the drop in mpg is coming!!

Guy's I'm afraid your numbers are wrong. 10% ETH on average will result in approx a 3% reduction in mileage. There are other factors, ETH is HIGH octane, so it can be blended with more available low octane fuel to boost the octane to 87. 87 octane is 87 octane.
I believe we are hopefully in the middle of a transition, flex fuel is inefficient. If an engine is designed fro the onset to burn ETH rich fuel, it works a lot better than a gasoline engine modified to burn ETH rich fuel.
If you guy's want to go on a crusade, find out why SUV's are exempt from the "Gas Guzzler tax" You have a chance there maybe.

 

Luckily that is not true. 10% ethanol = 3-4% less mpg. People who say higher are not accounting for colder winter temperatures or other factors.

I am not for ethanol, its energy return is not good enough. If it was made from waste (like corn husks etc) then it would be more workable. It could also be manufactured using waste heat from an industrial process instead of burning natural gas but currently it is not.

 

It is time to be heretical on Prius chat again. Sigh.

Using Alcohol lowers your MPG, as it has 30% less energy than gasoline.

Now lets ask our selves, what horrible happens if you have less MPGs?

You have to fill up more often.
If you have a Prius, your bragging rights may be reduced.
That's it.

E10 gasoline is cheaper than pure gas, E85 is WAY cheaper than pure gas.

If you get 3% worse MPG on E10, but pay 5% less money, you cost per mile is better even of your MPG is worse. If you used 90% of the gas to go 97% of the distance, you used less petroleum.

If you get 30% worse MPG on E85, but pay 45% less money, you cost per mile is better even of your MPG is worse. If you use 15% of the gas to go 70% of the distance, you used less petroleum.

(I am fully aware that no Prius is FlexFuel ready, yet. Prius owners should not use E85. I mention E85 as even normal owners can feel a 30% drop in fuel mileage, while only hybrid owners are keeping such accurate track that they notice 3%)

 

I started about a month ago and will be permanent. Earlier this summer we had "normal" gas.

 

back in the late 70's some predicted that we would run out of oil by 1992

 

The MPG hit the OP is talking about is most likely cold-related rather than due to more ethanol in the gasoline. If NY has 10% ethanol all year round, the winter blend will be no much different from summer gasoline since more than 10% ethanol is NOT allowed in any US gasoline.

The 3% MPG hit of E10 compared to pure gasoline is what the theory says but that hit will depend on the type of engine. In Brazil, my brother has demonstrated (using a 2.0l flex engine) in his tests that the MPG hit is more than just 3%, more likely around 6-7%, but someone needs to run similar tests on the Prius to find out what the real number is.

Corn ethanol is not a good alternative fuel in the US. It is pretty much well accepted worldwide that the only place ethanol has worked and continue to work greatly as a viable fuel source is in Brazil, from sugar-cane. Gasoline and natural gas have become alternative fuels in Brazil since ethanol is now predominant, even motorcycles are using it. Brazil is foreign-oil free, as the gasoline used there comes from its own sea-derived oil reserves.

Sugar cane in Brazil generates lots of jobs for farm workers in the plantations, lots of industrial jobs in the ethanol distilleries, and residual cane-waste for feedstock. So, really, a neat job by Brazilians, besides, of course, beating Chicago for the 2016 Olympics!