If you are still at the service station where the mistake was made then it is unlikely that any damage will have taken place as long as the engine hasn't been started. We can drain and flush the system to get you on your way again. If the car has been driven, there could already be damage caused. In this case please call us for more information. However we have successfully drained and started over 99% off all vehicles driven on the wrong fuel - so chances are, we will get you going again.