Incorrect fuel in a Mercedes E420 CDI? Petrol in your Diesel Mercedes?

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Mercedes Fuel Drain


Filling up with Petrol in a Diesel Mercedes is a usual mistake to make. And exactly what you should do about it depends upon various things. In the event that you want to know what you ought to do about it then read on.
Here are the most crucial variables to to consider when determining whether to get a fuel drain:

  1. Exactly how much Petrol did you put in to the Mercedes, considering that the fuel tank capacity of your Mercedes E420 CDI is in most cases approximately 80 litres?
    1. A modest quantity of Petrol, less than 4 litres of Petrol in a Diesel E420 CDI will most of the time not really be a major problem. Experience has shown us that an amount less than 4 litres (close to 5% of the total fuel tank volume) is in many instances capable of being completely diluted through thoroughly topping the rest of the tank with the right fuel.
      It is rather uncommon to encounter a motor vehicle experiencing problems due to below 5% wrong fuel contamination. Do not forget that it is uncommon - in no way impossible to encounter. There are actually a number of automobiles that don't endure any degree of fuel contamination whatsoever.
    2. In between 4 and 8 litres of Petrol in the Mercedes (5 to 10%) is more of a 50/50 condition. Our working experience has demonstrated that as many people get away with this as those people who don't. When trying to decide whether or not to chance it and just fill it up recognise that it is the same as wagering it all on black - you have got a 50/50 chance of it being ok.
    3. Anything over 8 litres of Petrol in your Diesel E420 CDI should straightaway be removed because your probability of getting away with that level of contamination is more than likely below one in fifty - definitely big odds.
  2. Put Petrol in a Diesel Mercedes and drove it: Have you spotted any performance concerns since putting the wrong fuel in the E420 CDI? If you have, get it removed irrespective of the amount of Petrol or the contamination ratio. Still driving a vehicle that is already beginning to suffer from the effects of fuel contamination will probably typically result in increasing amounts of damage being done to the fuel system parts.
  3. Are you looking for reassurance?
    You should get it drained. Regardless of the contamination percentage, there is always some amount of threat affiliated with operating a Diesel engine on fuel contaminated with Petrol. Probable final outcomes of driving on the incorrect fuel can include the engine refusing to start, running unevenly, decrease in power, degradation of the high-pressure pump, worn or blocked injectors, and the like. These are a few of the most frequently seen Petrol in Diesel signs or symptoms, and should you recognise any of them stop driving and get it removed right away.

Don't just get any untrained so-and-so to try to repair your vehicle. We are Mercedes experts and have got the certification and knowledge necessary to ensure you are back on the road with a minimum of hassle or trouble.

Put Petrol in a Diesel Mercedes

Unintentionally put Petrol in a Diesel Mercedes? Or perhaps even put contaminated fuel in your Mercedes E420 CDI?

Give us a call for Help & Advice

Give us a call and obtain straightforward guidance and sensible assistance for your specific situation

We show up and do a fuel drain

We are able to come to you to carry out the full fuel retrieval & purge right there on scene

Once done You Get Moving Once again

Once we are done you should be able to get back moving and get on with your trip

Wrong Fuel Drain Specialists

We are the top rated wrong fuel drain authorities in the UK, offering countrywide cover, for Mercedes motorists especially. We principally deal with:

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

We are Mercedes specialists and have successfully drained thousands of Diesel Mercedes vehicles. No matter if it's roadside, on a filling station forecourt, or even at your house, we are able to get you moving again.

The Procedure

The process of removing Petrol from a Diesel car is fundamentally identical for a large number of motor vehicles. As you can imagine it may differ to some extent as every brand has their own different fuel system. However it still essentially follows the below guidelines:

Petrol in Diesel Mercedes

Fuel Drain

Empty the Fuel Tank

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Wrong Fuel Drain Mercedes

System Flush

Clean out the fuel lines & pumps

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Petrol in Diesel Drain Mercedes

Vehicle Restart

Get the car up and running again

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Petrol in Diesel FAQs

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

I put Petrol in a Diesel 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 Diesel car on Petrol 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 Petrol can I get away with in a Diesel 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 Diesel 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

In the event that you have any questions or want assistance please Call us!
We can get you on the road once again.

24 hour Mercedes Helpline

0333 366 0103

Our Business Office

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

Weekdays: 9am to 5pm

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