Petrol in a diesel car?

Petrol in a diesel car needn't be a serious problem. Simply give us a call and we'll sort it all out for you and have you back on the road in no time.

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Petrol in a diesel car: Our Service

Petrol in Diesel

Whether it’s a case of you put petrol in a diesel car or diesel in a petrol car, fuel contamination as it stands today is a very common occurrence and is often encountered by thousands of car owners every year. We are a national 24/7 fuel drain emergency call-out service, able to get you back on the road after a misfuel.

We come out to you and fix the car right there and then - no need for expensive recovery costs or nebulous dealership man-hour fees.


Petrol in a diesel car: Causes


Let’s be honest, at some point we’ve all heard our friends or anybody complain about petrol in a diesel car. This is a very common mishap because the petrol filling nozzle is way smaller than the diesel one and it fits easily into a diesel filler neck. In case you are currently battling with this unpleasant situation or you are just curious about gaining first-hand knowledge about what to do as a preventive measure for any unplanned future occurrence, the guides below will undoubtedly be of great help to you.


Petrol in diesel car Symptoms

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The petrol in diesel engine symptoms include, but aren’t limited to:

  • Engine losing power or dropping into limp mode
  • Excessive smoke or exhaust fumes
  • Engine coughing resulting in the car juddering or spluttering
  • Inability to restart the engine once it has cooled down

A mixture of petrol and diesel makes it impossible to control the ignition and what this leads to is knocking which can end up damaging the car in the long run. The wisest thing you can do is to ensure you stop driving the car and make a distress call to fuel drain specialists that work 24/7 across the UK for immediate repair.

Failure to take the car for repair will mean that the petrol will fill the fuel system of your car making it more difficult to get the contaminated fuel out. And yes, this might come along with some extra fees not budgeted for prior to the occurrence. You don’t really have to give in to the temptation of driving on a few meters ahead – just call for immediate assistance and get your car fixed right there at the roadside.


How to avoid the putting the Wrong Fuel in Car mistake in the first place

Petrol in a Diesel Car Help

Prevention, they say, is better than cure. Even though there are solutions that can be used to resolve the mini crisis of putting petrol in a diesel car, it is way better not to have it occur in the first place. Below are tips that will come in handy to help you avoid a case of misfueling your car.

  • Avoid filling your car in a hurry: This is often the most common reason why people make the mistake of putting petrol in diesel. As much as possible, avoid filling your car in a hurry because this will make you more susceptible to making the mistake. Hence, ensure you are not pumping petrol simply because you are in a hurry - you might regret it later. Petrol and diesel pumps are generally well labeled.
  • Avoid incessant change of filling station: Situations may warrant that you fill your car at different places sometimes. However, as much as possible, endeavor to fill your car at a petrol station that is well-known and trusted by you. The familiarity will bode well for your consistency too. Most of the times, people fill their car with the incorrect fuel because of the all-too-new events that are associated with an entirely different gas station.
  • Avoid distractions while refueling your car: Do not get distracted by talking to people while filling your car as this will make you unable to concentrate on the work at hand. You may later end up finding out that you have already put petrol in your diesel car and you can only hope by then that it isn’t too late already.
  • Pay attention to the filling nozzle: This should be taken more seriously by diesel car owners because statistics have revealed that reported cases of fuel contamination across the UK almost always include those involving filling a diesel car with petrol. The main reason behind this is that the petrol filling nozzle is much smaller than the diesel nozzle. As a result of this, the petrol nozzle is able to fit into a diesel filler neck very easily than it is to fit a diesel nozzle into a petrol filler neck.
  • Pay attention when you switch car: Funny as this may seem, for many car owners having more than one car, this is another probable reason for cases of misfueling. Many often forget to take notice of this change and end up filled up with petrol instead of diesel.

Why is it a Problem

Petrol is a highly flammable and corrosive liquid. Diesel is a heavy oil which is used for lubrication and combustion only at very high pressures and/or temperatures. Just stating this should make it clear why mixing them will not work correctly in an engine.

