Help me understand E85

[lieu910]

I have been poking around threads trying to absorb what I can about E85, and I am still a bit unsure about it. I have a 2019 Bullitt, and am considering a tune. However, being in California I only have access to questionable 91 grade fuel, so the benefits of a tune are somewhat less than 93.

That said, there is E85 available here and here are my questions and concerns:

Is it in anyway harmful to the engine, fuel system?
Is a flex tune a safer way to go?

Sorry if these may be redundant questions, I have poked around here, but I am hoping someone has taken a similar journey and can speak directly to my concerns.

Thanks.

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[MOLL420]

491 WHP says DO IT!!!!!!!

 

[LOL WUT]

Not harmful to the engine or fuel system. Tons of people run a flex tune 100% of the time so they never have to worry about lower quality E85. However, running the flex tune requires your car to learn the ethanol content after every single fill up before you can get crazy with the go peddle. This can take anywhere from 5 to 15 minutes.

Personally, I run a dedicated E85 tune because it’s easier for me. I test my E85 before every fill (takes about 30 seconds) so I know exactly what I’ve got in the tank. Luckily over 1.5 years I’ve never seen less than E75 from my local station but I still test before every fill.

 

[Kennysum1]

It is about a 107 to 108 octane fuel. It will reduce your exhaust Temps a ton. It has insane amounts of knock protection. It allows you to run more timing safely.

It is the far superior fuel in every way. It won't damage anything and is actually better than pump fuel.

 

[Cordero1]

If you run cat-less, not many will notice with E85. Car will be more responsive & better. That being said, it will burn %30 (I think) faster than your regular unleaded.

 

[Kennysum1]

If you run cat-less, not many will notice with E85. Car will be more responsive & better. That being said, it will burn %30 (I think) faster than your regular unleaded.

You are correct it does use about 33% more fuel by volume. I should have put that it in my post. It will reduce your MPG. But should be a bit cheaper to off set this a little.

Wrong car to worry about MPG though.

 

[Cordero1]

You are correct it does use about 33% more fuel by volume. I should have put that it in my post. It will reduce your MPG. But should be a bit cheaper to off set this a little.

Wrong car to worry about MPG though.

Oh for sure, mpgs is nothing I ever worry about. But I do keep track of amount used being that I would go far when I'd race. So had to keep in mind how much I would use for runs & make sure I had enough to make it home lol

 

[Biggus Dickus]

E85 FTW. As you can see, CA has great E85/Flex Fuel:

https://www.mustang6g.com/forums/threads/the-so-cal-e85-report.123685/

San Diego is no exception - I suggest you go dedicated E85.

 

[tdstuart]

E85 is harder on the fuel system and engine long term. MMR mentions that some of the plastic timing components can be worn by e85 (although they are trying to sell products…). But in general ethanol is harder on plastics and your fuel system.

That being said the fuel system should be fine with e85. Ford has flex fuel vehicles and I believe they made the mustang fuel system ethanol safe.

Flex tunes are nice but like others have said you will have to be gentle on the car and drive it for 10-15 after changing fuel types / mixed.

I say go for it. You make lots of power, and it’s not that much more expensive to run (cheaper but burns faster). But if you do keep the car for a long time maybe do a timing component replacement and check the fuel system, but I wouldn’t worry about that till running e85 for like 80kmiles+. Maybe someone who knows more facts can chime in on that.

 

[lieu910]

Great info, thanks to all. The car is a on occasional weekend toy only, so the dedicated tune seems like the better option for me.

 

[NGOT8R]

I run it in my 2019 Bullitt. I actually have, 93 Pump Gas, E85 Race, Flex and E85 Nitrous tunes for my car. I live on the Flex tune most of the time, unless I want maximum power. I would suggest that you get any other mods that you have planned, installed before you tune, so that you can see maximum benefit from the tunes.

 

[Jackson1320]

E85 is harder on the fuel system and engine long term. MMR mentions that some of the plastic timing components can be worn by e85 (although they are trying to sell products…). But in general ethanol is harder on plastics and your fuel system.

That being said the fuel system should be fine with e85. Ford has flex fuel vehicles and I believe they made the mustang fuel system ethanol safe.

Flex tunes are nice but like others have said you will have to be gentle on the car and drive it for 10-15 after changing fuel types / mixed.

I say go for it. You make lots of power, and it’s not that much more expensive to run (cheaper but burns faster). But if you do keep the car for a long time maybe do a timing component replacement and check the fuel system, but I wouldn’t worry about that till running e85 for like 80kmiles+. Maybe someone who knows more facts can chime in on that.

the stock fuel system is ethanol compatible. gas has 10% ethanol in it so the system has to be compatible.

Great info, thanks to all. The car is a on occasional weekend toy only, so the dedicated tune seems like the better option for me.

if you don't mind testing your fuel at every fill up then e85 tune. if you want to gas and go like normal flex tune. i run a flex tune on a boosted setup and have no problems. just depends on you

 

[sk47]

Hello; If you have a way to watch, find Season 6 episode18 of ENGINE MASTERS Choosing Fuel: Which Barrel Is Right for you. If memory serves the episode compares running different fuels and has comments about the pros and cons of the fuels including E85.

One big advantage of alcohol fuels is the cooling effect.

 

[Magnetic Stang]

E85 really wakes up the coyote. Easiest extra horsepower you can get. The only con to running it is fuel economy like others have said. But if your car is weekend fun car going E85 is a no brainer. You won't regret it at all. I personally run a flex fuel tune because E85 isn't always convenient to get where I'm at.

 

[Stephen@lethal]

I have been poking around threads trying to absorb what I can about E85, and I am still a bit unsure about it. I have a 2019 Bullitt, and am considering a tune. However, being in California I only have access to questionable 91 grade fuel, so the benefits of a tune are somewhat less than 93.

That said, there is E85 available here and here are my questions and concerns:

Is it in anyway harmful to the engine, fuel system?
Is a flex tune a safer way to go?

Sorry if these may be redundant questions, I have poked around here, but I am hoping someone has taken a similar journey and can speak directly to my concerns.

Thanks.

If you have the fuel readily available I would 100% make the change. Like others have stated, it has incredible benefits, especially when you're in California and octane limited.

I would personally skip the Flex fuel tune and just do the straight E85 option as these vehicles are only able to use the widebands to adjust for ethanol and its just not very accurate compared to having an ethanol sensor in line.

If you need any help with a tune or have questions, feel free to reach out anytime. We have a wealth of knowledge here at Lethalperformance.com

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