Age Old E85 Question

[Martinrue97]

Hey all - have a few questions regarding e85. (23 Mustang GT 10r80)
Going to be taking the car out of winter storage and want to switch my car to E85 - car is currently tuned for 93. My tuner has a few files I can get - flexfuel and a straight up e85 tune. With that said can someone explain how a flexfuel tune would work? And for an e85 specific tune do I need to put exactly e85 in (ex: not e80 at my local pump) for this to work?

thanks, any Info will be helpful - never ran e85 before.

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[robvas]

Why not ask them instead of getting five different answers here?

 

[LOL WUT]

Flex tunes allow you to run any 1 type or mixture of fuel types. For example straight 93, straight E85, or any mixture of the 2.

Non flex E85 tunes are just that, setup for E85. Most tuners allow some variability, likely safe down to E70 or even lower. Some tuners will explicitly state to run tested E85 only.

At the end of the day, only your tuner can tell you how their specific tunes are calibrated.

 

[Martinrue97]

Flex tunes allow you to run any 1 type or mixture of fuel types. For example straight 93, straight E85, or any mixture of the 2.

Non flex E85 tunes are just that, setup for E85. Most tuners allow some variability, likely safe down to E70 or even lower. Some tuners will explicitly state to run tested E85 only.

At the end of the day, only your tuner can tell you how their specific tunes are calibrated.

Thanks for the help

 

[Cordero1]

Yeah when I had Lund they had me get a flex fuel & and e85r tune. One was for the varied levels of pump e85 & the other for tested e85.

 

[Martinrue97]

Yeah when I had Lund they had me get a flex fuel & and e85r tune. One was for the varied levels of pump e85 & the other for tested e85.

Okay so in other words if I’m not confident (testing we’ll say e70-e80) I should run the flex fuel tune and only the e85 tune when I’m testing 85 or above?

 

[K4fxd]

You are gen 3. In order to run a flex tune you need a tuner who can access all the parameters needed. The only commercial software that allows this is PCMtec.

I don't know if he is in the tuning business, but @engineermike is one I's ask for a gen3 flex tune.

A pro tuner I'd trust, based on communications with him, is @Wengerd Performance.

 

[NightmareMoon]

You’re asking questions you should be asking your tuner. Full stop.

 

[jpjr501]

A Gen3 with Flex Fuel? Let me know how that goes, I'm very curious.

I run E85 tune and I test my E85 before filling. It's roughly around 70-83% Ethanol. The tune will change timing accordingly.

I also have a 93 Tune but it's just for say trip driving when there aren't E85 stations accessible. BUT....not WOT runs allowed on 93 since I'm making over 10psi.

 

[stang17]

A Gen3 with Flex Fuel? Let me know how that goes, I'm very curious.

I run E85 tune and I test my E85 before filling. It's roughly around 70-83% Ethanol. The tune will change timing accordingly.

I also have a 93 Tune but it's just for say trip driving when there aren't E85 stations accessible. BUT....not WOT runs allowed on 93 since I'm making over 10psi.

Ask tuner if they offer canbus flex fuel tuning via PCMTEC. I had my buddy who now works for P1 Tuners set me up last year. Super convenient and works awesome.

 

[Martinrue97]

A Gen3 with Flex Fuel? Let me know how that goes, I'm very curious.

I run E85 tune and I test my E85 before filling. It's roughly around 70-83% Ethanol. The tune will change timing accordingly.

I also have a 93 Tune but it's just for say trip driving when there aren't E85 stations accessible. BUT....not WOT runs allowed on 93 since I'm making over 10psi.

Okay, that makes sense - moreso answering the main point of my question. What I was meaning to say was essentially I switch to e85 tune right - the ethanol content has to test somewhere in that 70-85 range to run it correct? My confusion here was that if I can’t get e85 that tests at 85+ I’d have to run a flexfuel tune.

 

[Martinrue97]

Okay, that makes sense - moreso answering the main point of my question. What I was meaning to say was essentially I switch to e85 tune right - the ethanol content has to test somewhere in that 70-85 range to run it correct? My confusion here was that if I can’t get e85 that tests at 85+ I’d have to run a flexfuel tune.

E85 is something I’ve never done before because it’s not exactly the most reliable to get in Jersey. So I’m a bit of a noob when it comes to this particular topic and want to make sure I’m more knowledgeable before getting a new tune from my tuner. He’ll have answers but I just want to hear others experiences beforehand

 

[stannypack]

My tuner set my dedicated "E85" tune to be 70+ since that's what I tested my gas station at. You can use the flex fuel tune if you're going on a road trip or something and don't want to run all the ethanol out of the tank.

 

[jpjr501]

Okay, that makes sense - moreso answering the main point of my question. What I was meaning to say was essentially I switch to e85 tune right - the ethanol content has to test somewhere in that 70-85 range to run it correct? My confusion here was that if I can’t get e85 that tests at 85+ I’d have to run a flexfuel tune.

Yes, you want the best E85 possible. It'll say on the pump that the content may be lower than 85%, it's normal. The tune will adjust accordingly.

BUT...avoid the crappy stations with low content. Get the E85 app and read the comments. Was about to put E85 at a station, read the comments, said he tested it at 40% several times. I had enough left in the tank to get to the Turnpike Plaza that always tests over 72%.



Here is the tester I have. It's old school but as you can see, tested over 75%.

 

[Martinrue97]

Yes, you want the best E85 possible. It'll say on the pump that the content may be lower than 85%, it's normal. The tune will adjust accordingly.

BUT...avoid the crappy stations with low content. Get the E85 app and read the comments. Was about to put E85 at a station, read the comments, said he tested it at 40% several times. I had enough left in the tank to get to the Turnpike Plaza that always tests over 72%.



Here is the tester I have. It's old school but as you can see, tested over 75%.

Yeah fortunately I have two spots I would go to (a 30 min drive will fill up some cans) but the one is near a track and regularly tests e78 and above in spring and summer which is when I’ll be using it

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