Nooooo! Your heart sinks. You've just realised you've put petrol in your diesel car. What on earth do you do now?
- First things first... Don't start the engine! If the wrong fuel is only in the tank it's much easier to prevent any damage to the engine
- Get help to push your car to a safe place where it can be drained - some breakdown organisations will drain your fuel tank on the petrol forecourt
- Call your car insurance provider... They may provide cover that pays for the cost of draining your fuel tank or repairing your engine
What is misfuelling?Misfuelling is simply putting the wrong type of fuel in your fuel tank. So if you drive a diesel car and you fill it up with unleaded – that's misfuelling.
You might be thinking that it's just not possible to put the wrong fuel in your car these days. The nozzles are different shapes aren't they?
Well, it's certainly more difficult, but not impossible to put diesel in a petrol car. The nozzle on a diesel pump is bigger and therefore won't fit in the neck of a petrol tank smoothly. However, it's much easier to accidentally put petrol in a diesel car.
The petrol nozzle is smaller and fits into the diesel tank easily. It's only when you realise you're holding a green pump not a black one that the penny drops.
What can misfuelling do to your car?Putting petrol in a diesel car causes all sorts of problems. Diesel acts as a lubricant, making the engine and its components run smoothly.
Petrol acts as a solvent, so it prevents the lubricating action of the diesel. This means that the fuel pump runs without lubrication, so its components rub together, grinding off small fragments of metal called 'swarf'.
These fragments can travel towards the fuel injectors and clog up the holes in the injectors. This stops the fuel reaching the engine and eventually the car judders to a halt.
On the way to the fuel injectors, the petrol can also corrode the seals on the fuel lines that carry the fuel from the tank to the engine and can contaminate the fuel filter.
If the petrol reaches the fuel injectors and they need replacing, together with the fuel pump, fuel lines and fuel filter, it can become a very expensive repair job.
Five golden rules if you misfuel
Don't drive off. If you realise your mistake at the petrol station, don't start the engine. This begins the sequence of events that cause maximum damage to your engine.
Do inform the garage attendant. Explain what's happened – it's quite likely they have dealt with this problem before.
Do get help to push your car to a safe place where it can be drained. Some breakdown organisations will drain your fuel tank on the petrol forecourt.
Do call your car insurance provider. They may provide cover that pays for the cost of draining your fuel tank or repairing your engine. Call them first as they may have a procedure they need you to follow to get the repairs sorted out.
Don't just keep going. If you've already left the petrol station before you realise your mistake, don't keep going until the car breaks down. Pull over somewhere safe and call your insurance provider or a breakdown organisation.
Accidentally filled your car with the wrong fuel? It happens. We pay to drain and flush your fuel tank, as well as cover the damage to the car's engine*
*If you accidentally use E10 rather than E5 there’s no need to drain the tank, just fill with E5 next time.
What is E10 fuel?
You may have heard that the UK is currently transitioning away from standard E5 fuels to eco-friendlier E10 fuel. This may sound complicated, but don’t worry! E10 fuel is simply fuel with a 10% rather than a 5% ethanol content, meaning less CO2 emissions. Hooray!
Can I use E10 fuel in my car?
Is there a chance you could be misfuelling if you put in E10? Luckily, the answer to this is almost always no. All cars produced after 2011 should be E10 fuel compatible. The government has even set up a website where you can double check whether or not your car can take E10 fuel, so if you are unsure, you can always check there.
Can I top up with E10 if there's other petrol in my tank?
When it comes to mixing E10 fuel with the regular unleaded petrol that you usually use, that’s not a big problem either. In fact, if you’re driving an older car and accidentally fill up with E10, you can simply top it up with E5 as soon as you can once you’ve used up a third of the tank.
Are you covered by your insurance?You can find out if you're covered by your car insurance by reading the policy details. Misfuelling will probably be mentioned under accidental damage.
If your insurance policy doesn't cover misfuelling, it should have an exclusion clause that specifically excludes making a claim for misfuelling.
LV= provide cover not only for draining and flushing your fuel tank, but also for damage to your car engine caused by the wrong fuel.
You can find out if you're covered by your car insurance by reading the policy details.
Ways to prevent misfuelling
Accidents happen but there are a few things you can do to make sure you don't put the wrong fuel in your car:
- Put a sticker with the name of the fuel inside the fuel cap
- Always read the label on the pump
- Do a double check to make sure the labels on the fuel cap and the pump match
- If you change between cars with different fuel types consider installing a device to prevent misfuelling
- Try to eliminate distractions when you get to the pump