How do I know how much ethanol left in my gas tank?

[ysjeon1698]

I put 6.64G of 85 and filled rest with 93 octane (4:6)

Now... How do I know how much of ethanol left in my gas tank without the kit? lol....

I want to match the ratio to 5:5

help!!


Also, I'm taking my car to dyno this Sat. Can someone give me a tip? first time here!

 

[Cheezy]

If you have the ethanol test tube you can pull the fuel line from the injector, reattach it to the fuel rail off to the side and put a container under it, then unlock and lock the car, the fuel pump will prime the injectors and voilà you get fuel out of your system to test. You may have to prime them twice to get enough fuel, or set up a catch under two injectors. Your original fuel mixture works out to be e41ish if the pump was really e85. I'd say drive it and throw another 1.5gal of e85 in. If you're over e50 by a little it will be fine, you just don't wanna be under

 

[P33P33]

First you need to check how much you have left in the tank. Then you can calculate how much you need to put E85 into tank.
Do you want ratio of 50/50 re85/93RON (this is ~E45%) or true E50%?
I made excel table to calculate these things. But first you need to know how much you have left in the tank. You can check that from hidden menu https://www.youtube.com/watch?v=SkVYNr8EZqE it's number 6 to see tank info.

 

[ldyzluvdis06]

Just guess. If you calculate it at the fill up, now just put 10 gallons In and you will know the ethanol. I never fill up anymore because i don't know how much fuel it will take to fill. So if I always jut put 10 gallons in, I can always calculate the actual content.

 

[KevinC39]

And don't forget all of this assumes that the E85 you're getting out of the pump is actually 85% ethanol which it probably isn't from my experience.

 

[Xshadows]

This is why it's worth spending the money and getting the FUEL-IT ethanol analyzer.

 

[Cheezy]

Just guess. If you calculate it at the fill up, now just put 10 gallons In and you will know the ethanol. I never fill up anymore because i don't know how much fuel it will take to fill. So if I always jut put 10 gallons in, I can always calculate the actual content.

I also use the 10 gallon method, it keeps math simple. If you don't have the fuel it ethanol analyzer I would suggest at least getting the ethanol content test tube and testing the pump every two weeks

 

[ldyzluvdis06]

Agreed! I test it every couple of fill ups.