so i now run 92 just so my car runs good and smoother i think its bull ****e that we dont have a choice if we want to run that crap in or car or not which i would chose not,i really dont think 10% is going to save the earth.

 

The main reason they use the ethanol isnt for a octane boost its to oxygenate the fuel to meet epa requirements they used MTBE before and some still do. In another words your 92 probably has near the same ethanol content at the 93.

 

As GRIFF said, the EPA mandated oxygenated fuel to cut down on smog. MTBE (methyl tertiary-butyl ether)was the mandated additive. However; a few years later it was found out that MTBE contaminated ground water and very bad for health. Several states were ready to sue the EPA, and the EPA said they still needed to oxygenate the fuel, but instead of MTBE they allowed 10% ethanol. The same 10% ethanol was added to all grades of fuel, 87, 89, 93 & up to 94 on the East coast. At first ethanol was only added in the winter months, and you could detect the loss of power (because the engines were not tuned for it)and increased fuel consumption. Now ethanol is added year round so nobody really notices because there is nothing to compare it with.