That moment, when the penny drops that you have put the wrong fuel in your vehicle. Whether you are still standing at the pump or are driving the vehicle after filling up, UK DPF have listed what needs to be done.

It is easier than you think to fill with the wrong fuel, over 150,000 drivers in the UK make the same mistake.

If you are driving after filling the vehicle, there are some obvious signs that indicate that you may have added the wrong fuel:

  • Slower acceleration
  • A knocking noise when accelerating
  • Smoke emitting from the exhaust
  • The vehicle cuts out and jumps
  • Reluctance for the vehicle to restart
  • The engine warning light comes on

It is important that you do not drive the car as soon as you realise the error.

If you have just filled up and are still at the pump:

  • Do not start the vehicle
  • Tell the staff at the service station what has happened
  • Put the car in neutral and push away to a safe place
  • Contact your insurer, as some policies will cover flushing

If you have started the vehicle or driven it:

  • Turn off the engine as soon as you are safely able to do so
  • Select neutral
  • Contact a fuel flushing company to remedy the issue
  • Contact your insurer as soon as possible

What does the wrong fuel do to a vehicle?

Adding diesel to a petrol vehicle causes less damage than petrol being added to a diesel engine. However, both scenarios can be expensive to rectify if a vehicle is driven and the fuel has entered the engine.

Diesel in a petrol vehicle:

Diesel will coat all the parts of the fuel system; this is likely to cause misfiring of the spark plugs. Smoke from the exhaust and engine cutouts are an obvious sign of this. It is important to flush this out as a matter of urgency.

Petrol in a Diesel Vehicle:

Petrol is a solvent and will quickly strip off and remove all the special lubricants required in a diesel vehicle. This is bad news for a diesel engine as it requires these lubricants to make the engine run efficiently, smoothly and without friction. The loss of lubrication can cause a lot of damage to many components. This can result in very expensive repairs and possibly the necessity to replace the whole fuel system. A fuel flushing company should be contacted immediately.

Is misfuelling covered under my car insurance policy?

Misfuelling is covered by some insurance companies, it may be included under the accidental damage part of your policy. If it is not included, some insurance providers may allow you to add this to your current policy at an added cost.

How long does fuel flushing take?

Many fuel flushing companies run a 24/7 service; most will be able to get to you within 1-2 hours. Flushing generally takes under an hour and is done in situ.

Should I have the vehicle checked by a motor mechanic?

It is advisable to have your vehicle inspected by a qualified motor mechanic after adding the wrong fuel. If the ignition has not been turned on, chances are the fuel has just remained in the tank and flushing will be all that is needed. If the car has been started the wrong fuel would have entered the whole system, therefore it really should be checked over by a mechanic for any possible damage. Driving the vehicle with damaged components could lead to further damage and a larger repair cost.