I think it depends on the e85 source as well. gas station e85 is not as good as say Rocket brand e85 so people who run true e85 from rocket or sunoco may not have issues since they wont have all the additives and junk in it that CA makes companies put in fuels. Our e85 is usually no more than e78 anyway. I never saw it ever go higher in 2 years of running it from Propel or Conserve fuels brands. WHo knows what they put in it.