When to use Flex fuel/E85?

swathdiver · December 12, 2017

E-85 can have anywhere from 51% to 83% ethanol. The higher the content, the worse your mileage will be. I took on 22 gallons the other day and am about 1mpg lower than normal, about 13.2 right now but that is what my whole last tank of 93 averaged. Have had times when the average for E85 was between 10 and 12 mpg. If we knew which blend we were getting then I would use it more often or not. It's barely $2 a gallon right now in my area.

Grumpy Bear · December 12, 2017

Well if you are racing I think I mention that as an exception, right? Do you race? Do you truck pull or is it a dyno monkey? If so it makes sense.

BTW, you are not thinking Lingenfelter just went to Circle K and bought some E-85 are you? I make all these exceptions in my original post. By the very nature of an internal combustion engine part throttle power for a given load is just a slight change in TPS. They are demand devices. If the hill is asking for 75 hp in a zero G accent then it doesn't matter if the motor makes, at WOT, 500 or 5000 hp. Throttle will open far enough to generate 75...period at whatever the road speed requires for rpm. For this to make any noticeable difference in day to day driving one of those two pedals will need to be flat on the floor 100% of the time OR you motor didn't make 75 hp to begin with.

Grumpy Bear · December 12, 2017

40 minutes ago, swathdiver said:

E-85 can have anywhere from 51% to 83% ethanol. The higher the content, the worse your mileage will be. I took on 22 gallons the other day and am about 1mpg lower than normal, about 13.2 right now but that is what my whole last tank of 93 averaged. Have had times when the average for E85 was between 10 and 12 mpg. If we knew which blend we were getting then I would use it more often or not. It's barely $2 a gallon right now in my area.

Your trucks ECM has an address for the Alky % that can be read with a Scan Gauge II or like device. Problem is, it's after the fact. Is there a test kit?

KARNUT · December 12, 2017

Well if you are racing I think I mention that as an exception, right? Do you race? Do you truck pull or is it a dyno monkey? If so it makes sense.

BTW, you are not thinking Lingenfelter just went to Circle K and bought some E-85 are you? I make all these exceptions in my original post. By the very nature of an internal combustion engine part throttle power for a given load is just a slight change in TPS. They are demand devices. If the hill is asking for 75 hp in a zero G accent then it doesn't matter if the motor makes, at WOT, 500 or 5000 hp. Throttle will open far enough to generate 75...period at whatever the road speed requires for rpm. For this to make any noticeable difference in day to day driving one of those two pedals will need to be flat on the floor 100% of the time OR you motor didn't make 75 hp to begin with.

I guess your still referring to me. I’m not racing anymore but I’ve done enough to be able to feel a difference in performance. My truck ran better on E-85 even at part throttle. At the time it was cheaper to run than reg gas. As I stated I would have paid more for what I was feeling. Early in 2014 there was a lot of testing because these were new engines and E-85 self tuning was new. Some areas were getting different blends so results may vary. You may have different results and claim BS. I’m suggesting you may want to go back in this site there was plenty of testing in the summer of 14.

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Grumpy Bear · December 13, 2017

Both of you actually but...I'm not calling BS on anyone. I have no idea what you can feel in the pants or what your local conditions are. All I was saying is....I made those exceptions. That part is getting ignored for whatever reason.

I don't argue physics and I don't argue math. Silly really. They are what they are. If someone tested with lab grade (SUNOCO E-85R) and got a million more horsepower, so be it. It just ain't happening on pump on commercial fuel.

KARNUT · December 13, 2017

There you go again, car and driver, Black Bear, lingenfelter, and the few people who posted E-85-reg gas runs at the track, ran on pump gas. Maybe in your area E-85 sucks, there has been lots of positive results testing E-85 just on this site alone. Your testing on your truck is just one of many.

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sdeeter19555 · December 13, 2017

In my very new and limited flex fuel experience, e85 definitely made my truck feel better, smoother. WOT is also a lot better feel (e.g., merging onto interstates). Had 125k miles of seat time with this truck...notable difference as soon as the truck realized it had different fuel (I can see percent alcohol with my Insight).

Mileage sucks...but not as bad as I expected.

I won't go out of my way to buy it, but I would run it when available...

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Grumpy Bear · December 13, 2017

If you guys can tell a difference between 93 E-10 and E85 at 51% which are both 93 (R+M)/2 NASA is calling your number. Seriously. There isn't one inch ounce difference in torque even possible. That's just physics.

Your also trying to get me to believe that somewhere in the USA the E-85 is always 85% and 100 octane. SUNOCO calls BS on that. I don't have to. Not buying it.

Your further trying to convince me that places like BB and Lingenfelter are tuning on whatever they got at Walmart today labeled E-85 and that kids I will call BS on. If they say they are they are lying out their a**. It's a 'can' tune. A can of SUNOCO or similar fuel.

