E85 in a gen3

[IronJay]

So how critical is the change in pump E85 if we plan for the E50 blend? Pump can vary on E% depending on time of year and each batch. Do i really need to test tube each fill up or is there enough cushion in the tune of the E% is off a few points? I really don't wanna test tube each fill up, that's a pain in the ass!

If i stick with the correct E85 gallons per fill up I should be fine if I wanna run the E50 blend tune? If i have to test each batch of E85 i'll most likely pay for bigger injectors so I don't have to F with it!

Please post your experience.

 

[Braaaaptor]

Anecdotally, my experience is that there's a decent amount of leeway in the tune (I'm using Goosetune). I have accidentally overfilled to about E60 and did not grenade my motor. Mind you, I babied it for about 50 miles and continually topped up to slowly lower that ratio. I believe Winfield states that the tune is safe between E40-E60 but so your own DD depending on what tune you use.

The above is the one horror story I have with E50 tunes. I tested my local pump twice (once in the winter and once in the summer) and saw no changes. If I'm going on a trip or otherwise find myself away from my regular pump - I use the same brand of ethanol for consistency sake. For me in Northern CA - Pearson Fuel has a huge ethanol pump network so for trip planning I use their app to find a Chevron and Pearson station. Using that method has been working for me for the last 3 years.

If you're constantly changing where you get ethanol or enjoy getting discounted or budget gas then it may be worth it to test what you're using.