wrong fuel


2016 will see UK roads crowded by almost 35 million vehicles. One third of those vehicles have diesel engines and, until this year, the number of new diesel vehicles being registered has been increasing by a large proportion year on year. As more motorists swap from petrol to diesel vehicles, this has led to a marked increase in the number of incidents where people fill up their vehicles with the wrong fuel type, putting petrol in diesel cars and vans. This, in turn, has led to an increase in the number of mobile wrong fuel recovery companies operating in the UK.

It has been estimated by one of the big three national breakdown companies, that someone, somewhere puts the wrong fuel into a vehicle over 400 times a day in the UK. So the team at Wrong Fuel Emergency decided that there would be a great benefit in bringing this situation to the attention of as many motorists as possible. By putting together this comprehensive guide we hope to be able to dispel many of the myths surrounding what is the best course of action to take when you’re affected by this situation.

Our engineers have many years of experience in this sector. The fact that they are also time served mechanics helps enormously in enabling them to quickly understand how the fuel system on a particular vehicle works. As you would imagine, the basic functions are the same, but component location and layout can be very different from model to model. This wealth of experience has enabled us to compile answers for most of the questions we hear from motorists who have put in the wrong fuel type on a daily basis, and thus we hope that anyone who reads this guide will be better informed should the worst happen to them.


1) What Are The Most Common Wrong Fuel Scenarios And What Do I Do Next?
2) Why Should I Call Wrong Fuel Emergency?
3) What Is The Potential Cost Of Putting In The Wrong Fuel?
4) Why Does Unleaded Petrol Damage A Diesel Engine?
5) Is It OK To Drive With Just A Little Petrol In A Diesel Vehicle?
6) What Sort Of Repairs May Be Necessary?
7) How Do You Perform A Fuel Drain On A Vehicle?
8) Will My Insurance Or Warranty Cover The Cost Of A Fuel Drain Or Any Repair Work?


1) What Are The Most Common Wrong Fuel Scenarios And What Do I Do Next?

There are a few different sets of circumstances that our engineers encounter on a daily basis when they are called out by a motorist who has put in the wrong fuel. Here, we offer advice on the best course of action to take in each case.

a) You have started to fill up and, after putting in 3 or 4 litres of the wrong fuel type, you have realised your mistake and have stopped.

Many motorists have either heard or have read about the myth that a little of the wrong fuel type in your tank doesn’t matter too much. Whether they’ve added a few litres to an empty tank and have then topped up with the correct fuel, or they’ve added a little of the wrong fuel to a half full tank, some drivers are tempted to try to start the car to see if they can get away with it. The vehicle may or may not start depending upon its age and engine type. If it does start the potential for engine damage is severe.

Our advice is that, first of all, you shouldn’t try to start the car to move it. Just inform the forecourt staff as quickly as you can. In the majority of cases they will be familiar with this type of situation and there may be someone who can help you to move your car to a safe place on the forecourt, if possible, where your vehicle is not causing an obstruction to others. This isn’t always easy, however, as without the engine running your power steering won’t be working. If it is absolutely critical that you move your car then you may be able to get away with turning on the ignition of a vehicle (but not starting the car) to release the steering lock or if it has an automatic gearbox so that you can shift it into neutral to allow it to be moved. The fuel pump will be primed but will only draw in a little fuel from the bottom of the fuel tank which is hopefully the correct fuel type unless your tank was completely empty when you pulled in to fill up. This is rarely the case though as even when your fuel tank empty warning light comes on there is still an emergency reserve in there. The forecourt staff may just ask you to leave your vehicle where it is but they will put up cones or safety warning signs. Call Wrong Fuel UK and we will get to you as soon as possible.

b) You have filled your car to the limit and it’s mostly the wrong fuel type but you’ve only noticed what has happened as you have finished.

As in scenario a, don’t try to start the vehicle. Inform the forecourt staff who will take appropriate action. Then, call Wrong Fuel Emergency.

c) You have filled up with a high percentage of the wrong fuel type and haven’t noticed. You’ve then tried to start the vehicle and it either hasn’t started or has carried you a few yards before stalling.

