Good for you! I did almost the same using a spreadsheet.
I printed the spreadsheet and put a copy under my sun visor.

In the mid-west you might find ethanol as lower cost ( per mile ) than gas.
The farther you are away from the corn belt, it gets more expensive.

Bottom line, it will be very close to the cost per mile of gas.
It may cost you a penny more, or a penny less, so cost should not be your #1 motivation.