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      08-31-2012, 01:03 PM   #65
MDORPHN
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Quote:
Originally Posted by vasillalov View Post
Well not exactly. Resistance to detonation = AKI -> Anti-knock index. So that's your unit of measurement.

Yes, E85 has additional benefits when it comes to cooling the combustion chamber, but technically, that's different than anti-knock index.

Plain and simple:

USA 91 fuel = 91 AKI
USA 93 fuel = 93 AKI
USA E85 = 94-96 AKI
PURE ETHANOL = 99.15 AKI

Source: http://en.wikipedia.org/wiki/Octane_rating

Do not confuse E85 and pure ethanol. Totally different things.


EDIT:

Take a look here:

http://en.wikipedia.org/wiki/E85

Second paragraph in Octane and Performance Section:


So guys, stop propagating a lie! E85 does NOT have such a high octane rating as you think it does.
Accusing folks of "propagating a lie" does not encourage informed discussion of any topic, but.... the subject of ethanol's "effective octane" (which is far higher than you suggest), at least in a direct injection motor, is far more complicated.

Take a look at these articles:

http://web.mit.edu/mitei/lfee/progra...2008-01-rp.pdf

http://web.mit.edu/mitei/lfee/progra...2008-01-rp.pdf

dspace.mit.edu/bitstream/handle/1721.1/69496/775670245.pdf

Neil