[hellokitty]

EPA also did a study researching the impact of an E20 blend. See slide 6.

http://www2.epa.gov/sites/production...s_glickman.pdf

Emissions / temperature
−
Regulated tailpipe emissions with E15 and E20 were similar to levels
with E0.
•
NMHC and CO decreased slightly (CO flat from E10
-
E20).
•
Ethanol and acetaldehyde emissions increased as expected.
−
Under most conditions, catalyst temperatures were largely unchanged
with E15 and E20 compared to E0.
−
Under full throttle conditions, about half of the cars exhibited increased
catalyst temperatures with E15 and E20 compared to E0.

Drivability
−
Drivability issues were not identified with either E15 or E20.
−
No malfunction indicator lights or filter plugging.
−
Informal observations only.

Fuel Economy
−
Fuel economy on volumetric basis decreased for E10, E15, E20.
−
Closely tracked fuel energy content.

[Isaiah5411]

So...we're scrapping all of the negative press about ethanol (including premature engine component wear) for a little more (purported) HP? I'm not convinced...yet. Remember what happened to all of the 335 fuel injectors and high pressure fuel pumps when they first arrived in the US and had their first taste of E10/E15? Was it all BMW's fault or did the ethanol really play a role??

Call me weird, but I'm doing the opposite...mixing 93 octane E10 50:50 with 89 octane non-ethanol gas to get 91 octane gas with less ethanol in it. (The owner's manual of my 2008 328i recommends 91 octane fuel but says that 87 octane can be used if necessary.)

Note: (From Wikipedia, if you believe this source.)

Corrosion in non-E85 fuel systems

Fuel systems and engines not designed or modified to use E85 may experience increased wear and may fail prematurely. Some (particularly older) fuel systems and those used in powersports and agricultural engines contain rubber seal elements which have excellent gasoline resistance but poor ethanol resistance. These systems generally can accept up to E10 without major degradation in service life of susceptible seal components.

Octane rating
The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests."

Are these guys wrong? http://www.fuel-testers.com/list_e10_engine_damage.html

So...is there really enough added octane in E85 to warrant subjecting your engine to more ethanol? By the time you've diluted it as described, the increase in octane becomes even more negligible while the percentage of ethanol is significantly increased.

Seems to me we're playing with fire here. Just my $0.02.

[MannySingh]

If i wish to increase my octane to 93 by adding 2 gallons of ethanol to my 91 pump gas that I have in california, would I have to flash the 93oct map or would I have to flash to an ethanol map or what?

Im using MHD

Anyone get what im trying to ask?

[JM98]

Originally Posted by MannySingh

If i wish to increase my octane to 93 by adding 2 gallons of ethanol to my 91 pump gas that I have in california, would I have to flash the 93oct map or would I have to flash to an ethanol map or what?

Im using MHD

Anyone get what im trying to ask?

With that small of a difference you wouldn't have to flash a new map. Are you looking for a safety margin with higher octane or more power? If you want more power you can benefit from a higher octane map as it will have more timing and boost.

[JM98]

Originally Posted by Isaiah5411

So...we're scrapping all of the negative press about ethanol (including premature engine component wear) for a little more (purported) HP? I'm not convinced...yet. Remember what happened to all of the 335 fuel injectors and high pressure fuel pumps when they first arrived in the US and had their first taste of E10/E15? Was it all BMW's fault or did the ethanol really play a role??

Call me weird, but I'm doing the opposite...mixing 93 octane E10 50:50 with 89 octane non-ethanol gas to get 91 octane gas with less ethanol in it. (The owner's manual of my 2008 328i recommends 91 octane fuel but says that 87 octane can be used if necessary.)

Note: (From Wikipedia, if you believe this source.)

Corrosion in non-E85 fuel systems

Fuel systems and engines not designed or modified to use E85 may experience increased wear and may fail prematurely. Some (particularly older) fuel systems and those used in powersports and agricultural engines contain rubber seal elements which have excellent gasoline resistance but poor ethanol resistance. These systems generally can accept up to E10 without major degradation in service life of susceptible seal components.

Octane rating
The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests."

