[TJay74]

Originally Posted by G2K

To me the hassle is having to use 2 credit cards every time I fill up since my bank freaks out when I use the card back to back. Having to actually go to twice the transaction is a big PITA for me. Then comes the what if i want to run 5gals for mexico nights vs filling up for everyday driving. I find myself constantly having to check, calculate and see after If i got the mix right if not (which in my case is most of the time) ANOTHER stop to the gas station to bring E% content down.

I hand mix mine just like King, it is super easy and if you get a OBD2 Bluetooth adapter and have the Ethanol sensor it is super easy to check and see where you are at.

Basically here is all I do. I know at a half tank I will need roughly 10 gallons to fill up to full. A 6th gen Camaro gas tank is 19.8g. I then take what my current Ethanol rating is (say E41) and multiply it by 10g = 410 points.

Now if I am trying to get to say E50 I start playing with the math. Say I put in 7 gallons of E85, that will give me another 595 points. Then I add the 410 + 595 and get 1005 points.

Then divide the 1005 points by 19.8g and you get E50.76.

So once I know where my math needs to be to get me to the Ethanol value I want, I put the E85 into the tank 1st for how ever many gallons I need to hit the desired value, then I top off with pure 91 octane 100% gas to help mix it up.

So far from my testing I am pretty spot on, I am usually with in 2-4 points of what the Ethanol sensor reports once the fuel has mixed. I used to have an excel spreadsheet I made to do the math, it made it super quick to figure out how much E85 to add to the system.

Now if I could just figure out why my high side isnt holding as well as it should, I am limited around E40 right now for some reason.