Incorrect fuel in your BMW 850CSi? Diesel in a Petrol BMW?

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BMW Fuel Drain


Filling up with Diesel in a Petrol BMW is a fairly typical problem. And its remedy depends upon a few things. If perhaps you would like to find out what it is advisable to do about it then stay with me.
These are the key factors to keep in mind whenever determining whether or not to have it drained:

  1. What level of Diesel did you put in the BMW, taking into consideration that the fuel tank capacity of the BMW 850CSi is usually about 90 litres?
    1. A modest amount of Diesel, something like 4.5 litres of Diesel in a Petrol 850CSi will in most situations not be a huge problem. Experience has shown us that an amount less than 4.5 litres (close to 5% of the fuel tank capacity) is quite often capable of being sufficiently diluted by means of totally filling up the tank with Petrol.
      It's very unusual to find a motor vehicle having issues because of under 5% incorrect fuel contamination. Keep in mind it's uncommon - definitely not impossible to find. You will discover certain automobiles that won't stand any degree of contamination in the slightest.
    2. Between 4.5 and 9 litres of Diesel in the BMW (from 5 to 10%) is more of a 50/50 situation. Our expertise has confirmed that as many drivers get away with this as all those who break down. When deciding whether to risk it and just fill it up recognise that it is the same as wagering your car on black - you have a 50/50 chance of it working out.
    3. Anything more than 9 litres of Diesel in a Petrol 850CSi ought to as soon as possible be drained out seeing as your probability of succeeding with this quantity of contamination is more than likely less than one in 50 - really long odds.
  2. Put Diesel in a Petrol BMW and drove it: Have you spotted any performance troubles ever since putting the bad fuel in your 850CSi? If so, have it drained no matter the volume of Diesel or the contamination ratio. Continually driving a car that is beginning to suffer from the effects of wrong fuel contamination can only result in more damage affecting your fuel system components.
  3. Would you like peace of mind?
    Then simply just get it removed. Regardless of contamination percentage, there is inevitably a certain level of risk in connection with driving a Petrol engine on Petrol contaminated with the wrong fuel. Probable consequences of driving a vehicle on the wrong fuel include the engine not starting, running lumpy, lack of power, degradation of the high-pressure pump, worn out or blocked injectors, and so forth. These are several of the most frequently seen Diesel in Petrol warning signs, and if you observe any of them then cease driving and get it drained immediately.

Do not simply get any unqualified mechanic to attend your vehicle. We are BMW specialists and have got the skills and knowledge required to make certain that you get back on the road with minimum hassle or trouble.

Put Diesel in a Petrol BMW

By mistake put Diesel in a Petrol BMW? Or even put contaminated fuel in your BMW 850CSi?

Give us a call for Help & Advice

Contact us and obtain genuine guidance and sensible assistance for your specific circumstance

We show up and drain it

We would go to you to carry out the complete contaminated fuel drain & purge there on scene

Once done You Get Going Once again

Once we have completed you can get back on your way and get on with your day

Wrong Fuel Drain Specialists

We are the leading wrong fuel drain authorities in the UK, offering nationwide cover, for BMW motorists especially. We predominantly fix:

  • Unleaded petrol in your Diesel Vehicle
  • Diesel in your Unleaded Petrol Vehicle
  • AdBlue contamination
  • Water fuel contamination

We are BMW specialists and have successfully drained thousands of Petrol BMW vehicles. No matter if it is at the roadside, on a filling station forecourt, or even at home, we can get you on the road again.

The Procedure

The process of getting rid of Diesel from a Petrol car is essentially the same for the vast majority of vehicles. Naturally it does differ to some extent as every make has their own different fuel system. However it still adheres to the following guidelines:

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 FAQs

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.

Contact Us

Should you have any concerns or want some assistance please Contact 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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