Putting the wrong fuel in your car may seem like a silly mistake, but it happens more often than you think. If you’re in a rush, distracted, or driving a different car, misfuelling is one of those things that can just happen.
You get back in your car, and you’re suddenly struck by the terrible realisation that you’ve just put the wrong fuel in! You might seem embarrassed, but don’t be. Misfuelling happens a lot in the UK, and the good news is that it’s totally fixable, especially if you act fast.
In this blog, we’ll walk you through what to do if you’ve misfuelled your car, how to avoid further damage, and how to prevent it from happening again. Let’s get into it:
Without trying to state the obvious, it’s best that you understand the situation of misfuelling your car:
- Petrol in a diesel car - This is the most common, but it's worth noting that petrol in a diesel car can cause real harm. Diesel engines rely on fuel to lubricate vital components, while petrol strips the lubricate, increasing the risk of damage.
- Diesel in a petrol - This is rarer as the nozzle usually doesn’t fit, but if you’ve found a way, diesel can clog up spark plugs and fuel filters in a petrol vehicle.
If caught early, misfuelling your car is manageable. However, if it makes its way into the engine, it can get costly.
“Most damage from misfuelling doesn’t come from the fuel itself, but from driving the vehicle afterwards.”
So, you’ve put the wrong fuel in your car. The first thing you should do is stay calm and not panic. So what, you’ve made a mistake. Don’t worry, it happens to everyone.
Don’t start the engine
If you’ve realised the mistake at the pump, don’t drive. Don’t even insert the key into the ignition or turn on the engine. This will begin to circulate fuel, which is not what you want if you’ve misfuelled.
Let the petrol station staff know
Head into the shop and let the staff know what you’ve done. They’ll be understanding, misfuelling happens more than you think.
Put the car in neutral and push it over to a safe space
You don’t want to sit there and clog up space at the pump. Put your car in neutral and push it over to a parking space. Rope in a few helpers if you can.
Call a specialist
Get on the phone to a mobile fuel drain specialist (or breakdown company) who will come to you and remove the fuel. They’ll get you back on the road as soon as possible.
If you’ve driven off, pull over safely
If you’ve realised when on the road, pull over, stop the car, and switch off the engine. The less time spent driving, the better. Then do the same as above: get on the phone and ring a specialist.
Call your insurance provider
While waiting for the mobile specialist to arrive, call your insurer and make them aware of the issue.
Please note: Misfuelling is not included in your maintenance contract with Nationwide Vehicle Contracts.
Not everyone will be 100% sure if they’ve put the wrong fuel in their car. You’ll likely have been daydreaming at the pump (or have been in a rush), therefore, it can be tricky to remember. It’s a bit like heading out after dinner and forgetting whether you turned the oven off or not!
The good news is that there are a couple of things you can do to find out if you’ve misfuelled.
Petrol in a diesel car:
- Knocking noise when accelerating
- Engine warning light is on, or the engine completely stops
- Slower acceleration
- Excessive smoke coming from the exhaust
Diesel in a petrol car:
- Engine misfiring
- Excessive smoke coming from the exhaust
- Engine cutting out or failing to restart
If you’ve not started the car, you’re looking at around £150-£300 for a fuel drain.
If you have driven, there’s no real estimated figure. Costs can rise depending on the damage to the fuel pump and injectors, or you might even need a complete system cleanout. The recovery specialist should explain this to you.
You’ll likely not make the same mistake twice, but who knows! If you’re worried about putting the wrong fuel in, there are a few basic steps you can take to ensure it doesn’t happen again:
- Visual reminder - There are stickers you can buy that make your fuel type obvious. These are handy if you regularly switch between a petrol and diesel car.
- Misfuelling prevention device - There are tools you can buy that actually prevent the wrong nozzle from fitting into your car’s fuel filler. They’re affordable and a good option for those worried about misfuelling.
- Get to know your car - This may sound silly, but take a moment to walk around your car, open the fuel cap, and soak it all in. Visualisation is a great way to practice and helps reduce errors.
- Get an electric car - If you’re worried about misfuelling, electric cars are the ultimate solution. It’s not possible to misfuel in an EV as they’re powered by electricity. Simply plug in your EV, and electricity will do the rest!
Thinking about switching to electric? Check out our latest EV lease deals below.
“If misfuelling gives you anxiety, switching to an EV lease is the ultimate solution as you don’t need to go to the pump.”
Misfuelling isn’t really a maintenance issue, but how you look after your car plays a big part in avoiding stressful situations like this.
Think about it, if you let your maintenance standards drop, you might ignore a misfuel-related problem. If your fuel filler cap label is worn, it’s easier to misfuel. Set yourself high standards, and the rest will follow.
This is where leasing a new car really shows its value. Modern lease cars come with:
- Clearer labelling
- Built-in warnings and dashboard lights
- Regular servicing (as part of a maintenance contract)
- Better fuel economy
If you’ve misfuelled in your lease car, don’t panic. Get in touch with your leasing broker or finance provider, and they’ll point you in the right direction.
If you’re a Nationwide customer, give us a call on 0345 811 9595.
Putting the wrong fuel in your car is frustrating, but it’s not the end of the road. What matters most is what you do next. Stay calm, don’t drive, and get help from a professional.
In the long term, the smartest thing you can do is reduce the chances of it happening again. Whether that’s a simple visual reminder, improving your vehicle awareness, or leasing a car that’s fuelling foolproof, do what works best for you.
And if you’re seriously fed up with fuelling, maybe it’s time to go electric.
Ready to avoid costly mistakes and drive smarter? Explore our latest lease deals and find the perfect car for your lifestyle.
Originally posted: 5th May 2025
