When the auto manufacturers themselves go to the effort to issue warning stickers and owner manual guidance to not use E15 (Ethanol 15%) on the pain of voided warranties (Toyota), I presume that they might know their own engines. This is from AAA on this subject; "The auto industry, though, says E-15 -- as the blend is known -- corrodes pumps, fuel lines and injectors. And manufacturers say they won't cover damages caused by the higher blend."
As for older vehicles, designed and built to non-ethanol standards, the alcohol concentration is a known deteriorating factor for the fuel systems. Perhaps it is excessive to say that E15 is a killer but I would not want the expense of parts replacements!
My ‘95 Nissan Maxima had to have all its fuel injectors replaced after 3 years. The mechanic told me they were corroded by ethanol use. I still drive it today with the replacement injectors and it runs like a dream. And I haven’t used ethanol since they were replaced.
Gimme straight gasoline please.
I will concede that it attracts water and causes corrosion, and it may well, in higher concentrations, attack rubbers and plastics which are part of the fuel system. The fuel rail and injectors are about the only thing that could fairly be considered an actual part of the engine.
Brazil built cars that ran on pure alcohol, and there are cars built here called "Flex-fuel" vehicles, which can run on various blends. When Brazil discovered they were awash in petroleum...they backed off the ethanol.