Do not try to start the car! If you’ve found yourself here, there’s probably a high chance you’ve put the wrong fuel in your car or van, or one of our hire vehicles. Before continuing reading, we need to make sure you are not about to start driving, or if you have been, you need to stop the car at the earliest and safest opportunity. Putting in even a small amount of the wrong fuel can be highly dangerous and substantially damage the vehicle.
Do not start the vehicle or stop if you already have
If you have accidentally put the wrong fuel in but not started, this is a much easier fix than if the car has already been running. The incorrect fuel will just be sitting in the fuel tank, making it much easier to extract.
Push the vehicle to a safe spot (engine off)
If you have already started driving and just realised, stop as soon as it's safe to do so, as the further the fuel travels through the engine, the more damage it will cause to your car or van. However, if you have not started your car, push it out of the way somewhere safe where you won’t be a hazard to other road users. Put the car into neutral and take the handbrake off so the car will provide less resistance as you push.
Call for help
Hopefully, if you have realised this in time and not left the fuel station then you will be able to call on help from staff or nearby people to give you a hand. If you do not have breakdown cover, they may be able to point you in the direction of a local breakdown service or the nearest telephone if you do not have a signal on mobile. Nationally speaking, you can also call on the AA or RAC. Believe it or not, putting the incorrect in the fuel is very common with over 133,000 Brits mixing the pumps up each year!
So, what’s going on in there?
If petrol has been put into a diesel car
This is the more common of refuelling issues as the diesel pump nozzle is bigger than most petrol filler necks, so it doesn't really fit easily. The issue is with what petrol does to diesel engines. Petrol and diesel engines operate with distinct combustion mechanisms. Petrol engines initiate combustion through spark ignition, whereas diesel engines rely on compression for ignition. This variation significantly impacts the efficiency, power output, and fuel efficiency of the vehicle. Petrol doesn't possess the lubricating properties required for diesel engines, resulting in heightened wear on vital parts. This disrupts the engine's smooth operation, impacting performance and potentially resulting in immediate damage or complete engine failure.
Some symptoms if you are not sure include:
- ‘Knocking’ sounds when accelerating from the engine or slower acceleration
- An engine warning light on your dashboard
- The car cutting out
- You cannot restart or jump your car
- Excessive smoke from the exhaust
If diesel has been put into a petrol car
Less commonly as diesel fuel pump nozzles are wider than petrol fuel openings, diesel fuel entering a petrol engine is comparably less likely to cause damage. However, there are instances where this is not the case. Diesel in a petrol engine will clog up the spark plugs which can cause your engine to cut out, which is extremely dangerous if you have already started driving. Thankfully the fix for this is that the diesel can just be drained in a lot of cases. Some symptoms if you are not sure include:
- Misfiring (the cylinders do not ignite its fuel)
- The engine sounds rough
- Excessive smoke from the exhaust
- The engine cuts out
- You cannot restart or jump your car
If E10 has been put into a diesel or incompatible car
E10 is exclusively for petrol cars and vans, and this ranks not far behind putting petrol into a diesel engine in terms of how often it happens. The nature of the damage behind E10 being put into a non-petrol or non-compatible petrol car lies in what E10 contains. E10 is a type of petrol which can contain 10% ethanol (alcohol in its purest form), replacing E5 which was allowed 5% ethanol. Fuelling an incompatible petrol car may not be as much of an issue, providing you can refuel with E5 as soon as possible. As of 2021 with E10 being introduced to reduce carbon emissions, over 600,000 cars still are not equipped for E10 fuel. You can check if your car or vehicle is compatible with E10 here.
Call your insurance
You may have some time to kill whilst waiting for a breakdown recovery service. Get the call out of the way and notify your insurance provider as this will affect your ability to claim if not reported. Some insurance policies may cover this or offer it as an add on, but providers may vary in terms of coverage. If this is covered, your provider may cover the cost of draining the fuel tank and taking it to a nearby garage. In any case, it is worth seeing if the cost can be covered by your insurance. Similarly, you may wish to check that your car’s warranty is still valid as this may also be impacted by this.
We hope this assists you if you ever misfuelled your car or van, or if you’re just interested! If you’re out on the road on one of our vehicles, give us a call on 01756 792911 immediately and we will do our best to help guide you.
