Bonneville America Forums Forums Technical Forums Performance Mods Ethanol in gas =poor performance?

Definitely decreases gas mileage. I was getting over 140 miles until hitting reserve on regular ethanol free fuel. (Didn't know it was ethanol free at the time because I didn't know any stations around here used ethanol.) A few weeks ago my mileage suddenly dropped to about 118 on two consecutive tanks of gas. First one I thought maybe I was a little heavier than normal on the throttle. Second tank same thing happened. At the time stations in Oklahoma weren't required to notify their customers if there was ethanol in the fuel. As of this past Monday it became mandatory. Well I searched around until I found a station that had the ethanol free fuel. Mileage is now back up. It costs about 10 cents a gallon more for the ethanol free here; however, it is worth it for the increase in mileage.