What is the octane rating of 180 proof ethanol?
A. 180 proof ethanol is equivalent to 106 octane. You would need to modify your engine to run a fuel that is 90% alcohol and 10% water. This involves carburation (or fuel injection) and timing. But if you buy or own an E85 car, these adjustments are done automatically, due to a new computer chip and Oxygen sensor in the fuel line. Q. What engine modifications are required? Perhaps none at all–the car you drive may already be factory-ready for E-85 (85% ethanol) which you can make yourself. A. In the old days (pre-1990), engines had carbeurators, and you had to drill out the jets or install larger jets. Go to my page, “Converting your engine” for instructions on how to do that. We are setting up a network via this website to get new computer chips made for cars that need them, and a list of cars that already have the right chips. (These computer chips adjust the fuel injection and timing accoring to an O2 sensor that tells it what fuel blend you are using. If you change the chip (a qui
