How to properly calculate numbers when switching fuel type?

[swarbrz]

So I am switching from Gas E10 to E85, is there a way I can accurately enter the data fields?

For example, I just finished my gas and pour in e85. I enter the fields for the e85 I just pumped, But the car was driven with Gas. Any way to separate the calculations for different fuels?

The calculation for mpg is off as the last was gas and current fill is e85.
Also cost per mile is off because I just drove with gas(higher mpg) and refueled with e85(cheaper) which messes all the numbers up.

Any ideas?

The only other idea I can think of is to have a profile for each fuel type, but it ends up being difficult to calculate if I switch fuels.