I have a flex fuel tune. Tuned for 93 and E85.The ECU will adjust the map depending on which fuel is being used. I don’t have to do anything or switch between fuels when driving etc… Just because your are buying “E85” at the pump doesn’t mean you are getting 85 ethanol. I made a post about this recently. See below. Something to be aware of is you’ll use about 30%+ more E85 then pump gas when driving. Cheaper per gallon but you will be filling up more often. So not really any cheaper. There is a good write up about it on z shack. It’s on the NA-TT tech halfway thru article https://www.zshackperformance.com/blogs/news/in-depth-guide-to-turboing-your-na-compression-vg30de-motor-300zx
  ` 1990 NA 1993 TT |