The Delicious Tuning FlexFuel kit for EcuTek 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 (if applicable) and more based on the ethanol content.