Tests of E20 in Australia and other countries show massive destruction vs even E10.
http://www.environment.gov.au/....html
"Upon introducing these vehicles to a 20% ethanol blend, these deposits are likely be stripped away causing fuel filter blockages and plugging of fuel metering components.
Perishing and swelling of elastomeric and plastic materials making up the fuel system is highly likely on the older vehicle fleet when exposed to E20. The newer fleet may be less likely to show these problems as many of the components are globally sourced and therefore may be compatible with up to 10% ethanol blends providing some element of protection for an E20 blend"