Running E85

[AHP]

You can get away with ~E30 all day. The benefits/gains without a JB4 (more boost) or a real tune would not be significant. Stock tune on 93 can be pretty stingy with timing advance once the IATs start creeping up so in a high performance situation there would be some benefit.

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[FriedPickles]

Owners manual explicitly states to not use anything over E25, so I’d say the juries out on longevity of parts if you want to use E85. Guaranteed they don’t design for the quantity of ethanol in the fuel supply in Europe like we get here in the U.S.

 

[zrk]

Owners manual explicitly states to not use anything over E25, so I’d say the juries out on longevity of parts if you want to use E85. Guaranteed they don’t design for the quantity of ethanol in the fuel supply in Europe like we get here in the U.S.

Right. The fuel system won't handle it for long, you'll run lean and go pow pow.

 

[AHP]

If you're going to quote the manual, you should definitely stick to it. ?

 

[Sereph102889]

Owners manual explicitly states to not use anything over E25, so I’d say the juries out on longevity of parts if you want to use E85. Guaranteed they don’t design for the quantity of ethanol in the fuel supply in Europe like we get here in the U.S.

This is because if you run more than E25 on the stock tune, you will run lean do to insufficient fueling via the tune, not via the fuel systems capabilities or limitations. Basically, do not mess with an E-blend at all unless you're tuning for it because you will not be able to take advantage in the slightest.

 

[zrk]

not via the fuel systems capabilities or limitations

Disagree, but ok.

 

[AHP]

In my personal testing with basic bolt-ons the stock "tune" has trims comfortably sufficient up to E30 - E35. In controlled conditions (don't try this at home, kids) you can push it in to the low 40% range before it will max the trims and eventually throw a lean code.

 

[Sereph102889]

Disagree, but ok.

So if E25 is roughly the limitation of the stock fuel system itself, why is it that almost every tuner offers E30 OTS, E40 OTS, and E40-E50 custom maps all on the stock fuel system, but all of those same tuners will tell you to not mix above E50 because that's when you start to run into fuel system limitations. I'm genuinely curious how so many people run these tunes and how they almost seem to be standard in this community if E25 is the safe limitation.

You know more about this stuff than I do, that's for sure, but I figured there was enough data at this point to suggest that E40-E50 was reasonable? Is it just a "it's fine for a matter of time" type of thing, or is it just that the stock fuel system shouldn't even be pushed beyond E25 in the first place, but everyone is doing it anyways? There's always conflicting information to be found on the internet, so asking questions to better understand both sides of the argument is always a good idea.

 

[Xproplayer]

If your asking this question. You should not be modding your car yourself……. Take it to a performance shop that knows what they are doing……

 

[Sereph102889]

Totally agree.

 

[Mason]

Totally agree.

Agree, but ok.

 

[SD_MK]

In my personal testing with basic bolt-ons the stock "tune" has trims comfortably sufficient up to E30 - E35. In controlled conditions (don't try this at home, kids) you can push it in to the low 40% range before it will max the trims and eventually throw a lean code.

Agree, i can attest to this. Was doing it in my car for a while before i got my DP and Tune.. sheeeit i was doing this in my Evo before THAT was modified. ??

 

[zrk]

So if E25 is roughly the limitation of the stock fuel system itself, why is it that almost every tuner offers E30 OTS, E40 OTS, and E40-E50 custom maps all on the stock fuel system, but all of those same tuners will tell you to not mix above E50 because that's when you start to run into fuel system limitations. I'm genuinely curious how so many people run these tunes and how they almost seem to be standard in this community if E25 is the safe limitation.

You know more about this stuff than I do, that's for sure, but I figured there was enough data at this point to suggest that E40-E50 was reasonable? Is it just a "it's fine for a matter of time" type of thing, or is it just that the stock fuel system shouldn't even be pushed beyond E25 in the first place, but everyone is doing it anyways? There's always conflicting information to be found on the internet, so asking questions to better understand both sides of the argument is always a good idea.

I meant on stock tune. The fuel system will handle E40ish, E50ish in somecases, as long as the cars knows it needs to dump fuel. This is why E40-E50 JB4 cars need meth. JB4 can't add fuel, car will run lean, and kaboomybang.

 

[zrk]

Relevant XKCD.

 

[Sereph102889]

I meant on stock tune. The fuel system will handle E40ish, E50ish in somecases, as long as the cars knows it needs to dump fuel. This is why E40-E50 JB4 cars need meth. JB4 can't add fuel, car will run lean, and kaboomybang.

To quote what I had said previously and make some wording changes so that we better understand lol.

"This is because if you run more than E25 on the stock tune, you could run lean due to insufficient fueling via the tuning, not via the fuel systems capabilities or limitations of hardware. Basically, do not mess with an E-blend at all unless you're tuning for it because you will not be able to take advantage in the slightest."

I guess I didn't speak correctly because what I meant to get across was roughly exactly what you said here lol. Basically, The fuel system as hardware can work with E40-E50, but the car itself, on the factory tune, would not know to dump more fuel because it wouldn't be tuned for that specific mixture from the factory.

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