I’ve put the wrong fuel in my car: what to do now

If you realise you have put the wrong fuel in the car, do not start the engine and tell the forecourt attendant straight away. If the car is already running, stop as soon as it is safe, switch it off and do not restart it. Call breakdown assistance; do not try to drain or correct the fuel in the tank yourself.

If you have not started the car yet

After filling up, if you notice that the pump does not match the fuel specified for your vehicle, do not put the key in the ignition or press the start button. Tell the forecourt staff what fuel you put in, roughly how much, and when it happened.

Do not try to dilute the wrong fuel by adding the correct one, even if you have only put in a small amount. The right response depends on the engine, the amount of fuel, the fuel system and the car’s condition. Let the attendant make the area safe and call for assistance to assess the situation and take the car to a garage.

If you have already started the engine

If the vehicle is moving, stop as soon as you can without putting traffic at risk. Use your hazard warning lights if necessary, move to a safe place, switch off the engine and do not restart it. Do not try to drive home or to a garage: the fuel may already have entered the system.

Call breakdown assistance and tell them which fuel was put in, how much, and how long the engine was running. If the car is leaking fluid, producing smoke or showing other symptoms, move away when it is safe and follow the responders’ instructions. For immediate danger, call the emergency services.

Leave the repair to professionals

Draining the fuel and checking the tank, pipes and engine should be assessed by a garage or specialist service. Ask for a record of the work carried out, and keep the receipt and breakdown details for your insurer or hire company, if applicable.

After the repair, before driving again, check that the vehicle is not showing any warnings and ask whether you need to observe any restrictions. Do not use additives, household vacuum cleaners or improvised containers: fuel is flammable and its vapours can be dangerous. To avoid this happening again, check the label and pump before every fill-up.

You can revise driving theory with Quiz Patente Ufficiale, which offers topic-based study, exam quizzes and a review of your mistakes.