In this case you will almost certainly need a member of the forecourt staff’s assistance to move your vehicle somewhere safe, even if it’s back to the pump that you just left (as long as someone else hasn’t taken your place already). Call us for help.

d) You have filled up with a large quantity of the wrong fuel type, driven away from the forecourt and have now broken down on the main road.

This is the most perilous of the scenarios we encounter every day. The majority of these situations happen during morning or evening rush hour when the roads are busiest. Most importantly, switch on your hazard warning lights to let other motorists know that you’ve broken down. Make sure that your car is in gear and that the handbrake is on. Check that it is safe to exit your vehicle. If you have a reflective warning triangle in your boot and, again, only if it’s safe to do so, erect the triangle behind your vehicle. This is most important if you break down in the dark.

Occasionally, some of our customers are lucky and a fellow motorist will stop to help them push the car to a place of reasonable safety but this isn’t always the case especially when it’s very busy and may be dangerous to exit your vehicle. If you are posing a problem for other road users then call us and let us know about your situation so that we can prioritise your assistance. It might also be a good idea to contact a local police station if possible so that they can take emergency action if necessary while you wait for our wrong fuel engineer.

If you are stationary on the hard shoulder of the motorway after filling up with the wrong fuel at a motorway service station, then you should exit your vehicle on the side furthest from the inside lane and wait for our engineer. If you are blocking a lane on the carriageway itself, then you must leave your vehicle and inform the police as soon as possible to avoid any incidents.

e) You have filled up with the wrong fuel and have managed to get your car home to your driveway.

Call Wrong Fuel Emergency and we can send one of our engineers out to your home to carry out the necessary remedial action. Just let us know what would be a convenient time of the day for you and we’ll make sure that we’re there at the allotted time.

f) You’ve called another company and they have turned up in a scruffy old van and look as though they intend to try and drain your fuel tank into a plastic container. This doesn’t look safe and you don’t want the company to carry out the fuel drain.

It may seem a little strange to include this as a common scenario but our engineers regularly take calls from distressed motorists who have called out another company claiming to be able to perform a fuel drain on a vehicle and then they have changed their mind about using that company for a good reason. Unfortunately, there are elements at work within the wrong fuel recovery industry who do not have the motorists best interests at heart. Here are a few checks that you can make when speaking to a wrong fuel recovery company before booking your fuel drain with them:

  • Do their engineers hold SPA passports to prove that they have been trained to do the job correctly?
  • Is their company registered with the Environmental Agency to handle and transport hazardous chemicals safely?
  • Will the engineer be using a correctly maintained and calibrated pump to remove fuel from your vehicle into a type approved and CE marked fortified steel container?
  • Can I pay for the fuel drain after it has been performed and if I’m happy with the job?

If any of these questions are answered in the negative, or if there is any uncertainty, then we would highly recommend that you avoid the company at all costs. These cowboys prey on motorists who are in a stressful situation. If you are at all uncomfortable with the conduct of a representative from another company, then you have every right to turn them away. Never pay for this type of service up front. A reputable company will only ask for payment on completion of the job to your full satisfaction. If you are threatened or intimidated in any way, call the Police immediately and inform them.


2) Why Should I Call Wrong Fuel Emergency?

What sets us apart from our competitors? As previously mentioned, the wrong fuel industry is very competitive especially around big UK cities. It’s also an industry that most people don’t tend to have any knowledge of and often do not even know of its existence until they need our service. Our engineers are all fully trained and widely experienced when it comes to removing the wrong fuel from a vehicle. We have a close-knit network of personnel to call upon so that we can offer the very best level of service all over the UK. Each of our engineers carries an SPA passport to demonstrate their level of skill and experience and they are all registered with and licensed by the Environmental Agency to handle and transport hazardous chemicals, namely petrol and diesel. These licenses are essential and under no circumstances should you use a wrong fuel removal company whose engineers do not hold such a license. In this job, the safety of the customer and their vehicle is of paramount importance.

