasm is evident, and your interest in the environment is commendable. However, I wonder why you are seeing a drop of only 2 mpg when any chemical engineer will tell you that volumetrically, ethanol has about 26% less energy content. E85 should, therefore, have approximately 22% worse fuel consumption. While the AKI, or octane, is higher, your engine can not take advantage of that without remapping. So, something doesn't add up.

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