Are these guys wrong? http://www.fuel-testers.com/list_e10_engine_damage.html

So...is there really enough added octane in E85 to warrant subjecting your engine to more ethanol? By the time you've diluted it as described, the increase in octane becomes even more negligible while the percentage of ethanol is significantly increased.

Seems to me we're playing with fire here. Just my $0.02.

Been running E40 for 6 months with no issues and wouldn't change a thing. If you look at ethanol maps vs. pump gas maps, you'll see they make much more power. Ethanol provides knock resistance and cooler combustion temps. It's a tradeoff either way, I'll lean towards making more power with a decent safety margin vs. longevity of the fuel system components.

[MannySingh]

Originally Posted by JM98

With that small of a difference you wouldn't have to flash a new map. Are you looking for a safety margin with higher octane or more power? If you want more power you can benefit from a higher octane map as it will have more timing and boost.

So it would be safe to add 2 gallons of e85 to my car without any sort of tune just to boost my octane to 93?

[JM98]

Originally Posted by MannySingh

So it would be safe to add 2 gallons of e85 to my car without any sort of tune just to boost my octane to 93?

Yes

[GripAndRip]

Just so I'm understanding this correctly..... I don't need to modify or get an aftermarket fueling system to run E30 map for MHD? Anyone on here having any issues running E30 on stock fueling system?

[madmantwo]

Originally Posted by GripAndRip

Just so I'm understanding this correctly..... I don't need to modify or get an aftermarket fueling system to run E30 map for MHD? Anyone on here having any issues running E30 on stock fueling system?

You should be fine as long as your LPFP is healthy. I did it, but not regularly. Just do some logging and watch LPFP pressure under heavy load. If it dips to around 50psi or lower (someone correct me on that number if I'm wrong), you need auxiliary fueling.

[GripAndRip]

Originally Posted by madmantwo

You should be fine as long as your LPFP is healthy. I did it, but not regularly. Just do some logging and watch LPFP pressure under heavy load. If it dips to around 50psi or lower (someone correct me on that number if I'm wrong), you need auxiliary fueling.

Also, no one seemed to answer whether the 10% E in 91 is accounted for or not. So for every 10 gallons of 91 you are getting 1 gallon of ethanol right? E85 is mixed to be 85% ethanol right? Sorry if these are dumb questions, but based on this I can make a calc to share.

[GripAndRip]

If you account for the 10%E in 91. Then in 10 gallons pump gas you are getting 9 gallons gas and 1 gallon E. if you were to assume summer and tested the E85 to be truly 85% E and 15% gasoline then for 4 gallons E85 you get 3.4 gallons E and .6 gallons gasoline. So with a 10/4 gallon ratio like some have said, you are getting 9.6gas/4.4E ratio. That's a 45.8% mixture.

[GripAndRip]

I've been looking at a lot of the online calculators and they don't seem to be accounting for the ethanol in the gasoline correctly. For example, they are coming up with 4 gallons of E85 and 10 gallons of 91 @10% equaling E32. They are assuming 3.4 gallons ethanol and 10.6 gallons gasoline.

Originally Posted by GripAndRip

I've been looking at a lot of the online calculators and they don't seem to be accounting for the ethanol in the gasoline correctly. For example, they are coming up with 4 gallons of E85 and 10 gallons of 91 @10% equaling E32. They are assuming 3.4 gallons ethanol and 10.6 gallons gasoline.

Use a different calculator:
http://www.georgebelton.com/E85Calculator.php

93 in my area is actually 7% ethanol, so I adjust that figure to accommodate.

[GripAndRip]

Originally Posted by FCobra94

Use a different calculator:
http://www.georgebelton.com/E85Calculator.php

93 in my area is actually 7% ethanol, so I adjust that figure to accommodate.

According to the calculation I just mentioned, this calculator is wrong. That or I am. But this calculator isn't really account for the ethanol that's already in the gas. I see that it has a place to enter the % and it may affect the calculation. But it isn't coming out with the right numbers.

[GripAndRip]

Originally Posted by FCobra94

Use a different calculator:
http://www.georgebelton.com/E85Calculator.php

93 in my area is actually 7% ethanol, so I adjust that figure to accommodate.

The formula for that calculator is as follows:

((Gallons gas)(%ethanol) + (gallons e85)(%ethanol))/(total fluid gallons).

