i'll try not to get political here, but, the E15 was pushed by one of the representatives from the mid-west. Of course this is corn country. Apparently he got it passed with the promise of cleaner air, etc.
I buy non ethanol gas. true, it's hard to find and it costs more, but, well worth it. My truck has a Hemi and my gas milage did improve and i can tell the truck runs better ( more responsive) Hopefully, all my yard equipment will last much longer using non-ethanol gas.
If you can, avoid the E15 at all costs, it will ruin everything you use it in. It won't give you better gas milage, you will use more fuel, it doesn't "clean the air".