We're not going to add sorting by best MPG for the reasons outlined here:
Why don't you list everything in order of best fuel economy?. Basically, we don't want to encourage bad data.
We've talked about tracking different fuel grades in the past. Currently we just distinguish fuels based on the type of fuel a vehicle consumes. So Gas, Diesel, CNG, LPG, Flex, and Hybrid are tracked separately. Those are based on what the vehicle consumes. There are different grades of gas, and my understanding is that e85 is a grade of ethanol gas, not necessarily related to the type of engine that can consume it. You could note which tanks you fill with e85 in the notes or tags for that fuel-up. But for now there's no separate tracking, just as there's no separate tracking for different octane levels.
__________________