Our extensive network means that we can get to you faster wherever you may be in the UK, so we can minimize your delay and relieve the tension of the situation. We are also well aware that putting in the wrong fuel creates a very stressful situation for the motorist and panic and anxiety are commonplace with affected motorists. Our engineers are trained to deal with anxious customers and they will always be courteous, understanding and respectful.

Finally, we are in the enviable position of being regarded as industry experts by many of our peers and we are often asked by companies working in the same industry to assist and advise on particularly complex jobs.


3) What Is The Potential Cost Of Putting In The Wrong Fuel?

This is very much dependent upon the type of vehicle that you drive and what has happened to the vehicle following introduction of the wrong fuel type to the vehicle fuel system. The majority of our work involves 2 basic types of situation:

i) The motorist has filled up with the wrong fuel and has noticed whilst doing it and they have not attempted to move the car.
ii) The motorist has put in the wrong fuel and hasn’t noticed. They have then either started the car and have broken down on or near the forecourt, or the ignition has been turned and the engine turned over but the car has not started.

In the first scenario, many motorists choose to have their cars towed home by their breakdown company or get a local garage to tow the vehicle away. They then find out about and contact a wrong fuel recovery company and book an appointment. This is the simplest of jobs and, dependent upon the make and model of the car, if the engine has not been started then this type of job can cost as little as £99 plus the cost of any fresh fuel used or fuel additive if required.

In the second scenario, the job tends to take much longer when the engine has been turned over as fuel has been drawn into the vehicle fuel system and needs to be flushed out with fresh fuel of the correct type. The job is further complicated if the vehicle has been driven and has broken down on a busy highway. The engineer may then need to move the vehicle to a safe place to carry out the fuel drain and, as the vehicle has been driven, a fuel system flush as well. These extra activities mean that the engineer has to spend more time on the job and so it will be more expensive; somewhere between £130 and £250 depending upon the type of vehicle.

It is very important that you give as much detail about your situation as possible when you first call our number so that we can give you an accurate indication of cost over the phone. Always check the price beforehand and never use a wrong fuel company who try to charge you upfront before doing any work. You should only pay for the work when it has been completed to an acceptable standard, i.e. the work has been completed carefully and safely and the vehicle engine is running normally.

In comparison, some motorists who are unaware of the wrong fuel emergency industry, and who do not have the means to do an internet search from a phone, will contact a local dealer or mechanic. In these cases, motorists usually pay around £400 to £500 for the tow and fuel drain service. Unfortunately, most general mechanics are not fuel drain experts and the job is often not done thoroughly. Contaminated fuel remains in the vehicle fuel system and related problems occur at a later date meaning more expense and inconvenience for the motorist.

On some very rare occasions, mainly when the affected vehicle is an older model with a high mileage or has an unusual fuel system configuration, you may need to swap the fuel filter, fuel pump or both. If the vehicle engine has had as much as 10 to 25% of the wrong fuel added and then this has then been topped up with the correct fuel type and the vehicle has been driven a long distance (this may or may not work depending upon the vehicle), then the potential damage may turn out to be very costly indeed with the very worst case scenario seeing damage to fuel system, engine and exhaust components. This can all add up to a very costly repair job running to as much as £2000 to £3000 depending upon the vehicle model.


4) Why Does Unleaded Petrol Damage A Diesel Engine?

Unleaded petrol and diesel are very different fuel types and consequently, petrol and diesel engines operate differently as well. Diesel fuel has lubricating qualities which a diesel engine relies upon for efficient operation. The internal components of the fuel system take advantage of this lubrication quality where there is metal to metal contact between them. Petrol does not have any lubricating qualities and if introduced to a diesel fuel system it can severely compromise the operation of its moving parts causing a build-up of friction and dramatically increasing the wear rate of components. As if this wasn’t bad enough, petrol is also a solvent which will damage the internal seals of a diesel engine where they come into contact with the fuel. Over time, this can lead to catastrophic failure of engine parts.


