I've been gathering infos here and there for a few months now especially in a few threads i made however i'm still trying to understand how E85 and E100 impacts oil. Most of the information i found is pre 2011, before the API SN spec and i think that's the reason why flexfuel cars owner's manuals say to cut OCIs in half. On top of my newbie's head, fuel dilution could be a concern since way more fuel is dumped in but on the other hand, oil stays cleaner since there's far less soot/carbon contamination. As an exemple, in my car the oil stays cleaner but mileage went from 36 mpg on regular gas and highway driving to 23 mpg on E85 for the shorter distances i currently do, it obviously has an impact on how often i should change the oil. Are OCIs different if the car is run on E85/E100 vs gas in Brazil? Brazil had ethanol decades before the SN spec. Please avoid any uneducated "ethanol is corrosive, it eats up rubber and aluminium and will require 2k oil changes" etc. I'm after facts, all kinds of UOA from everywhere around the world as well as translated studies written in portuguese, swedish etc are welcome.