What I will believe is that these guys absolutely do a 100 octane tune and publish it. GM did and BB/Lingenfelter will. Getting that tune without knock retard or getting that fuel is less likely. You may get a labeled E85 tune that is dialed in for 51% and seven points less octane. Or maybe even a 100 octane tune that will always be in retard and as such not delivering what their dyno numbers did. Why? Fuel supply. It goes in a circle. They can test and publish anything they like and will if it sells product. Did they lie? Not by the definition of E-85 supplied by the law. 51% minimum.

I'll even buy that the literature shows huge gains, dyno proven. They better at 12 points of octane between 87 and 99. That pump is a liar if it says more and likely isn't that much. Repeat. See Sunoco for details.

If it is your argument that the difference between 87 and 93 is noticeable then I'm buying some of that. But only at WOT and under enough load to exceed the factory limit. But I already have that tune from the factory. That one keeps HC and NOx in check. Know what else it does? Lets me merge onto I-355 at part throttle with a V6. It's the fastest piece of interstate in Illinois. Trooper proven. That place is a ticket machine.

Smooth is a term used to describe vibration. Frequency and amplitude. I'll buy any story that comes equipped with a strip chart from a monitor. The rest is physics. If your saying you don't take a major hit in mpg using E-85 then your fuel isn't 85% ethanol. You can BS a reader but mother nature never.

swathdiver · December 13, 2017

12 hours ago, Grumpy Bear said:

Your trucks ECM has an address for the Alky % that can be read with a Scan Gauge II or like device. Problem is, it's after the fact. Is there a test kit?

Ohh yeah I can read that with my Tech2. Like you said there really isn't a way to tell before you pump it in what your getting.

KARNUT · December 13, 2017

Amazing just Amazing. You just can’t be wrong. Boys and Girls do your research.

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sdeeter19555 · December 13, 2017

I'm out....

Steve
2012 2500hd 6.0l

Cowpie · December 13, 2017

13 hours ago, swathdiver said:

E-85 can have anywhere from 51% to 83% ethanol. The higher the content, the worse your mileage will be. I took on 22 gallons the other day and am about 1mpg lower than normal, about 13.2 right now but that is what my whole last tank of 93 averaged. Have had times when the average for E85 was between 10 and 12 mpg. If we knew which blend we were getting then I would use it more often or not. It's barely $2 a gallon right now in my area.

I guess that depends on location and state requirements. E85 in Iowa is required to be a minimum of 70%. Folks should check with their state weights and measures people to find out what the requirements are.

Over the years of using ethanol blends, the best one in terms of mpg combined with performance and cost has been the E30 blends. Only if one has the blender style pumps where they can select E10, E15, E20, E30, and E85 is that really an option. Unless one wants to do the double pump thing and hand calculate.

Grumpy Bear · December 13, 2017

5 hours ago, KARNUT said:

Amazing just Amazing. You just can’t be wrong. Boys and Girls do your research.

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Yes I can and I was and here's how...But it doesn't change my mind and that will become evident.

I need to clarify something. When I said there was not one inch ounce more torque in 51% E-85 that 93 gasoline I meant on the basis of Octane thus compression. I did not make that evident. My crow was served with jam.

Some facts. The densities of ethanol and gasoline are pretty close. Close enough that comparisons can be made on the basis of percentages. Some fuel facts:

Gasoline BTU/pound = 19,344 Best power AFR 12.5:1

Ethanol BTU/pound = 12,500 Best power AFR 6.4:1

As the motor is an air pump the fuel doesn’t change its swept volume so to find the power potential of Ethanol we have to find the equivalent fuel load. Easy peasy. 12.5 / 6.4 = 1.95 the ratio of best power ratios.

Next we multiply this by the heat content of Ethanol so 12,500 * 1.95 = 24,414. Then divide by gasolines heat content or 24,414 / 19,344 = (1.26 X 100) – 100 = 26%

This means if the motor were fueled on straight Ethanol it would make 26% more power all things equal. It would also use almost twice as much fuel under full load WOT conditions. A 300 hp gas motor might make 364 hp on ethanol. Tax grade alcohol. We lose a 1.5 hp to the effect of denatured.

We don’t have pump E100 and even if we did it wouldn’t have a heat content of 12,500 per pound. Why? ATF regulations prohibits sale of straight grain alcohol in the USA without a tax stamp. By law ethanol is ‘denatured’ with 2% hydrocarbon distillates. E 98 is as good as it would get. That also means E85, subject to the same rules could never have more ethanol content than 83%.

Quoting injectordynamics.com:

The original specification set the minimum ethanol content at 75% which was lowered to 68% in June of 2010, and lowered again to 51% in June of 2011. As of February 2012, this is the current specification and E85 purchased from the pump could have an ethanol content as low as 51% and still be within spec.

