BS..read your owners manual... unless you have "flex-fuel" vehicle, using any ethanol blend higher than 10% invalidates the warranty and can cause serious damage to your engine and fuel system. Small engines like in lawn mowers and especially boat motors can be totally wrecked by using a single tank full of ethanol blended gasoline. Corn ethanol is a boondoggle that enriches corn farmers and ethanol producers and does not reduce the consumption of oil. It would be cheaper to just write corn farmers a government check for producing corn than to support this bio-fuel boondoggle.
I think Briggs & Stratton and anyone else that manufactures small engines should have a big sticker on the fuel tank warning the buyer about gasoline with ethanol. When I figured out why my mowers ran so badly I have used nothing but ethanol-free including in my vehicles.
There's a web site listing all the ethanol-free stations in the U.S. and Canada: