What to Do If You’ve Misfuelled Your Diesel Car with Petrol

car fuel

Accidentally filling your car with the wrong fuel type is a surprisingly common mistake. The AA estimates that every year, around 130,000 drivers make this mistake. And unfortunately, while the problem can happen frequently, the consequences can be devastating.

Today, we want to delve into the problems that can follow a car misfuel, specifically with petrol gas in a diesel car, along with what you should do if it ever happens:

The Problem of Putting Petrol in a Diesel Car

When petrol is put in a diesel car, it can cause several problems.

The most obvious issue is that the petrol will not combust properly in the diesel engine, resulting in poor performance and decreased fuel efficiency. This is because petrol and diesel have different combustion characteristics and cannot be used interchangeably.

The second issue is that petrol can damage the diesel engine’s fuel injectors and other components. Petrol is much more volatile than diesel, so when it is put into a diesel engine, it can corrode the fuel injectors and other components, leading to expensive repairs.

In addition, petrol can also damage the diesel fuel filter. Petrol is much lighter than diesel, so it can pass through the diesel fuel filter, resulting in a clogged filter and engine, all of which can reduce the engine’s performance and lifespan.

Finally, petrol can damage the catalytic converter of a diesel car. The catalytic converter is designed to reduce emissions from the exhaust, and petrol can damage the converter, reducing its effectiveness.

What You Should Do If a Car Misfuel Occurs

The first thing to do if your car has been misfueled is to avoid starting it. Starting a misfueled engine can cause serious damage and can even lead to a breakdown. Even if the engine starts, it is best to stop it immediately and call for help. But of course, at this point, if you haven’t started the car, you need to get it out of the way for other people to come and fuel their vehicle. Be sure to reach out to the station’s staff to help move the car out of the way.

Once you and your car are safely out of harm’s way, phone your insurance provider, given you have the policy to cover misfuelling. If they do, they’ll send over help. They will also cover some costs. If you do not have an insurance provider, you should call a breakdown provider to send roadside assistance and recovery.

On that note, if you did start your car, you must pull over as soon as possible and stop the car to limit the damage the fuel can do. After that, call your insurance provider or breakdown provider for help.


While misfuelling is certainly a problem that can easily be provided, quick thinking must be done to ensure it doesn’t damage your car. If you’ve misfuelled your vehicle, follow the tips above. Additionally, once the ordeal is over, or you just want to avoid ever experiencing this, be sure to implement ways to help you remember what to fuel. For instance, you can put a sticker on your gas cap reminding you of the right fuel. That way, you can drive around and fuel up your vehicle without too much worry!

Fuel Fixer offers mobile units across the UK to help with misfuelling issues. If you need to remove petrol in a diesel car, contact us right away.

Leave a Comment

Your email address will not be published. Required fields are marked *