Petrol-y diesel.......
Turbo Mini Forums

Mate of mine has just phoned up saying he has just filled his Pug 107 up with £40-worth of diesel. The car is a petrol model.

He says that it was really low on petrol, warning lights were on, and from a quick google the tank is 35L meaning there can't have been much petrol left in there for him to get £40 of diesel in it.

Luckily he realised what he'd done and hasn't turned the key, so the fuel pump hasn't even primed and pushed diesel through into the filter etc.

My plan is to pump what is in his tank straight into my Audi tank, then fill his car up with fresh unleaded before starting it up. I'll then fill my Audi up to the top with diesel to dilute whatever petrol might be in there.

Anyone got any reasons why we shouldn't do this? I can't see how a few litres of petrol in 30-odd litres of diesel will have much effect on my Audi? Similarly there shouldn't be much problem with the Peugeot if we get as much out as we can?

the peugeot will be fine if you just get as much out as you can.

the audi will be more sensitive. depending on how much petrol there is in the mix it might be alright..it might not!

great help ey!!!

My boss did it with his 530d, i.e. started filling with unleaded then realised after a few litres, stopped then filled the rest up with diesel. Never had any problems.

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Weeellll, (sucks teeth) i know you'd get away with it the other way round.

I'd certain chance it in somthing like an old scort, but on somthing a bit newer i'd be wary, are derv cats diferent to petrol ones?

apart from the cat i'd think it would be ok though, especially if you go easy.

From what I know about fuels, putting any oil in petrol apparently "kills" the octane in it, meaning it is much less potent. Therefore mixing a load of diesel in with it leaving a very low percentage of petrol will surely mean that the volatile nature of the petrol is reduced greatly, thus it is not likely to harm my diesel. Also mine is not a common rail engine, its has an injector pump and mechanical injectors, so if you can run it on bloody veg oil surely a splash of petrol won't hurt it?!

Well thats the theory as I know it anyway. Plus there is £40-worth of free diesel on offer don't forget!!!!!!

We had this problem with a new volvo the prune filled his diesel with petrol, We drained the tank refilled with diesel and added half a litre of engine oil just incase didnt have any problems!

Petrol kills the seals etc in the diesel pump Tom.
Got an idea though, will petrol seperate from the diesel?? Might take abit of time.

Do it. Absolutely no reason why not. Even a 10% mixture in one tank won't hurt anything.

Hi,
The problem is the petrol won't lubricate, the rotary pump needs lubrication as the cam plate is under tremendous stress generating the injection pressures.
Cheers,
Gavin :)

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Tom, your car should be OK but I think the Pug will pink like fook.
Regards
Dave

done this myself in my old 404 diesel, was almost empty but managed to put £15 worth of unleaded in before realising what i was doin, i just brimmed the tank with the normal diesel, and carried on, ran a littls bit sluggish but as soon as i'd run a few galls off kept topping up to dilute as much as possible,

carl

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Don't you even know what car you owned Carl? It was a 405

Cheers for the opinions guys, I'm going to try it, I think with the low percentage of petrol in there it will be OK, there will probably (best estimate) end up being less than 5% petrol by the time I have filled my car up with diesel.

On 29th Jan, 2008 Vegard said:
Don't you even know what car you owned Carl? It was a 405

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Tom if yours is the PD engine (don't know if they go to 6 cylinders)
then Bat is right and Vegard is most definitely wrong as although yours is not a CRD the tolerances are just as tight and much damage will result - a certaqin tuning company i have been known to visit run their 1998 Volvo (PD) on cooking oil and he is storing up an expensive failure for the future

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know

petrols dont mind running on diesel but diesels dont like to run on petrol. (when i say on you know what i mean! i dont mean a whole tank of the stuff!)

you will more than likely get away with it in your audi seeing as the pug didnt have much petrol left in it and you can get more diesel to dilute it.

we get in work quite alot. people fill their diesels with petrol and we drain it out into containers and it goes in a few of the cars. free petrol for a while!!!

i wouldnt be worried about the pug at all IT WILL RUN. yours though, i would put a litre of engine oil in the tank or better yet a diesel additive.

I'm not saying that this should be done every time, but one tank with this mixture once in the engine's life won't destroy this engine in particular. I've consulted a friend of mine on this. However, I don't mind being corrected.

i dont think anybody is wrong here.

you shouldnt run an engine on this sort of mixture as people have been saying as it will eat away at the seals etc etc but one tank of a very diluted mixture with some additive isnt going to cause your engine to blow up as others have been saying.

(please dont quote that if your engine blows up next week )

Do it, keep it topped up just incase and you'll be fine

apparently puting a couple of gallons of leaded into the tank was a trick to get the black hacks through the taxi emissions test. I've known a few people do this in the past but not on something so new as your Audi Tom

how much was the diesel per litre? surely he must have been running on fumes anyway. personnally id use it just make sure you brim your tank then maybe do as nic suggested.

dont think the pump lubrication is an issue as its such a small amount of petrol only once.

but on the other hand is it worth chancing a grands worth of pump for 40 quid of diesel lol lol

another idea use half of what you drained and brim your tank then use the other half the next time you brim it this would dilute any petrol any further.

then itll defo be ok

no longer a series, but still 1.3 turbo.

It will probably be fine.

A mate threw £20 of petrol into his Shogun once, and drove it til it stopped. Only dawned on him what he had done then !!!!
Drained it, and filled with diesel, and its been running fine since ( over a year ago )

Then another mate put a lot of petrol into a brand new Seat Leon ( showroom car lol )....he drove it for a while...it was running funny, but still running. We drained it, filled with diesel, and I think its ok today.

A small percentage of petrol in most diesels wont do any harm. Just keep it topped up to dilute it as much as possible.

As for the petrol car. Just keep an eye on the oil level in the engine for a bit.
The diesel doesnt seem to burn, and ends up in the sump somehow. We filled a crappy old Escort with what we drained from a wrong fill diesel car once. They had filled their diesel to the neck with petrol.
The petrol car did run fine.....then the oil light started coming on. The oil was that thin from being diluted from the diesel !!

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Diesle/ Petrol Mix. I thought it was the trick to do in the extreme cold temperatures to help prevent waxing of the fuel. Now I know the put anti wax agents in the fuel in winter, but what do they do in places like Siberia? Thats what Clarkson used on the Arctic challenge in his Toyota, and thats a modern engine.

I also did this when I had an Escort van, it was a 1.9 non turbo, I managed to put a third of petrol in then realised and brimmed it with deisle. Ran a little rough for a while, but as Carl A said, just keep topping it up at every opertunity. Maybe use some of that new fangled V Power Diesle, might just help it along.

Edited by Sprocket on 29th Jan, 2008.

I agree with sproket, 25+ years ago when diesel was far thicker than the low sulpher city diesel avaiable now it was common for truckers to throw 5l of petrol in their tanks with the diesel to stop it waxing up in the cold.

Admitidly old truck engines are a different kettle of fish to a modern audi lump, but I cant see it causing a problem...