[badbread]

I've gotten a few PM's lately asking about my car and more specifically how to e85. I have some reservations about telling someone how to add e85 when my knowledge is there but is still pretty limited. I decided it was time for a blog post with my experience using e85.

MY goal using e85 as I wrote on my blog, make California's crappy 91 octane gas a little more palatable to the car, increase the octane rating. Some posts say it doesn't, some say it does. What's the truth?

Here's a little gif (not JIF) I made showing the difference in timing corrections on the MHD beta when using...

Just 91 octane:
[IMG]https://i0.wp.com/*************/wp-content/uploads/2018/02/noE85gif.gif[/IMG]

And using 91 octane with a little E85 mixed in:
[IMG]https://i0.wp.com/*************/wp-content/uploads/2018/02/E85timinggif.gif[/IMG]

Same car, same tune, same mods, 10º difference in weather, much better timing, does the above prove e85's ability to perform as an octane booster?

Link to the blog post

Back at it, I've bounced the post off a couple people, received some thoughts and knowledge but would really like some place to discuss the various things going on when using e85.
I understand I may be complicating something simple but there's a lot going on under the hood and having a deeper understanding really peaks my interest.
There are so many posts out there on all the forums regarding e85, how you should and shouldn't use it, how it's awesome, how it's the worst stuff ever, etc... It would be nice to have some data, some facts, some real life experience, etc.. in regards to using e85.

I was hoping to have an open discussion here about your thoughts and experiences on e85 usage.

What to look for in logs when spiking your tank with e85?
Timing, fuel rail pressure, and other logging parameters?
Ethanol maps vs higher octane maps when using e85, etc..?
Measuring ethanol content?
Your experience with e85 blends (As the .gov guidelines seem pretty variable)
Summer vs winter blends, etc...

To start things off, I was curious how one would determine if they were using to much e85.

Someone (Thanks Joseph) in the MHD beta chat was courteous enough to explain that a potential sign in logs of using to much e85 would be your rail pressure mean psi (aka FP_H in the JB4 world) dropping below 1600 PSI.

At first I didn't get it, to me it seems counter-intuitive, I would just assume the rail pressure would get to it's highest PSI rating and just not produce more power because it can't pump anymore, but I was wrong.

Because e85 doesn't have as much energy as gasoline the injectors... inject more fuel and as a result of that, the rail pressure drops because the fuel pump can't keep up with all that extra fuel flowing out.

I hope I'm not the only one that didn't know that but yea...




Thanks again everyone and looking forward to learning some stuff.

[Mike@N54Tuning.com]

I think you need to decide on what tune you are running first as E85 use will be very different depending if you are running a JB4 which can adjust for E -mixes or a flash map that is made for a SPECIFIC mix.

Mike

[badbread]

Good point Mike, so in the jb4's case, the flex fuel wire measures ethanol content and makes adjustments on the fly, correct? Is that only when using map 5?

I'll clarify my post above as being with mhd's tune.

Thanks!

[jgoens]

I don't have any stats on E85 but have been using it for years--when I had an e90 and now with my f30.

I use it usually three weeks of the month and my routine is 4.5 gal e85 and the rest 91. For the sake of comparison, I have used straight 100 octane as well as a blend of 100, e85 and 91 but found my usual blend to be the same as far as how the car runs.

Everything I have to say is subjective, but the car not only is faster with e85 but seems to run better. The cat-less dp smell is less. One curious thing that could be my imagination, but happens most of the time is that the car seems to be particularly fast and peppy once I get down to a 1/4 tank and this is not because of weight reduction as I don't feel that with just straight 91.

So, I would be a strong proponent of e85 usage for jb4 users with FF wires.

[badbread]

I was able to get in touch with the CEO of Pearson Fuels, they are the largest distributor of E85 in California, here is his response:

Originally Posted by Mike Lewis CEO of Pearson Fuels

"That is a great question because the labels that we are required to post on the dispensers by different government agencies can be very confusing. While we do have the ability to vary the blend seasonally, in reality, all the E85 we blend in the entire state is calculated to be blended at 83.3% ethanol. We regularly do field testing and the fuel almost always comes back within 1-2% of 83.3%. This little variance can probably be attributed to variances in the evaporation rates of ethanol and gasoline and the fact that a big tank of thousands of gallons might have some variation throughout the tank, much like you might have an alcoholic drink that can be stronger at the bottom or top.

The California Air Resources Board allows us to blend at a rate lower than 83.3% but if we did that then the price of E85 would have to go up about $.20 per gallon because we would then be subject to state excise tax which we are exempt from now. It is a conflict between air pollution regulations and tax laws so it should continue to be 83.3% unless we make a big social media announcement one day, which we do not see on the horizon.

Very rarely, we will have a blend that is not at the 83% (less than 1% of the deliveries). In that case, if it is still legal E85 then we will sell it and put a sign on the pump that says "Attention Racers: This E85 is blended at XX%. This a temporary situation and when this sign is removed it will revert to 83%". I think that has happened 2-3 times in the history of the company so it is very much the exception. Every once in a while someone will contact us and tell us that the blend percentage is off or we hear chatter on the social media and when we test the fuel almost every time the blend is right near 83%."

I've highlighted some particular areas of interest.

They seem like a really cool company especially seeing that last highlighted point.

They also have an E85 station finder app for both iPhone and Android the California folks, I found out my local E85 station is supplied by them.

[badbread]

And some info from Pearson fuels about their Octane rating:

Originally Posted by Pearson Fuels

Our Octane is about 103 research Octane. Research is expensive to test for (about $1,500) and the enforcement agencies don't really test for it so people get away with claiming whatever they want to claim. The one time we tested for it, it was 103.1 Research Octane. Most of the time in our brochures we just say it is 100+ Research Octane to account for any variability but most of the time it is very close to 103.

There is another E85 supplier that likes to claim their E85 is 105 octane, we would love to see someone take a picture of the label on their pump and then call them on it and ask to see the results to prove it is 105. We don't think it is that high.

[Mike@N54Tuning.com]

Originally Posted by badbread

Good point Mike, so in the jb4's case, the flex fuel wire measures ethanol content and makes adjustments on the fly, correct? Is that only when using map 5?

I'll clarify my post above as being with mhd's tune.

Thanks!

In essence.. It can adjust fuel volume.. E85 requires more fuel to run..

Mike