But aren't the ratios (gallons ethanol)/(gallons gasoline) ?

Essentially that calculator is providing
(Gallons ethanol)/(gallons gas +gallons ethanol)

Originally Posted by GripAndRip

The formula for that calculator is as follows:

((Gallons gas)(%ethanol) + (gallons e85)(%ethanol))/(total fluid gallons).

But aren't the ratios (gallons ethanol)/(gallons gasoline) ?

Essentially that calculator is providing
(Gallons ethanol)/(gallons gas +gallons ethanol)

No, you're looking at it totally one sided...

Your equation is simply calculating the ratio of one product to another; that might be good for figuring out what percentage of sugar you've add to flour, etc. but not much else.

The calculator I linked takes it one step further to specify the overall CONTENT of ethanol as it equates the specific value of each product (gasoline and ethanol; neither of which is 100% pure) to the total sum of product calculated after mixing both together.

[GripAndRip]

Originally Posted by FCobra94

No, you're looking at it totally one sided...

Your equation is simply calculating the ratio of one product to another; that might be good for figuring out what percentage of sugar you've add to flour, etc. but not much else.

The calculator I linked takes it one step further to specify the overall CONTENT of ethanol as it equates the specific value of each product (gasoline and ethanol) to the total sum of product after mixing both together.

I think I misunderstood what the correct ratio is. The e ratio isn't ethanol/gasoline like I thought . It's ethanol/total fluid

Would you agree that e85 is a gasoline with 85% ethanol mixed to it? So 85% of the total volume of e85 is ethanol. As in, if you have 4 gallons of e85, 3.4 gallons of the total volume is ethanol and .6 gallons is gasoline. 10 gallons of E10(91OCT) would be 9 gallons gasoline and 1 gallon ethanol. My ratio, which was ethanol to gasoline, for these numbers would be (3.4+1)/(9+.6) = .45

But if it's ethanol to total fluid... then the calculators are fine (3.4+1)/(10+4) = .31. Or E30 essentially.

I believe my question has been answered. Thanks! I'm gonna get a tester to try this out.

[Aqid]

Actually, the E85 here in Colorado is only E70 (it literally says at the pump, 70% ethanol blend). I'm sure it goes up and down a little bit, but in this case lets say we have a 70% ethanol blend and a 10% ethanol blend (91/93 gas).

So then 4 gallons of "E-85" and 10 gallons of gas would be:

"E-85":
4 * 0.7 = 2.8 gallons of ethanol
4 * 0.3 = 1.2 gallons of gas

Gas:
10 * 0.1 = 1.0 gallons of ethanol
10 * 0.9 = 9.0 gallons of gas

Total:
2.8 + 1.0 = 3.8 gallons of ethanol
1.2 + 9.0 = 10.2 gallons of gas

3.8 / 10.2 = 37.25%

So the end result would be a 37.25% ethanol blend. The thing that bothers me, is what kind of gas do they mix e85 with? I assume 87.

So when calculating octane you're looking at:

3.8 gallons of ethanol @ lets say oct 100
9.0 gallons of gas @ oct 91
1.2 gallons of gas @ oct 87

First we need to find the value of our oct 91 gas, since it's 91 with the E85 blended in. Not without.

So if we keep assuming the pure ethanol has an octane rating of 100, than

10 * 91 = 910 (total octane)
1 * 100 = 100 (one gallon of ethanol)
(910 - 100) / remaining 9 gallons = 90

So our 91 pump gas is 9 gallons of octane 90 and 1 gallon of octane 100 creating 91.

If we take those numbers and calculate that into the overall E blend:

3.8 * 100 = 380
9.0 * 90 = 810
1.2 * 87 = 104

(380 + 810 + 104) / 14 gallons = 92.42 average octane between those 3

That's really only a boost of 1.4 octane over the pump 91. Now some say pure ethanol rates at 105, others say its 95 - so I took 100 as average.

A better thing to do is to find ethanol free 91, which allows you more gallons of e85 in order to get to your E30-E40 blend. In that case I think you're closer to 9 gallons of 91 and 5 gallons of E85.