5) Is It OK To Drive With Just A Little Petrol In A Diesel Vehicle?

The simple answer is NO!

This is probably the most commonly observed myth with regards to a wrong fuel situation. Depending upon your vehicle you may be able to put a large quantity of unleaded petrol into a diesel vehicle fuel tank, top it up with diesel and then start and drive it. Just because the engine starts and the vehicle runs, it doesn’t mean that everything is OK. The previous information in section 4 describes why you most certainly should not continue to run a vehicle with contaminated fuel in the tank. The long term damage caused will come back to haunt you at a later date and will mean that you’ll be facing a very expensive repair bill at some point in the not too distant future.


6) What Sort Of Repairs May Be Necessary?

Earlier in this guide, we advised that older vehicles with high mileages may need some repair work following a fuel drain and fuel system flush. It would be prudent to replace the fuel filter and possibly the fuel pump. Ask your engineer for advice regarding your particular vehicle as some makes and models of vehicle are more prone to potential issues than others.

It is difficult to predict what sort of damage may be done to a vehicle as there are so many different makes and models all with different fuel systems and engines. In cases where the vehicle engine has been running for some time with the wrong fuel in the system, there is enormous potential for serious wear damage through friction between internal fuel system and engine components. The wear damage introduces swarf (tiny metal particles)to the fuel in the engine which can block and cause damage to the fuel injectors. When failure of these components eventually occurs it will mean replacement of injectors, engine valve guides and seats and, it is also highly likely that the exhaust catalytic converter will need replacement. These components are expensive to replace both in terms of part price and labour time required to replace them on a diesel vehicle.


7) How Do You Perform A Fuel Drain On A Vehicle?

Pumping contaminated fuel out of a vehicle fuel tank may sound like a fairly straightforward task but due to the complexities of modern vehicles, it is actually anything but straightforward. Our engineers’ experience means that they have knowledge of the differences between the fuel systems of different makes and models of vehicles which is essential to enable them to get the job done properly. The danger of using a company whose engineers are inexperienced, is that some contaminated fuel may remain in the vehicle fuel system potentially causing damage as previously outlined.

Our mobile wrong fuel emergency vehicles are fitted with the very latest equipment in wrong fuel recovery and storage systems. We use a pump unit with a capacity of 250 litres and a variable fuel drawing rate which can draw up to 25 litres per minute, although to avoid damage to the vehicle fuel system we fine tune the draw rate as the job progresses. All possible safety measures are employed whilst the fuel drain is in progress and this is absolutely essential as the contaminated fuel is a highly flammable substance. The pump and storage unit is fitted with a roof vent and an ATEX flame arrester.

Once as much of the contaminated fuel has been removed from the tank as is possible with the pump, the fuel system and tank are flushed through with fresh fuel of the correct type. This is also removed from the system to ensure that no residual contaminated fuel remains. The vehicle is then refuelled with the correct fuel type and the engine is started. The fuel system is checked and monitored for a few minutes to ensure that there are no problems. Once the customer and the engineer are satisfied that the job has been completed, only then will payment be requested.


8) Will My Insurance Or Warranty Cover The Cost Of A Fuel Drain Or Any Repair Work?

We would advise caution here when dealing with your insurance company or a main dealer regarding your vehicle warranty. Some insurance companies offer protection against accidental mis-fuelling but the normal cost of a fuel drain may not even be as much as your insurance excess and a claim could push up your premium next year. As far as vehicle warranties are concerned, it is unlikely that component replacement following putting in the wrong fuel will be covered. Be careful if you’re requesting a fuel pump or fuel filter change from your main dealer. They may ask why you want this done and if they suspect that it’s due to a wrong fuel incident then they may tell you that in order to maintain the vehicle warranty, you have to have components such as the fuel tank and injectors replaced at your own expense. We have heard many a tale whereby this exact situation has occurred and we are asked by the motorist to offer advice on how to handle it.