Is misfuelling covered by car insurance?

Putting the wrong fuel in your car is a common but expensive mistake to make. Find out whether car insurance could help cover the cost.

Eve Powell
Eve Powell
Updated 20 June 2023  | 4 mins read
Reviewed by Jasmine Hembury

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What is misfuelling?

Misfuelling means putting the wrong type of fuel into your car. This typically happens when you’re not paying attention at the petrol pump.

Figures from the RAC suggest that around 150,000 UK drivers make this potentially expensive mistake every year.

It normally involves diesel cars being filled with petrol, which causes more serious damage. Petrol cars aren’t often affected because the bigger diesel nozzles don’t usually fit.

What is misfuelling cover on car insurance, and why is it important?

Misfuelling cover isn’t often found as a standard feature of car insurance – out of 325 comprehensive car insurance policies on Defaqto, only 14% cover misfuelling as standard.
Only 2% of the policies could provide misfuelling cover as an optional extra, so you might not be able to add it to your cover, even if you want to..

If you’re covered, it could pay for the cost of draining and flushing your tank. Some policies may also cover the cost of repairs needed because of misfuelling, but it’s important to check and make sure.

According to the RAC, the wrong fuel is put into cars in the UK around once every three minutes. But unfortunately, the cost to drain petrol, make repairs, and replace fuel could add up to as much as £5,000 in extreme cases.

The right cover could help to pay for this potentially expensive mistake.

If your policy doesn’t cover misfuelling, you may be able to buy it as an optional extra. Otherwise, you might want to shop around for a policy that offers this type of cover.

Key points

  • Misfuelling is a common error, but don’t assume your car insurance or breakdown policy covers you
  • Check your policy documents to find out if you’re covered for the cost of draining and cleaning, or for accidental damage caused by driving with the wrong fuel
  • If your policy doesn’t cover you, you can buy a specialist, stand-alone policy

What damage can misfuelling do to your car?

Your car is designed to use a specific type of fuel, so putting the wrong one in it can cause major issues. The problems start as soon as you turn on the engine:

Putting petrol in a diesel car

This is the most serious type of misfuelling. Unfortunately, because the smaller petrol nozzles fit easily into diesel cars, it’s much easier to put the wrong fuel into this type of car.

Petrol is more corrosive than diesel and as it moves through your car it dissolves the diesel lubricant which keeps parts moving smoothly.

This increases the friction between parts, which in turn can cause severe damage. In more serious cases, you could even find yourself having to replace the car’s entire fuel system.

Putting diesel in a petrol car

Because nozzles on a diesel pump are usually bigger, they won’t often fit in modern petrol cars. However, if you do manage to use the wrong fuel, the damage is usually much less serious than if you’d put petrol into a diesel car.

Diesel doesn’t ignite as easily as petrol, so you may find the engine won’t start or it cuts out. It can also cause an unusual amount of white smoke to come from your exhaust.

What about E10 fuel?

This new type of ‘greener’ petrol is becoming more common at petrol stations, but it isn’t compatible with a small number of older cars.

In these cases, the car may still run but the E10 fuel can start to damage some of its parts over time. You can check whether your car can take E10 petrol on

If you accidentally use E10, there’s usually no need to drain the tank - instead, just fill the car up with the right type of fuel as soon as possible to dilute it in your car’s system.

However, if you’re unable to start your car after using E10, call a recovery service.

What to consider when choosing a misfuelling cover policy

When you’re looking into whether to buy misfuelling cover you should factor in:

  • Cost - Shop around and compare the cost of policies to get the best deal
  • What’s covered - Some policies may only cover the draining and cleaning of your tank, or just the repairs needed, while others might cover both
  • Cover limits - You’ll only be covered up to a certain amount, so check this meets your needs
  • Terms and conditions - Read the small print to understand what is and isn’t covered
  • Excess - You may have to pay an accidental damage excess if you claim for misfuelling

Can my breakdown cover help if I use the wrong fuel?

Yes, unlike car insurance - which doesn’t usually include misfuelling cover - most breakdown policies will cover the cost of draining your car’s fuel tank and taking it to a garage if needed.

You might have breakdown cover as part of your car insurance or as standalone cover, so check to see whether you’re already covered.

Common misconceptions about misfuelling cover

Although misfuelling cover can help if you accidentally use the wrong fuel, you may be surprised to find out that some policies won’t cover you for:

  • Draining your tank - Your policy may not cover the cost of your tank being drained and cleaned if you use the wrong fuel
  • The cost of repairs - Some policies will cover the cost of repairs but not the cost of draining your tank, whereas others will cover both
  • Starting your car and driving off - Attempting to drive with the wrong fuel in your car can cause real damage and your policy may not cover you
  • Knowingly driving with the wrong fuel - If you realise you’ve used the wrong fuel and still drive the car, you’re unlikely to be covered
  • Damage to the engine - You may not be covered if the engine has been damaged after you’ve used the wrong fuel

How can misfuelling happen?

Unfortunately, putting the wrong fuel in your car is easily done and can be caused by several reasons, including:

  • Being distracted at the pump
  • Driving a new or different car
  • Using an unfamiliar garage that uses a different fuel colour code
  • Rushing when you’re refuelling
  • Driving a diesel car that’s easier to fit a petrol nozzle in

What to do if you’ve used the wrong type of fuel

  1. Don’t start the engine

    Take the keys out of the ignition to make sure this can’t happen

  2. Let the petrol station know

    The staff can help you manage the situation and put safety cones out if needed

  3. Push the car to a safe spot

    Put the car in neutral and push it to a safe place

  4. Contact your breakdown service

    You’ll need a specialist to drain and flush your fuel system

  5. Call your insurer

    If you’re covered for misfuelling they may have a procedure you need to follow to repair your car

Ways to prevent misfuelling

Putting the wrong fuel in your car can be a major hassle, so here are our top tips to help you avoid it:

  • Put a sticker on your car’s petrol cap telling you which fuel to use
  • Stay alert and concentrate when you’re at the pump
  • Don’t rely on the colour of the petrol hose or nozzle
  • Always check you’ve got the right fuel before you press the trigger
  • If you’ve got more than one car, take a moment to notice which one you’re filling
  • Consider buying a device to stop narrower petrol nozzles fitting in your diesel car

Making a claim for misfuelling

If you need to make a claim, you should contact your insurance provider as soon as possible.

Before you call, check you’re covered for misfuelling and have your policy number ready.

Gather any breakdown or repair receipts you have as a result of the misfuelling - you may need to use these as proof.

Will a claim for misfuelling affect my car insurance premium?

Just like any claim you make on your car insurance, a claim for misfuelling is likely to push up your premiums when it comes to renewal.

You’ll need to balance how much the recovery and repairs will cost you, after any excess is applied, to decide whether it’s worth claiming.

You're not the first person to put the wrong fuel in your car and you won't be the last. Don't panic - take a deep breath and check your policy documents to see if you're covered. And whatever you do, don't switch your car on"
Ryan Fulthorpe, motoring expert at GoCompare

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[1]Last checked 3 January 2023