That's:
9 gals of 91
1.5 gals of 87
3.5 gals of ethanol

which is 3.5 / 10.5 = 33.33% ethanol blend, giving you

9 * 91 = 819
1.5 * 87 = 130
3.5 * 100 = 350

(819 + 130 + 350) / 14 = 92.8 octane

In that case you're looking at a slightly higher octane level (92.8 over 92.4) while using a slightly lower ethanol blend (33% over 37%).

[GripAndRip]

Originally Posted by Aqid

Actually, the E85 here in Colorado is only E70 (it literally says at the pump, 70% ethanol blend). I'm sure it goes up and down a little bit, but in this case lets say we have a 70% ethanol blend and a 10% ethanol blend (91/93 gas).

So then 4 gallons of "E-85" and 10 gallons of gas would be:

"E-85":
4 * 0.7 = 2.8 gallons of ethanol
4 * 0.3 = 1.2 gallons of gas

Gas:
10 * 0.1 = 1.0 gallons of ethanol
10 * 0.9 = 9.0 gallons of gas

Total:
2.8 + 1.0 = 3.8 gallons of ethanol
1.2 + 9.0 = 10.2 gallons of gas

3.8 / 10.2 = 37.25%

So the end result would be a 37.25% ethanol blend. The thing that bothers me, is what kind of gas do they mix e85 with? I assume 87.

So when calculating octane you're looking at:

3.8 gallons of ethanol @ lets say oct 100
9.0 gallons of gas @ oct 91
1.2 gallons of gas @ oct 87

First we need to find the value of our oct 91 gas, since it's 91 with the E85 blended in. Not without.

So if we keep assuming the pure ethanol has an octane rating of 100, than

10 * 91 = 910 (total octane)
1 * 100 = 100 (one gallon of ethanol)
(910 - 100) / remaining 9 gallons = 90

So our 91 pump gas is 9 gallons of octane 90 and 1 gallon of octane 100 creating 91.

If we take those numbers and calculate that into the overall E blend:

3.8 * 100 = 380
9.0 * 90 = 810
1.2 * 87 = 104

(380 + 810 + 104) / 14 gallons = 92.42 average octane between those 3

That's really only a boost of 1.4 octane over the pump 91. Now some say pure ethanol rates at 105, others say its 95 - so I took 100 as average.

A better thing to do is to find ethanol free 91, which allows you more gallons of e85 in order to get to your E30-E40 blend. In that case I think you're closer to 9 gallons of 91 and 5 gallons of E85.

That's:
9 gals of 91
1.5 gals of 87
3.5 gals of ethanol

which is 3.5 / 10.5 = 33.33% ethanol blend, giving you

9 * 91 = 819
1.5 * 87 = 130
3.5 * 100 = 350

(819 + 130 + 350) / 14 = 92.8 octane

In that case you're looking at a slightly higher octane level (92.8 over 92.4) while using a slightly lower ethanol blend (33% over 37%).

You are making the same mistake I was making above. You and I are calculating the ethanol/gas ratio, while everyone else is calculating ethanol/total volume.

[Aqid]

I guess I'm not grasping the difference yet. So with what you're saying, having an E70 blend, how many gallons of that would I need to add to E0 91 pump gas to go over octane 93?

[GripAndRip]

Originally Posted by Aqid

I guess I'm not grasping the difference yet. So with what you're saying, having an E70 blend, how many gallons of that would I need to add to E0 91 pump gas to go over octane 93?

You know what made me realize I was doing it wrong? Calculate out E70 from just E70. So 1 gallon. 1 gallon of E70 contains .7 gallons E and .3 gallons gas right by definition?

.7/.3 is not .7 or 70% and that's using your and my ratio idea of ethanol/gasoline

[GripAndRip]

Originally Posted by GripAndRip

You know what made me realize I was doing it wrong? Calculate out E70 from just E70. So 1 gallon. 1 gallon of E70 contains .7 gallons E and .3 gallons gas right by definition?

.7/.3 is not .7 or 70% and that's using your and my ratio idea of ethanol/gasoline

This is how all the calculators and everyone else seems to do it and how E85 would be calculated too (or E anything)

You can also use any number of gallons (16 if empty or whatever the sum of the two fluids is). You can also account for previous fills depending on what was in your tank before.