So we have a range and to not belabor the math the range of possible power increases is 13% at 51% ethanol and 22% at 83% ethanol.

The factory tune gives roughly a 7% increase so the range is now 6% to 15% of additional power with a dedicated tune to a specific alcohol content.

Based on oxygen balance 83% would use 48% more fuel and 51% would use 25% more fuel in under cruise conditions.

If straight up pump E-10 87 cost $2.39/gallon (todays price) the price of E-85 needs to fall between $1.62 (@83%) & $1.92 a gallon (@ 51%) to break even.

Here’s the rip. Locally E-85 is running about 65-70% and costing $1.68/gallon. (today). Charged like the real deal. Delivering like a racehorse with a broken leg.

Paying $400 or so for an E-85 tune to get about a 8-10% power boost that cost me 3-5% at the pump every time I fill AND not always getting my full measure of power means it has to be done for nothing but the power because the economics just don’t work. It’s the gift that keeps on taking.

Then there is this last dagger in the heart. As most report no more than a 10% decline in mileage it means that what is in your TANK is a blend of some unknown alcohol content E-85 and whatever you filled up with in the meantime. To get your money’s worth, I repeat again, your tank needs to be full of 85% content race grade fuel.

BTW, I did check on Lingenfelter. It was ‘certified’ E-85 aka race grade.

cmysstailights · December 13, 2017

In eastern lower ny, 87 is 2.59 e85 1.59

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KARNUT · December 13, 2017

Yes I can and I was and here's how...But it doesn't change my mind and that will become evident.

I need to clarify something. When I said there was not one inch ounce more torque in 51% E-85 that 93 gasoline I meant on the basis of Octane thus compression. I did not make that evident. My crow was served with jam.
Some facts. The densities of ethanol and gasoline are pretty close. Close enough that comparisons can be made on the basis of percentages. Some fuel facts:
Gasoline BTU/pound = 19,344 Best power AFR 12.5:1
Ethanol BTU/pound = 12,500 Best power AFR 6.4:1
As the motor is an air pump the fuel doesn’t change its swept volume so to find the power potential of Ethanol we have to find the equivalent fuel load. Easy peasy. 12.5 / 6.4 = 1.95 the ratio of best power ratios.
Next we multiply this by the heat content of Ethanol so 12,500 * 1.95 = 24,414. Then divide by gasolines heat content or 24,414 / 19,344 = (1.26 X 100) – 100 = 26%
This means if the motor were fueled on straight Ethanol it would make 26% more power all things equal. It would also use almost twice as much fuel under full load WOT conditions. A 300 hp gas motor might make 364 hp on ethanol. Tax grade alcohol. We lose a 1.5 hp to the effect of denatured.
We don’t have pump E100 and even if we did it wouldn’t have a heat content of 12,500 per pound. Why? ATF regulations prohibits sale of straight grain alcohol in the USA without a tax stamp. By law ethanol is ‘denatured’ with 2% hydrocarbon distillates. E 98 is as good as it would get. That also means E85, subject to the same rules could never have more ethanol content than 83%.
Quoting injectordynamics.com:
The original specification set the minimum ethanol content at 75% which was lowered to 68% in June of 2010, and lowered again to 51% in June of 2011. As of February 2012, this is the current specification and E85 purchased from the pump could have an ethanol content as low as 51% and still be within spec.
So we have a range and to not belabor the math the range of possible power increases is 13% at 51% ethanol and 22% at 83% ethanol.
The factory tune gives roughly a 7% increase so the range is now 6% to 15% of additional power with a dedicated tune to a specific alcohol content.
Based on oxygen balance 83% would use 48% more fuel and 51% would use 25% more fuel in under cruise conditions.
If straight up pump E-10 87 cost $2.39/gallon (todays price) the price of E-85 needs to fall between $1.62 (@83%) & $1.92 a gallon (@ 51%) to break even.
Here’s the rip. Locally E-85 is running about 65-70% and costing $1.68/gallon. (today). Charged like the real deal. Delivering like a racehorse with a broken leg.
Paying $400 or so for an E-85 tune to get about a 8-10% power boost that cost me 3-5% at the pump every time I fill AND not always getting my full measure of power means it has to be done for nothing but the power because the economics just don’t work. It’s the gift that keeps on taking.
Then there is this last dagger in the heart. As most report no more than a 10% decline in mileage it means that what is in your TANK is a blend of some unknown alcohol content E-85 and whatever you filled up with in the meantime. To get your money’s worth, I repeat again, your tank needs to be full of 85% content race grade fuel.
BTW, I did check on Lingenfelter. It was ‘certified’ E-85 aka race grade.

Maybe because so many people were singing the performance benefits of E-85 back in 2014 I was hit with the placebo effect. It sure felt good, I’m human.

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