Sounds great that they cost 7.2 cents less, but factor in the decreased fuel economy and on many vehicles it will actually cost more. Tests vary (the ethonal sponsored ones even admit to a 1/2 MPG drop and those are qustionable due to the source. Most studies I read vary from 2-10% loss on E10.
Based on my own experience it's a big no it doesn't save anything at 10 cents (the difference here in Iowa). My Fusion losses 2 MPG on E10, my old Taurus work car lost 1 MPG and the company Explorer I had lost 3 (wich I attribute to the fact that it was an E-85 FFV and was compensating for the 10% ethanol content by running richer)
I suggest everyone try 2 tanks of each (checking the mileage on the second tank after adapative strategy has had enough time to adjust to octance and other differences) and see what you fuel economy does. 90% of the people I convince to try this end up choosing to pay the extra 10 cents to get straight gasoline
I'd really like to see E10 eliminated, Make E85 available, but lets not have 7 different choices, 100% gasoline or E85 (and have it readiliy available which eliminating E10 would accomplish by freeing up ethanol and gas pumps both)
http://www.dailygazette.com/news/200.../0203_Ethanol/