Wrong fuel in your BMW 645Ci? Diesel in a Petrol BMW?

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BMW Fuel Drain


Filling up with Diesel in a Petrol BMW is a regular mistake to make. And exactly what you need to do about it is dependent upon a variety of things. Assuming you would like to know what to do to fix it then please read on.
Listed here are the most important variables to keep in mind when choosing whether to get a fuel drain:

  1. What level of Diesel did you put in the BMW, taking into consideration that the fuel capacity of your BMW 645Ci is probably around 70 litres?
    1. A small quantity of Diesel, as little as 3.5 litres of Diesel in a Petrol 645Ci will more often than not not be a major problem. Experience has shown us that quantities under 3.5 litres (close to 5% of the overall fuel tank capacity) is sometimes able to be completely diluted by thoroughly filling up the rest of the tank with Petrol.
      It's very unusual to come across a motor vehicle suffering from issues because of below 5% incorrect fuel contamination. Remember that it is infrequent - not impossible to find. You can get some vehicles that won't stand any amount of fuel contamination whatsoever.
    2. Somewhere between 3.5 and 7 litres of Diesel in the BMW (from 5 to 10%) is a 50/50 condition. Our practical experience demonstrates that as many drivers get away with this as those people who break down. When trying to decide whether to chance it and just simply top it up bear in mind that it is just like gambling it all on black - you will have a 50/50 possibility of it working.
    3. Anything in excess of 7 litres of Diesel in a Petrol 645Ci really should promptly be drained because your probability of getting away with this quantity of contamination is undoubtedly lower than one in 50 - truly long odds.
  2. Put some Diesel in a Petrol BMW and drove it: Have you detected any kind of performance issues as a result of putting the incorrect fuel in your 645Ci? If that's the case, have it emptied irrespective of the volume of Diesel or even the contamination percentage. Continually running a vehicle that is currently starting to suffer from the effect of fuel contamination can typically end up in more and more damage affecting the fuel system parts.
  3. Are you looking for assurance?
    Then simply just get it drained. Regardless of contamination percentage, there is invariably some extent of threat connected to operating a Petrol motor on fuel contaminated with the incorrect fuel. Probable final outcomes of driving a vehicle on the wrong fuel include the motor not starting, running unevenly, lack of power, degradation of the high-pressure pump, damaged or bunged injectors, and so on. These are some of the most common Diesel in Petrol signs or symptoms, and if you notice any of them stop and get it removed asap.

Refrain from having any unqualified mechanic to attend your car. We are BMW specialists and have got the certification and expertise required to make sure that you are back on the road with minimal hassle or worry.

Put Diesel in a Petrol BMW

By mistake put Diesel in a Petrol BMW? Or even put contaminated fuel in your BMW 645Ci?

Call us for Help & Advice

Call us and obtain sincere guidance and sensible help for your specific circumstance

We come out and drain it

We can come to you to do the complete fuel retrieval & flush right there on scene

Once carried out You Get Moving Again

As soon as we are done you will be able to get back moving and get on with your trip

Wrong Fuel Drain Specialists

We are the leading wrong fuel drain authorities in the UK, boasting countrywide service, for BMW motorists especially. We typically deal with:

  • Unleaded petrol in a Diesel Vehicle
  • Diesel in an Unleaded Petrol Auto
  • AdBlue fuel contamination
  • Water fuel contamination

We are BMW specialists and have successfully drained thousands of Petrol BMW vehicles. Whether it is at the roadside, on a station forecourt, or even at your house, we can get you going once again.

The Procedure

The technique of draining Diesel from a Petrol vehicle is fundamentally identical for the vast majority of vehicles. As you can imagine it does vary to some degree as every manufacturer has their own different fuel system. However it still essentially follows the following principles:

Petrol in Diesel BMW

Fuel Drain

Empty the Fuel Tank

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Wrong Fuel Drain BMW

System Flush

Clean out the fuel lines & pumps

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Petrol in Diesel Drain BMW

Vehicle Restart

Get the car up and running again

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Diesel in Petrol Questions

When someone has put Diesel in a Petrol car they have a few very common questions. So we have compiled a list of the most Frequently Asked Questions for you

I put Diesel in a Petrol car and drove it. What do I do?


Turn off the car as soon as possible and call us. Continuing to run a vehicle on the wrong fuel can potentially damage it. We will be able to give you advice and assistance based on your circumstances

Will driving a Petrol car on Diesel cause damage to it?


It can. However, if the problem is caught and remedied quickly the risks will be minimal. Of the 1,500 vehicles we attend every month, less than 0.5% have suffered and substantial damage requiring parts replacement.

How much Diesel can I get away with in a Petrol car?


The safe answer is none. However you might be able to get away with a very low contamination ratio. That being said, we always highly recommend draining anything over a 5% contamination ratio asap.

I know about petrol in diesel, but what about Super Unleaded?


Putting Super Unleaded, or Shell V-Power, BP Ultimate Unleaded, etc, will have the exact same effect as putting regular unleaded petrol in your diesel car and will need to be drained out and flushed.

Will getting you to do a fuel drain void my warranty?


No! The EU Block Exemption Regulations clearly state that "the work can be carried out by as long as that garage uses manufacturer approved parts and correctly follows the manufacturer's service schedule."

Can I top it up with Petrol and add some 2-stroke oil?


This might work on some vehicles in some cases, but in the majority on instances it won't and you risk damaging the Lambda sensors as well as fuel pump and injectors, just as a regular misfuel.

Get in Touch

Should you have any concerns or want our help please Call us!
We are able to get you moving again.

24/7 BMW Helpline

0333 366 0103

Our Corporate Office

Fuel Fixer Ltd, Linx House, 147 London Road, East Grinstead, RH19 1ET


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