How to properly calculate numbers when switching fuel type?
 

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.

Fuelly isn't really set up to track bi-fuel vehicles, yet. We're working towards that goal however.

I would recommend having 2 separate vehicle profiles, one for each fuel type, in the meantime.

Is there any way I can single out a fuel up so it is not counted towards averages? Like when I switch to gas to e85, I will just use another profile, But that first fill up will be inaccurate with will throw all my averages off.

Or can I leave some fields blank?

Thanks!

I would track via trip miles, or ensure you check the 'missed fuel-up' option if tracking by Odometer.

I just start a "new car" in my garage in fuelly, using E10 in one "car" & E0(100% ethanol-free gasoline) in another "car" in fuelly.

I don't think you understand the problem.
Car has e10 gas, I fill up with e85. The data fields for my fill up are for e85 as I just filled it. BUT I was just driving with e10 so my mileage was for e10.

Problem will occur every time I switch fuel, thus making all of my average data inaccurate.

Also a problem with people who fill with different brands or octane ratings, if you fill brand A today and enter the mileage, the previous fill was Brand B, thus making your calculations of brand/octane off by one fill up. I personally average 2 mpg different between certain brands, making the cheaper brand more expensive per mile!

This is making me not enjoy the experience as I now know that the data is only accurate if you fill at the same place and fuel every time. That may work for average person. But for people like me who joined for the accuracy, it isn't accurate...

I will try to stick to e85 as long as possible, but when I can't find it, I will be forced to go back to e10 and thus reminding me that fuelly is not accurate and make me not want to use it anymore.

I see that you separated the profiles. So far 27+ vs ~21 for E85. Huge difference! Same type of driving?

Is BRZ actually flex fuel? If not, I don't recommend using E85 in it. Any "rubber" lines or gaskets in the fuel system likely won't stand up to the ethanol long term.

That said, the BRZ engine actually has a compression ratio that will take more of an advantage of ethanol's higher octane than the typical flex fuel engine, but it may be limited by injector size. Is there a noticable performance difference? I know that is why some Sonic modders go E85.