threelander321

Active Member
Hi all need this answering asap please as i have a 170 mile round trip to do tomorrow.I went to top up withfuel today for my journey tomorrow..Now the tank was a little over half full but i had a senior moment and for some reason found myself putting unleaded fuel in the FL2 i think it was on 8 litres before i realised so i stopped then topped it to the limit with diesel.Question is will i be ok for the journey tommorw theres like 72 litres of diesel and 8 litres unleaded in the tank.will it be ok.I,m thinking of topping back up after the first half of the journey.Thanks in advance.
 
I wouldn't worry mate - 8 litres is very little and on that journey you'll soon wash it though. Diesel in a petrol is fatal, but petrol in a diesel is usually OK. Wash it through as quick as you can though, and ideally change the fuel filter once you have.
 
I wouldn't worry mate - 8 litres is very little and on that journey you'll soon wash it though. Diesel in a petrol is fatal, but petrol in a diesel is usually OK. Wash it through as quick as you can though, and ideally change the fuel filter once you have.
Incorrect!!!:mad::mad:
Petrol in a common rail engine can cause horrendous damage to the low and high pressure pumps. These pumps are lubricated by heavy oil (diesel). Putting petrol into heavy oil strips it of it's lubrication ability. This then destroys the oil film, protecting the pumps, causing massive amounts of wear. The ground of metal particles then find there way into the injectors, trashing those too.

If you can't do anything other than drive a petrol contaminated diesel. You MUST add additional lubrication to the fuel. This is best done by adding 100mL of mineral 2 stroke engine oil, per 1Ltr of petrol in the tank. This counters the lack of lubrication, helping reduce the damage.

Putting diesel into a petrol engine isn't so damaging to the fuel system. But it will smoke massively and can damage the O2 sensors and the cats.
 
Virtually everyone I know has pout some petrol in diesel at some stage, usually a minimal mount like this fella has. Long as there's more diesel than petrol run it though and no-one's ever had a problem. Ever.
 
Virtually everyone I know has pout some petrol in diesel at some stage,

Really, I do not think I know anyone who has done it...:p:p:p...............Strange.
Unless it was the old days to stop gelling in freezing conditions.

Cheers
 
Virtually everyone I know has pout some petrol in diesel at some stage, usually a minimal mount like this fella has. Long as there's more diesel than petrol run it though and no-one's ever had a problem. Ever.

I'm presuming the people you know that have done this were using old technology, low pressure diesels.
A modern common rail, high pressure pump has to deliver fuel up to 25,000 Psi. At those pressures, lubrication provided by diesel is essential. Reduced lubrication means increased wear, no question. I've seen it loads of times. Even a 10% petrol to diesel ratio is enough to do serious pump and injector damage.
 
Yup Neilly - really ! Think the only person who hasn't oddly enough is my Mrs....!

Nodge - I've done it in my TDCi Ford....that's modern and it was fine. I ran th flu through in a day I admit, but it was fine My mate did the same in his '12 plated RR Sport and never had an issue. Changed the fuel filter after £10 worth of petrol in it and brimmed with diesel once he realised.

Never had issue.
 
Hi Nodge 68 i have been putting 2 stroke oil in before this happened so i,m guessing there would be still some in the half a tank that was in there before i added the petrol.I lso dropped 50ml of millers in this morning and topped back up after 75 miles.i could put another 100mls of 2 stroke oil in now before i fill up again .Would it be advisable to do so Nodge 68 ???
 
Hi Nodge 68 i have been putting 2 stroke oil in before this happened so i,m guessing there would be still some in the half a tank that was in there before i added the petrol.I lso dropped 50ml of millers in this morning and topped back up after 75 miles.i could put another 100mls of 2 stroke oil in now before i fill up again .Would it be advisable to do so Nodge 68 ???
The 2 stroke oil will do what your FP needs in the way of lubrication ;).

Although apparently petrol in a common rail does no damage.
 
in the old days it was fine to put a gallon (old days) of petrol in a tank of diesel , as it stopped the diesel from freezing , But today there are additives to stop it freezing so there is no need to do it any more and as I have been told never do it in a modern day engine .
 
it was a mistake Teddy i won,t make a habit of it.I think i have been lucky this time i have put a fair bit of 2 stroke oil in the tank since and topped the tank up twice since too so should be well mixed in now.
 
10% of petrol in your tank is going to have a minimum effect on the lubrication of the pump etc. However to be sure, once it gets to half full I would top it up again - preferably with straight diesel.
 
Virtually everyone I know has pout some petrol in diesel at some stage, usually a minimal mount like this fella has. Long as there's more diesel than petrol run it though and no-one's ever had a problem. Ever.
Must know some winners then. But with 40 years driving diesel haven't done it yet, But then on the dash says diesel only along with the filler door diesel only.
 
Must know some winners then. But with 40 years driving diesel haven't done it yet, But then on the dash says diesel only along with the filler door diesel only.

Depends on your mindset I guess.

I did it in our Ford Ranger a few years ago, rushing back to Christchurch the day of the big earthquake while having little luck contacting children etc..

In my case, I put 50 litres of 91 on top of 20 litres of diesel. It was only when I paid for it that I realised. Dumped it all out 200 metres away and refilled with Diesel, no worries except for a light wallet.
 
Depends on your mindset I guess.

I did it in our Ford Ranger a few years ago, rushing back to Christchurch the day of the big earthquake while having little luck contacting children etc..

In my case, I put 50 litres of 91 on top of 20 litres of diesel. It was only when I paid for it that I realised. Dumped it all out 200 metres away and refilled with Diesel, no worries except for a light wallet.
Ouch! You probably realised when the price came up double what you were expecting!
 
It doesn't take much petrol to reduce diesels lubrication ability massively. About 10% is all that's needes. However by adding a 10% 2 stroke to petrol ratio will count the lack of lubrication. This is the safest option, if draining can't be done.

The wife filled her company Astra GTC with about 50/50 mix of petrol/ diesel before driving 10 miles home. The car made it home, except for a MIL and a misfire. I pumped out the mixture of fuels, replacing with fresh diesel and some 2 stroke for good measure. However 3 months later it started losing power, so went into the dealer. There diagnosis was low, high pressure, caused by unusually high pump wear. So it doesn't take long to damage a modern common rail pump.
 
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