Takes all the guess work out of determining what the ethanol/gasoline (petrol) ratio is in your vehicle. Our FlexFuel system determines the content ratio between gasoline and ethanol content in the fuel. It then sends a signal to the ECU which dynamically computes the correct air/fuel ratios, ignition timing values, boost levels, cam angles, traction control and more based on the ethanol content. Confused about E85 ethanol and Flexfuel? Visit our FAQ.