Sorry I haven't responded earlier - work, it's a killer!
The amount of Ethanol in the gasoline we purchase today will not do any harm to your engine. The lousy mileage you experienced is normal. BUT, whether or not you have Ethanol in your mix depends on whether or not the price of Ethanol is less than the bulk price of the gas your gas station purchases. If the cost is less than gas, you have Ethanol in the mix, if not, you don't. Ethanol prices vary just like gasoline & it is produced locally. Since there are no distribution pipelines for Ethanol it has to be transported by diesel eating tankers. Ethanol cannot be pumped through the same pipelines as gasoline, the lines will be destroyed.
At least here in WI the amount of Ethanol in the gas is limited by law, 10% is the max you can mix with gas here in Cheeseland. A few stations do not mix Ethanol with premium; if you're really concerned you can try asking the attendant though he or she may not know.
Bottom line, I wouldn't lose any sleep over the mix. At least here in the Heartland it's here to stay.......well, unless our politicians can begin to see that it's certainly NOT the answer to our fuel woes. I doubt if the farm lobby will let them.
As to the PM guys: they were the days indeed! They don't make music like they used to !