alt Hacker NewsSorry but this is complete horseshit. Ethanol is corrosive to engine and fuel system components. It is also hygroscopic and will suck water in which is bad news for your fuel system. The less the better. There is a reason modern cars will tolerate up to 15%. With modern DI engines you are getting buildup no matter what and it is completely unrelated to the presence of ethanol in the fuel. Ask any BMW owner and the fuckin' spa treatments they need to take their engines to.
Flex-fuel vehicles run on E85 are required to run a tank of regular gas every few months per the manufacturer. Which is literally the opposite of what you are suggesting.
I grew up in Brazil, where we had a very successful program for cars running on ethanol fuel with a little gasoline added. It was common to have certain models of car be offered as gasoline or ethanol (back then engines needed to be tuned for one) powered.
At least one car magazine would buy retail cars and fully disassemble them for analysis a year later. The difference between a gas and an ethanol engine was quite shocking - the ethanol engine was always clean and displayed less wear than the gas version of the same engine. Part measurement indicated no significant difference in wear between the engines. There were models only offered with ethanol engines because they offered a little more power because of higher compression rate.