Here in Texas, if > 1% of the gas is ethanol, there has to be a sticker on the pump. The last couple tanks I've gotten have been E10 (likely since the sticker has said "up to 10%" and given the price of oil they likely are using as much corn as possible )

Today I filled up at a station that did not have the sticker and within 5 miles I could FEEL a difference in the car. It felt significanly smoother in the upper power band and I felt like I was lugging around 500lbs less weight.

Has anyone else experienced this and/or run any true tests on the effect of ethanol on the X?

 

We have E10 here almost exclusively now. My car loves it and runs awesome.

 

What's the temperature there? We're nearing/breaking 100 every day with moderate to high humidity. I know that ethanol = cooler burning but less power/volume, so maybe that combined with the hot sticky air = bad combination?

 

Where in Texas is Frisco located? Some of the panhandle only gets 90 octane! If you get 93 octane, you should not see a problem from fuel quality, rather the crappy stock mapping.

Its mid nineties here and very high humidity also. My car is custom EcuTeK tuned, though, so that's a huge reason it runs well.

When in doubt, always use a top tier station like Shell, Exxon, Chevron, Phillips66, 76, etc. Those are stations that use good gas.

 

Frisco is a burb of Dallas. It's 93 at most stations.

I've been using "good" gas (although I can't get my wife to quit buying gas at Kroger, sigh) and my car has always felt sluggish compared to the demo car at Don Herring's. I filled up today where they fill the demo car up and now my car has the zoom-zoom

Placebo effect? Who knows, but there is a definite increase in pull...