What to Do When You Use the Wrong Fuel at the Petrol Station

Feb 12, 2024

We all know that sinking feeling when you put the wrong fuel in your car at the petrol station. But hold up, it may not be such a disaster as you think - your car will not necessarily break, you just need to keep calm and follow the steps below.

But first, let’s do a quick review of why the wrong fuel might break your car:

Why would a car break down if it’s had the wrong fuel?

The main problem is that adding petrol to a diesel vehicle, or vice versa, is likely to cause problems for the engine:

• It may stall or may not start at all - as the mismatched fuels have different combustion properties.
• The wrong fuel might damage fuel system components which simply weren’t designed for that type of fuel. For example, your fuel injectors, seals, and fuel lines may be affected.
• Catalytic converters and sensors will get fouled up by the wrong fuel mixture.
• The wrong fuel might also cause misfiring and poor acceleration so these are things to look out for.

The extent of damage depends how much fuel went in and crucially how quickly the problem was resolved - especially whether it was resolved before the engine was turned on.

5 things to do once you’ve realised you’ve used the wrong fuel

First, and we can’t stress this enough, don’t start the engine if you've added the incorrect fuel. Running it will exacerbate the issue. Here are the best steps to take:

1. Stay calm and stop adding fuel.

Though upsetting, this can be resolved so don’t worry - just stay calm. Stop adding fuel ASAP and avoid turning the key or hitting the start button at all costs.

2. Call a station attendant

Trust me, they will see this all the time. They’ll be able to help push your car to a new, safe spot if required and they may have a phone if you don’t. If moving the car, just unlock the steering - do not turn the engine fully on.

3. Call your breakdown service

Make a call to your breakdown service - if you aren’t covered for misfuelling, the station attendant may be able to help or have a quick google. You’ll find providers nearby who deal with misfuelling.

4. Drain and flush the tank

This may happen in-situ if your car is in an appropriate position, or your car may need to be towed. Provided you haven’t driven anywhere and there is no damage to any internal parts, this should take under an hour. The system will be fully drained and flushed and some fuel additives may be needed to help clean internal components.

5. Fuel up and get on your way

Phew, that was a good save. You should now be fine to add the right fuel to your vehicle and get driving again.

Wrapping It Up

It might seem like a nightmare to use the wrong fuel in your car - and while it is stressful, you can reduce the potential negative outcomes by working through these steps methodically. Prioritise keeping your engine off and get some professional help and you’ll be on your way in no time.

If you’d like to keep improving your car know-how, take a look at our handy guides on what to do if your car won’t start and what to consider before buying a new car.