there are several vendors that make a flex fuel sensor kit. it will measure the amount of ethanol and adjust the tune. this does require a good kit and a good tuner. I have it on my GTR and it works flawlessly. I can toggle a switch on my car and see the exact amount of E in the car. I do run a tank of 93 through it every2-3 tanks to help keep the fuel pumps clean so it is required to have the fuel sensor kit. Visconti and Got Boost make good kits for the GTR. Assume they would work on other cars as well. My tuner told me that anything above 20% ethanol will start to give you an advantage over pump gas assuming the tune adjust for the increased content.