Contaminated fuel in a Mercedes S420 L? Diesel in your Petrol Mercedes?

We can help!
Call us: 0333 366 0103
Mercedes Fuel Drain


Filling Diesel in a Petrol Mercedes is a regularly occurring mistake. And its remedy is dependent upon several different factors. In the event that you would like to know what it is best to do about it then read on.
Listed below are the key variables to take into account when deciding on whether or not to get a fuel drain:

  1. How much Diesel have you put into the Mercedes, bearing in mind that the fuel tank capacity of your Mercedes S420 L is in most cases about 100 litres?
    1. A small amount of Diesel, less than 5 litres of Diesel in a Petrol S420 L will usually not necessarily be a major problem. Experience has shown us that quantities less than 5 litres (which is close to 5% of the overall fuel tank volume) is in many instances capable of being completely diluted through completely filling up the remainder of the tank with the appropriate fuel.
      It is very uncommon to come across a vehicle going through issues because of lower than 5% wrong fuel contamination. Please remember it is uncommon - in no way impossible to encounter. There are some automobiles that don't stand any amount of contamination in the slightest.
    2. In between 5 and 10 litres of Diesel in the Mercedes (from 5 to 10%) is more of a 50/50 scenario. Our expertise has demonstrated that as many drivers get away with this as all those who don't. Whenever deciding upon whether to risk it and just simply top it up remember that it is the same as betting it all on black - you've got a 50/50 possibility of it being ok.
    3. Anything more than 10 litres of Diesel in your Petrol S420 L must right away be removed seeing as your likelihood of succeeding with this level of contamination is probably lower than one in 50 - genuinely long odds.
  2. Put some Diesel in a Petrol Mercedes and drove it: Have you detected any kind of performance issues after putting the incorrect fuel in the S420 L? If that's the case, have it emptied no matter the amount of Diesel or the contamination percentage. Continually running a motor vehicle that is already beginning to suffer the consequences of fuel contamination can likely cause increasing amounts of harm affecting the fuel system.
  3. Do you want assurance?
    Simply get it emptied. Regardless of the contamination percentage, there is inevitably some amount of risk linked with driving a Petrol vehicle on Petrol contaminated with the incorrect fuel. Probable consequences of driving on the incorrect fuel include things like the engine refusing to start, running unevenly, lack of power, degradation of the high-pressure pump, worn out or clogged injectors, and so forth. These are several of the most typical Diesel in Petrol symptoms, and in the event that you recognise any of them then cease driving and have it drained immediately.

Avoid getting any unqualified mechanic to try to drain your automobile. We are Mercedes specialists and possess the certification and knowledge required to make certain you get back on the road with minimum hassle or trouble.

Put Diesel in a Petrol Mercedes

Accidentally put Diesel in a Petrol Mercedes? Or possibly even put contaminated fuel in your Mercedes S420 L?

Contact us for Help & Recommendations

Give us a call and receive reliable advice and sensible assistance for your exact circumstance

We arrive and do the fuel drain

We can go to you to undertake the complete fuel drain & flush there on scene

Once done You Get Moving Once again

As soon as we are done you are able to get back on your way and get on with your day

Wrong Fuel Drain Specialists

We are the leading wrong fuel drain professionals in the UK, boasting nationwide cover, for Mercedes motorists in particular. We typically deal with:

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

We are Mercedes specialists and have successfully drained hundreds of Petrol Mercedes vehicles. Whether it is at the roadside, on a petrol station forecourt, or even at your home, we are able to get you on the road once again.

The Procedure

The procedure of draining Diesel from a Petrol vehicle is basically the same for most vehicles. Needless to say it can vary to some degree as each brand has their own different fuel system. Even so it still generally follows the following guidelines:

Petrol in Diesel Mercedes

Fuel Drain

Empty the Fuel Tank

View more
Wrong Fuel Drain Mercedes

System Flush

Clean out the fuel lines & pumps

View more
Petrol in Diesel Drain Mercedes

Vehicle Restart

Get the car up and running again

View more


Hours a Day


Days a Week





Our Partners

Just some of the few people we work with to bring you the best petrol in diesel service possible

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.

Contact Us

Should you have any queries or require some help please Call us!
We are able to get you moving once again.

24/7 Mercedes Helpline

0333 366 0103

Our Business Office

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

Weekdays: 9am to 5pm

Important Info

Fully Insured

VAT Registered

APEX Certified


Fully Mobile

Professionally Trained