I really didn't need an EPA study to figure out that ethanol isn't good for engines. It seems like I have my own test lab down in my basement. Every time I go to use a chain saw. edger, weed eater, tiller, or anything else I have that isn't used frequently, the carburetor will be clogged up and I'll have to take it apart and clean or rebuild it to get it running. I happened last weekend with a pole saw I use two or three times a year.
Ethanol alcohol is water soluble and can attract and absorb water. Ethanol alcohol can dissolve plastic, rubber, fiberglass and even aluminum over time. All of that is bad news for engines in general and certainly for Burgman engines.
As greginnm points out in the post above, it doesn't provide the same energy as pure gasoline, so, your engine requires more fuel to do the same thing pure gasoline does.
I try to get pure gasoline when I can, particularly for gasoline powered engines that aren't used frequently. Somehow, I don't seem to be very good at adding Seafoam or other additives when I should.
It's interesting that you've done the math on this. I might of guessed that this might be the outcome comparing to pure gasoline, but it's nice that you've done the study for us.Last year we logged our mileage. Running 87 octane mixed gas, our mileage was 12% less than when running premium, 93 octane pure gas. Doing the math, high-octane gas is actually cheaper to run.