Originally Posted by 1turbofocus
I will be the bad guy here and say DONT use e85 , the ecu doesnt need time to learn the o2 , the o2 will make changes faster then you can see it needs changing even on e85 this is what gets a lot of people in trouble they dont understand e85 / Tuning and think its a wonder fuel and it isnt
It the most / only unregulated fuel in the US which should say a lot, its never a 103 - 105 octane like people say your lucky if its even 93 when they get through with it and why they dont have to put the octane on the pumps , it has less energy , less MPG and under WOT the ecu has NO WAY to adjust for the fueling unless your in a 2012 or newer Focus and running 100% e85 you need to add 26 - 30 % more fuel which nothing older then a 2012 Focus can do at WOT with any fuels
The IRL did go to "E" fuels but the octanes were strictly regulated and they did have much higher octanes then anything ever sold at the pumps
Yes I have seen gains in TQ with running e85 then he returned 4 days later with e85 from another station and was down on power and had spark knock because the blend wasnt the same as his car was tuned for , most guys are not as lucky as he was and they tow the car home
My opinion till they regulate the octane its JUNK fuel , 95% of all the guys over the years that raved about e85 have stopped using it because of failures
There is a ton of misinformation out there about this fuel , best thing I can say is do a LOT of homework before using it
I don't claim to be an expert on this subject but, I will say I have ten years of experience with using a blend of E85 here in Minnesota with no negative effects at all and I DO see a gain in mileage and performance. You can listen to all the negative information out there about ethanol or, you can take it from someone with experience. Just understand, I am not advocating that anyone run full E85 in a non flex fuel vehicle. That WILL create problems with your system. I am only suggesting a 20-30% blend,
You are correct that the ECU makes very quick adjustments to the fuel/air mixture. What happens with the ethanol is that it sees it as a lean mixture due to the higher oxygenating effect of the ethanol. The computer makes big adjustments to compensate for a lean mixture, hence the possible drop initially. Then the ECU makes much smaller adjustments over time to get to a balance. That is why you may initially see a drop but it will stabilize after a tank or two when it sees this as the new normal. The ECU does learn or driving habits and compensates accordingly.
I will drop the subject at this post. I know I am in a small minority of people who have long experience with ethanol.