Much of the country has been buying E10 for the last 3 years. While it could be new to your area if you're outside a non-attainment area that didn't use RFG, I read your post and I'm thinking, where's this guy been for the last three years?

Just as there were no signs or other indicia when the oil industry started using MTBE to meet RFG requirements under the Oxyfuel requirements in 1993, and the Reformulated Gas program in 1995 -- there's been little to no signage or fanfare when the industry switched to ethanol from MTBE starting in 2003 when CA banned MTBE and 2004 when NY banned MTBE. The 2005 energy act eliminated the need for the use of an oxygenate in reformulated gasoline, but it also has a provision for renewable fuels, and so ethanol and biodiesel will be used in greater quantities going into the future.

On balance, while ethanol has gotten a lot of negative publicity recently, burning ethanol is overall better for our energy independence and our environment than burning gasoline. People often don't realize that ethanol has an octane rating of about 110 and never think about things like "alcohol burning funny cars" or other high-performance ethanol applications. In fact, for 50 years the oil industry has been using ethanol to boost octane, often in premium grades of gasoline.

And just to be clear: ethanol is alcohol. The same alcohol that you drink (think: Jack Daniels, Everclear, the 12% alcohol in your Merlot), except they mix it with gasoline so people won't drink it. That is what it means when they say its "denatured."

There is less energy content in ethanol, though, that is true, and so you can expect a slight drop in mileage. I would guess the huge decline you're seeing is more due to cold weather (which always drops mileage) than it is the ethanol.

While you might feel they're doing something devious to you, I hate to break this to you: there's 140 refineries in this country for all 300 million of us. The gas you get at two different branded stations in your area likely came from the same refinery, even if one's an ExxonMobil station and one's a ConcoPhillips station. Gasoline is pretty fungible. Except for the proprietary detergents and additives they put in premium gas, it's basically all the same in a given distribution area.

So what are your damages? It's not as if one company is selling you ethanol, and you're getting ripped off at one station but not others. How much money have you lost, because of it? I'll give you a clue: even accumulated over three years, it probably wouldn't pay for an hour's legal consultation about it.