Ethanol Blend Discussion

[b4black]

You're right. And I think that was SM105K. Also we have to pay attention to this "Flex Fuel" BS at the pump that has 50-85% ethanol. E85 has to have at least 70% ethanol to be E85. "Flex Fuel" and "E85" are not the same.

Flex Fuel and E85 are the same thing. Different names for the same fuel. Needs to meet ASTM D5798.

Nearly all Flex Fuel/E85 is 83% ethanol in the summer. It's only when it's cold is more gasoline needed for easier starting.

I run E30 often in my car with a 93 Unleashed tune. LTFTs drift up a little. Actual fuel rail pressure stays right at the desired pressure.

 

[b4black]

What should I watch out for if I run too much ethanol? Seems like I could run much more %ethanol - the LTFT have room to go up, the fuel rail pressure is OK, the AFR is right at the desired lambda, no knock retard.

 

[SM105K]

Flex Fuel and E85 are the same thing. Different names for the same fuel. Needs to meet ASTM D5798.

Nearly all Flex Fuel/E85 is 83% ethanol in the summer. It's only when it's cold is more gasoline needed for easier starting.

I run E30 often in my car with a 93 Unleashed tune. LTFTs drift up a little. Actual fuel rail pressure stays right at the desired pressure.

Your statement isnt completely accurate. The pumps here in AZ run E51 year around. They are labeled Flex Fuel. Everytime I put fuel in the car I test it.

My logs in the ST on my Flex Fuel Tune also confirm this as well.

 

[FiveLeeter918]

here to be considered "E85" it must be a minimum of E70. "Flex Fuel" pumps are minimum E50 and seldom see over E60.

 

[Angrymongoose]

Around here each brand seems to have their own range of what E85 is. I've seen one that said anywhere from 53% to 81% and others have different ranges. Seems to make about as much sense as cell phone carriers "unlimited" plans.

 

[b4black]

here to be considered "E85" it must be a minimum of E70. "Flex Fuel" pumps are minimum E50 and seldom see over E60.

Not true, unless there is some state specific law. There is only one spec - ASTM D5798. It was called E85 and then the name was change to Flex Fuel when the lower limit was dropped to E51 in 2012. E85 was never a proper name for a fuel that never has 85% ethanol, but that's the name that stuck early on. After ASTM change the name and the EPA started mandating warning labels, the name started to change towards Flex Fuel.

Older E85 labels will say 70% minimum. Newer Flex Fuel labels will say 51%. But there is nothing forcing "E85" to be 70% any longer.

Read about E85 on Wikipedia:
In the United States, the exact ratio of fuel ethanol to hydrocarbon may vary according to ASTM 5798 that specifies the allowable ethanol content in E85 as ranging from 51% to 83%

Here is the D5798 spec: https://webstore.ansi.org/Standards/ASTM/ASTMD579818a


If you still think I am wrong, please copy a link to support your view.

 

[b4black]

Your statement isnt completely accurate. The pumps here in AZ run E51 year around. They are labeled Flex Fuel. Everytime I put fuel in the car I test it.

My logs in the ST on my Flex Fuel Tune also confirm this as well.

Interesting. I wonder why would they sell only 51% when the ethanol is much cheaper than gasoline.

AZ law requires the fuel meet D5798. It could be that instead of changing the ratio seasonally, they just stick to 51% and then never need to worry about being off spec.

 

[FiveLeeter918]

Not true, unless there is some state specific law. There is only one spec - ASTM D5798. It was called E85 and then the name was change to Flex Fuel when the lower limit was dropped to E51 in 2012. E85 was never a proper name for a fuel that never has 85% ethanol, but that's the name that stuck early on. After ASTM change the name and the EPA started mandating warning labels, the name started to change towards Flex Fuel.

Older E85 labels will say 70% minimum. Newer Flex Fuel labels will say 51%. But there is nothing forcing "E85" to be 70% any longer.

Read about E85 on Wikipedia:
In the United States, the exact ratio of fuel ethanol to hydrocarbon may vary according to ASTM 5798 that specifies the allowable ethanol content in E85 as ranging from 51% to 83%

Here is the D5798 spec: https://webstore.ansi.org/Standards/ASTM/ASTMD579818a


If you still think I am wrong, please copy a link to support your view.

Just reporting how our local stations designation. I'm a mechanical engineer, dont deal with energy conversions much. All I know is I have an ECA and when I use the "Flex Fuel" pumps its ALWAYS between 51-60% and when the pump says E85 its ALWAYS 70% or more.

Same company, same metro area, 100 Ethanol stations, very different labels and different measurements.

 

[SM105K]

Interesting. I wonder why would they sell only 51% when the ethanol is much cheaper than gasoline.

AZ law requires the fuel meet D5798. It could be that instead of changing the ratio seasonally, they just stick to 51% and then never need to worry about being off spec.

Considering there are only like maybe 10 stations that sell E straight from the pump, and like 8 of them are Chevrons the probably just use that blend. However....

https://www.dsmtuners.com/threads/no-more-e85-in-arizona.506096/

First post has a letter that explains why.

 

[4sfed]

https://www.dsmtuners.com/threads/no-more-e85-in-arizona.506096/

First post has a letter that explains why.

So Smoke....have you actually measured your E content? Given that E85 is more toward E70-ish, do you find that your E50 is more toward E30-ish?


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[SM105K]

I measure the Flex Fuel when I put fuel into the SHO. It regularly sits at E50-54 here in AZ year around, like the law states. I mix it with 91 and that is the E30 mix that goes into my SHO. I check it because the SHO is picky and try to run it at 33% Ethanol. That is its sweet spot.

The ST gets straight Flex Fuel. The AJPTurbo Flex Fuel tune absolutely rips and it doesn't matter if I put in 87 or E85 it adjusts accordingly. My only gripe is, I can't keep my damn foot out of it and my mileage is really suffering.

Ford did the fuel system and gauges correctly in the Focus ST. No fuel mods needed to run E85 and all the gauges that are needed for a turbo car.

The SHO is completely ass backwards. No gauges, crap HPFP, no dedicated Flex Fuel tune ability. They really dropped the ball.

 

[b4black]

Thanks for the link to the letter.

E54 is not the AZ law, but the Jet Companies deciding to blend to the most conservative ratio to stay on spec and sticking with it all year. We have a company in Illinois that sticks with E75 all year. Most others move up and down with the seasons.

 

[High on Ethanol]

What should I watch out for if I run too much ethanol? Seems like I could run much more %ethanol - the LTFT have room to go up, the fuel rail pressure is OK, the AFR is right at the desired lambda, no knock retard.

When I run "too much ethanol" I essentially run out of fuel with maxxed out fuel trims and dropping rail pressure.