Having this fuel mixture running through a modern engine can cause a number of issues. Here’s a break-down of possible scenarios:

  1. Generally the first thing you notice when running on contaminated fuel is that the engine just doesn’t run well. It will splutter, chug and possibly die. Additionally it will also be quite smoky and have difficulty in starting.
  2. Petrol will act as a solvent when missed with diesel and will thereby reduce the lubricity of the diesel. This can cause the diesel fuel components to start to wear and grind. The outcome of this – as a worse case – is that small metal filings get ground off and travel along the fuel system and start to clog and break the delicate high-pressure fuel injectors.
  3. A petrol-diesel mix will also have a different octane rating. This will cause it to ignite at a different time than the base fuels. This can lead to engine knocking and, in the worst case, possible piston and cam-shaft breaking and buckling.
  4. Due to petrol’s solvent nature it will slowly eat away at the rubber and plastic fuel lines, tanks and seals in a diesel fuel system.
  5. As diesel will not fully burn in a petrol combustion engine it often ends up in the oil sump. This build-up of diesel in the oil will over-fill the oil and reduce its effectiveness over time. We’ve heard of petrol engine completely ceasing due to this.

So, if you are suffering from this issue give us a call. We can help sort the problem out.

Petrol in a diesel car

Petrol in a Diesel Car Helpline

What to do if you put petrol in a diesel car

If you have put petrol in a diesel car and drove it:

  • Stop driving: More often than not you are faced with the thought of driving even after you aware of fuel contamination in your car. If you have put petrol in a diesel car by mistake and drove it the best bet is for you to stop driving immediately. This should be your first line of action whenever cases of fuel contamination are discovered. Don’t even consider moving your car any further distance.
    Of course, you need to ensure that it is safe before doing so and also put in place danger warning signs to alert incoming drivers of a motor breakdown ahead. Specialists are able to drain the petrol out and repair your car.
  • Drain before you drive: Don’t risk it at all. Starting the engine circulates the fuel along the fuel lines and common rail system. Just ensure the car is completely drained of petrol first and then filled with the right fuel before you kick start the engine again. This is mostly done by fuel specialists (also know as a fuel doctor) and you shouldn’t do this except you have the required skills. Starting the car with the mixed fuel in it would only make the petrol sink further into the bottom of your fuel tank thereby causing damage to the fuel pump and the engine in the long run. Never drive a car that has been mistakenly filled with petrol instead of diesel (or vice-versa) without properly draining it to get rid of the petrol. Once you have been reassured by a fuel recovery specialist that your car is completely drained of the contaminated fuel mixture, you are ready to hit the road once again with full functionality restored.
  • Full diagnosis: This is also to be carried out by a professional and is often carried out after the wrong fuel has been completely drained from the car. The engine management system is diagnosed fully in order to check for any other damage that might have been done to the car. This ensures that your car has been fully repaired and is okay for full use again on the road.
Petrol in a diesel engine

The bottom line


Putting unleaded petrol into your diesel car, or even putting diesel into a petrol, is not a mistake anyone would be willing to make because of the numerous dangers it poses to the car. However, the good thing about this is that it is completely avoidable if you put the necessary precautions in place. What’s more, even if you’re unable to prevent this from happening, there are myriads of solution available in order to get your car repaired and back to work again. Keep in mind the simple steps highlighted above and put them to good use when the need arises. No one is excluded from making such mistakes but what matters most after all is said and done is how to make use of the available solutions in the appropriate manner.


Petrol in a Diesel car Helpline
0800 711 7114

Put petrol in a diesel car

About Us:

We are a 24/7 national wrong fuel drain service and cover the entirety of England, Northern Ireland, Scotland and Wales. We have technicians based in strategic locations around the country to ensure that we are able to get out to most locations within the shortest time possible. Our average call-out time over the last 2 years has been 49 minutes.

We have professionally trained technicians and call-centre staff who are able to give relevant and honest advice and guidance on the subject of misfuelling. We are able to attend all makes and models – including modern vehicles that other service operators tend to shy away from (this includes hybrids).

We are certified to operate on petrol station forecourts, roadside or at commercial or residential locations.

If you have any questions at all about contaminated fuel issues or need us to drain the tank then please don’t hesitate to contact us. We are open 24 hours a day and are always ready and willing to help.

Note: we are not mobile mechanics and will not deal with or address any issues not related to contaminated fuel.