Petrol in my Diesel

[Dagdusheth]

Hi guys,

Yes, I have done it. I had half a tank of Diesel when I drove into a gas station. Picked up the nozzle and squeezed the trigger. Very quickly I realised that I had picked up the wrong nozzle.

I had pumped in 4 litres of Petrol into the car when I stopped. I then filled it with Premium Diesel all the way. Car started and I drove abfew miles home.

Obvious question: Do I need to drain it? Can I use it by topping up with Premium Diesel regularly? Have I already caused "catastrophic" damage?

My Car: 2012 Mercedes C200 (W204)

 

[Blobcat]

4 ltrs in ~ 60 isn't really an issue, I'd keep it topped up when you get to 3/4 tank and doubt you'll have any issues at all

 

[Botus]

drive slow and keep topping up, I guess 80 ml of oil two stroke oil might help...

if it was mine I would.. and theoretically should be very little difference

maths would be wrong 20 to 25 to 1 ratio

 

[Naraic]

You'll be fine.

 

[EmilysDad]

You'll be fine. It used to be standard practice to put a gallon of petrol into a tank of diesel to help prevent it from freezing in winter.

 

[A.J.]

Hi guys,

Yes, I have done it. I had half a tank of Diesel when I drove into a gas station. Picked up the nozzle and squeezed the trigger. Very quickly I realised that I had picked up the wrong nozzle.

I had pumped in 4 litres of Petrol into the car when I stopped. I then filled it with Premium Diesel all the way. Car started and I drove abfew miles home.

Obvious question: Do I need to drain it? Can I use it by topping up with Premium Diesel regularly? Have I already caused "catastrophic" damage?

My Car: 2012 Mercedes C200 (W204)

You were lucky, as others have said, wouldn't worry about it, just keep it topped up for a little while. I went one better than you, I filled my diesel, when I had one, up with petrol from almost empty. I used the AA to drain it and by the time I had filled up with Petrol, had it drained by the AA and filled it with Diesel it had cost me just over £400 and I didn't even go anywhere

 

[malcolm E53 AMG]

Shouldn’t be a problem as long as the high pressure pump is seeing lubrication with a diesel to petrol ratio of 15/1 as it is in your case it won’t be an issue. I would take BCs advice and top up at 3/4 full. I once did a complete misfill on a sprinter which probably ended up with 15/1 petrol to diesel ratio that made it splutter managed to get back to the petrol station and had the tank emptied and all was well

 

[Dagdusheth]

Thank you everyone.. that does put my mind at ease. Not driving much these days given the lockdown, but will remember to go slow and to keep filling up.

 

[Dagdusheth]

drive slow and keep topping up, I guess 80 ml of oil two stroke oil might help...

if it was mine I would.. and theoretically should be very little difference

maths would be wrong 20 to 25 to 1 ratio

Thank you for that advice! So it should be 20ml of oil per litre of wrong fuel?

 

[Botus]

Thank you for that advice! So it should be 20ml of oil per litre of wrong fuel?

80ml bike two stroke to 4 litre of petrol is 50 to 1 that's probably enough (a little bit just to help)

 

[Rappey69]

I filled my diesel, when I had one, up with petrol from almost empty.

I did the same . what was worse was that i was so far from home, otherwise i would have pumped the petrol into the numerous containers i have and fed it to my boats outboard engine, all 70 odd litres of it but instead had to watch the whole lot get poured into a waste fuel tank and pay £300 for the privilidge and then have to pay to put another 70 litres of diesel in...

 

[A.J.]

I did the same . what was worse was that i was so far from home, otherwise i would have pumped the petrol into the numerous containers i have and fed it to my boats outboard engine, all 70 odd litres of it but instead had to watch the whole lot get poured into a waste fuel tank and pay £300 for the privilidge and then have to pay to put another 70 litres of diesel in...

Welcome to the club I went petrol on the current one, I don't do enough miles to warrant a diesel, plus you can't fill a petrol with diesel quite so easily

 

[Rappey69]

I instantly noticed how easy the fuel nozzle fitted into the filler of the car but the penny did not drop.
The moment i withdrew the filler nozzle the reality of what i had just done dawned on me
Two other cars on the forecourt had just done exactly the same thing !

 

[Kev555]

Wife did that too full tank of petrol in our Mondeo. I was working away at the time and had to pay £80 to get it towed 7 miles to home and then I had to drain it when I got home at weekend and put a filter on at £30. Wife had to pay taxis to work for rest of the week and out the cost of £30 of petrol she put in the car, so a good learning curve for her. Needless to say she never done it since ( famous last words) A gallon of petrol per fill is quite good for cleaning injectors.

 

[LostKiwi]

https://www.misfuellingprevention.co.uk/product/mercedes-benz/

 

[Donald McPherson]

I forgot which is worst? Petrol in a diesel engine or diesel in a petrol engine. Not that I would want either.

 

[LostKiwi]

I forgot which is worst? Petrol in a diesel engine or diesel in a petrol engine. Not that I would want either.

Petrol in a diesel. Petrol detonates in the combustion chamber and removes lubricant from all the high pressure pumps.

Diesel in petrol just smokes badly and fouls spark plugs. Left too long it can wreck catalytic converters.

 

[jp williams]

4 ltrs in ~ 60 isn't really an issue, I'd keep it topped up when you get to 3/4 tank and doubt you'll have any issues at all

That`s what I did with mine 8 years ago and 100,000 miles later--no problem.

 

[John Laidlaw]

Thank you everyone.. that does put my mind at ease. Not driving much these days given the lockdown, but will remember to go slow and to keep filling up.

I’ve done it years ago in a Galaxy (not far far away though!), almost the same as you, kept topping up and there was absolutely no damage for the 4 remaining years I had the car ...

 

[LostKiwi]

I’ve done it years ago in a Galaxy (not far far away though!), almost the same as you, kept topping up and there was absolutely no damage for the 4 remaining years I had the car ...

Did it years ago in my Defender. From empty to full.....
Drove 5 miles before it stuttered to a stop. Called a mate and drained it all out into 4 X 20l Jerry cans. Gave him two for his trouble and kept two for the 101. Refilled with fresh diesel and it ran another 5 years without issue at which time I sold it.
The petrol mix used in the 101 made it a little smoky but again no issues.