I have done a lot with e85 over the years and one of the largest issues are , it is the only unregulated fuel in the US for cars.
You might go buy it one time and it be 99-101 octane then next time be 92-95 octane this wouldnt do well for an engine needing say 100 octane fuel , e85 is highly resistant to knock but somewhat sensitive to preignition, the sensitivity of preignition is what causes the actual octane rating to go down , what people dont understand is e85 isnt 105 octane
The 2012 has a wide band o2 that as you change fuels from say 93 to e85 which needs 27-30% more fuel will make the adjustments to add the needed / targeted fuel and keep the air fuel safe
Those reading this that have a 2011 or older MUST get a retune or you will blow the engine
I will not run e85 even if it was given to me , for evey guy that says they have run it for years problem free I can show you 2 that have blown there engines
This discussion will never be resolved this will go on for years and there will always be guys that love e85 so to each there own just know what your getting into before you use it
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