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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,267
Originally Posted by mark houghton View Post
Today I filled her to the brim with Exon premium 92 which claimed no ethanol added. Nothing but the straight stuff. Also added an alloquat of Stabil 'cause my intentions are to put her in storage here shortly. I chose the straight stuff because of ethanol's affinity to attract moisture....not a good thing in storage conditions.

But, not after at least one (or two) more good rides. What I noticed is that my AFR's at cruise seemed about 0.2-0.4 lower than what I normally experience with 10%ETOH blends. Could be the Stabil, could be the "real" gas. Comments? Car ran like a raped ape regardless, especially with the cool mornings.
The ethanol molecule in E10 gas has oxygen in it. Mixing alcohol with gas will always lean out the mixture compared to real gas because the alcohol is carrying in some oxygen with it.
As an example fill up with E85 gas and you'll be way lean.
The reason our cars idle smoother and better around 13.5:1 instead of 14.7:1 is partly because most pump gas is E10 and the stoich mixture is lower than 14.7 nowadays.
Old 10-12-2011, 06:22 PM
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