1. 13.9 gal. Combined with my Cobb AP fuel level reading, its been giving me accurate mixing according to my ethanol readerI have some questions for those of you running e30/40:
1. Do you use 13.4 gallons or 13.9 gallons for tank size? There is a discrepancy between Ford Media and the workshop manual.
2. If the pump says 93 octane contains up to 10% ethanol, do you automatically assume it's 10% when putting it in the calculator?
3. Do you fill up when exactly at half or a quarter tank to make the math easy off whatever number you use in question 1?
2. I usually get 10-12% ethanol on the 3-4 gas stations I frequent, so I think 10% is a good assumption.
3. Before having an ethanol reader, I've been doing as you had suggested, only filling up at half or near empty. I was also using my Cobb AP fuel level to help me with the calculations. I started filling up with E30 whenever once I had my ethanol reader installed.
I would also suggest you measure the ethanol content of your E85 before mixing. This should help getting your mix closer to ideal.