E85 Octane.... 105, 97 or something else????

T

twinrats

Turbo Lover
Joined
Jul 16, 2007
Just found a local E85 gas station this weekend...was all excited about the "cheap" 105 octane race gas :biggrin: When I went inside to pay for the 5 gallons I wanted to pump into my GN, I asked the guy behind the counter if he has seen many people with Performance cars buying the fuel for the 105 octane rating of the stuff or just Geenies trying to save the planet?

He told me the "state" was just in checking the quality of the fuel and was told it's 97 Octane :mad: . I also noticed there was no listing on the pump about the octane rating. What's the real deal on the octane??? Do any of you know?
 
twinrats said:
Just found a local E85 gas station this weekend...was all excited about the "cheap" 105 octane race gas :biggrin: When I went inside to pay for the 5 gallons I wanted to pump into my GN, I asked the guy behind the counter if he has seen many people with Performance cars buying the fuel for the 105 octane rating of the stuff or just Geenies trying to save the planet?

He told me the "state" was just in checking the quality of the fuel and was told it's 97 Octane :mad: . I also noticed there was no listing on the pump about the octane rating. What's the real deal on the octane??? Do any of you know?
Click to expand...


E85 is at or about 105 octane. Period.
 
the octane rating is misleading anyway because it is an average of the two methods of obtaining an octane number.

E85 has a higher Research octane number than 116 leaded race gas, and in our applications this is the more important number. This is why you see people running e85 able to duplicate 116 performance.

The E85 cooling effect has a great impact that gasoline does not have.
 
This weekend with a mix of 3 gallons 100 unleaded and 3 gallons E-85 (on the pump it said 105 octane) I pushed 23lbs of boost thru a Te45a with no knock..:D
 
Scooter3800 said:
This chart should help you out...

E85 Mustangs.com - Regional Fuel Chart by state

Depending on the month you may not be getting E85, more like E80 or less
Click to expand...
Thanks Scooter....this is more like what I thought was going on...E85 may NOT ALWAYS be 105 Octane. Since the three blends vary in alcohol content. According to the chart NONE of the blends are actually 85%! They go from 80 to 70%. If a 85% mix is 105, then what would 70% be? Could it be 97????
 
Just did a quick yahoo search of E100 (100% Ethanol) and found it is 106 octane...so 105 octane for 85% sounds too high..if it's mixed 50% with 87 octane regular gas that would come out to 96.5 octane blend, the Winter 70% blend should come out to 98.4 based on percentages, still good but way off of 105!
 
twinrats said:
Just did a quick yahoo search of E100 (100% Ethanol) and found it is 106 octane...so 105 octane for 85% sounds too high..if it's mixed 50% with 87 octane regular gas that would come out to 96.5 octane blend, the Winter 70% blend should come out to 98.4 based on percentages, still good but way off of 105!
Click to expand...

E100 is not 106, IRL, Indy Racing League uses it now instead of Methanol, i believe it was close to the mid 11x's. The reason he said 97 octane could be that they still have winter blend being in Ohio which is close to 70% ethanol. right now in Mich. they have stickers that says "might contain as low as 70% ethanol" and then it says 105 oct. which i would believe is E85's rating.
 
twinrats said:
Just did a quick yahoo search of E100 (100% Ethanol) and found it is 106 octane...so 105 octane for 85% sounds too high..if it's mixed 50% with 87 octane regular gas that would come out to 96.5 octane blend, the Winter 70% blend should come out to 98.4 based on percentages, still good but way off of 105!
Click to expand...

No way in hell is E100 106 octane. It's closer to 115.
 
twinrats said:
I git the 106 octane from a article on a Saab prototype car made to run on E100. The article is from Greencar.com. Here's the link:

Saab BioPower 100 Concept E100 Ethanol Vehicle | Green Car .com

I'm no expert on Bio Fuels but one would think GREENCAR.com is.
Click to expand...

Yes, they are experts, but what you're not taking in to consideration is that the Saab is a European car. I'm positive the article is written with this in mind considering the USA and Europe rate their fuels differently. Case in point:

Octane rating - Wikipedia, the free encyclopedia

Therefore, E100 is 116 octane.
 
MrMNTTA said:
Yes, they are experts, but what you're not taking in to consideration is that the Saab is a European car. I'm positive the article is written with this in mind considering the USA and Europe rate their fuels differently. Case in point:

Octane rating - Wikipedia, the free encyclopedia

Therefore, E100 is 116 octane.
Click to expand...
Good point...except according to the link you provided the EUROs use the RON rating which is usually 4-5 points higher than or average of the RON and MON average which we use here in the states. I have pasted a section of your link that describes this:

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).
 
Come on dude, pay attention.

[edit] Examples of octane ratings
The octane ratings of n-heptane and iso-octane are respectively exactly 0 and 100, by definition. For some other hydrocarbons, the following table[2][3] gives the 'AKI' (AKI=avg of RON & MON) ratings.

n-octane -10
n-heptane 0
2-methylheptane 23
n-hexane 25
2-methylhexane 44
Hydrogen* >50
1-heptene 60
n-pentane 62
1-pentene 84
n-butane 91
cyclohexane 97
iso-octane 100
benzene 101
E85 Ethanol 105
Methane 107
Ethane 108
Methanol 113
Toluene 114
Ethanol 116
Xylene 117

Next time, read it all.
 
MrMNTTA said:
Yes, they are experts, but what you're not taking in to consideration is that the Saab is a European car. I'm positive the article is written with this in mind considering the USA and Europe rate their fuels differently. Case in point:

Octane rating - Wikipedia, the free encyclopedia

Therefore, E100 is 116 octane.
Click to expand...


+1

In regards to E-85 you must remember that it will perform better than a 105 octane fuel. Octane is NOT everything when you are dealing with alcohol based fuels.
 
If it isnt knocking at 30psi who gives a f uck what the octane rating is:tongue: .
 
Hey BISON....COOL DOWN I'm just trying to get the correct info on the E85....NO NEED TO BE DROPPING F BOMBS.
 
hell right now I'm running closer to E-65 or so with the 87 I've mixed in and and I can still runn 22psi @ 26 degrees.. :)
Thats with a stock turbo and intecooler, etc.....
 
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