Oops! Wrong fuel!!! - Tom Shaw
After eight years of running a diesel, the other night I done the inevitable and started filling up with unleaded. Fortunately I noticed almost straight away, and only put 2.7 litres in.

A phonecall to the AA brought the assurance that this would not do any harm in a full tank, so I brimmed it, gave the car a good shake to mix it in, crossed my fingers, turned the key and the nice man was proved right. I don't intend to do this again, but out of interest what is the most petrol I could have survived? My tank holds 45 litres.
Re: Oops! Wrong fuel!!! - David Woollard
I look after a 1996 Laguna (non turbo) diesel, took it over from Renault main dealer at 14,000 miles.

At about 25,000 miles owner phoned to say "I need help, the car isn't running properly". The usual enquiries from me and some vauge responses from him including "it doesn't sound right since I came back from town".

Asked him to pop it over that morning for me to have a look. As it arrived chuffing and pinging on the drive (with a very odd smelling exhaust for a diesel) conversation turned to where he'd been in town....for some fuel!!!!!!!

You must have got some dodgy stuff I said, no chance it's been filled with petrol? What followed was a gradual realisation by the chap he had indeed topped it up with petrol. I had to, sort of, guide him along this set of thought processes without making him look a fool.....delicate stuff.

Anyway he had added half a tank of unleaded to quarter of a tank of diesel and driven about 12 miles. I was convinced the engine would be damaged.

Pumped and flushed out the mixture and filled it with diesel, would it start...would it h-ll. Spent quite some time sussing out it had burnt out all the glow plugs. Once these were replaced (what a pig of a job, inlet manifold off) it started fine and has happily run another 20,000 miles.

Happily as far as the engine goes that is, transmission has just suffered total final drive failure. Very poor at 45,000 miles.

David
Re: Oops! Wrong fuel!!! - Alvin Booth
Tom,
The small amount that you put in would not cause any damage to your engine.
The amount that david is describing is a different matter perhaps but probably with more danger to the fuel injection pump than the engine.
Diesel fuel is the lubrication to the finely engineered pump and petrol would not produce the lubricity which it requires.
Back in 1963 we saw the first occasion all over Britain where hundreds of lorries came to a standstill due to the diesel fuel waxing in the filters after a long period of extreme cold. The solution at the time was to put 1 gallon of paraffin to 4 of diesel into the tank. This was a cure to prevent waxing.
We were instructed at the time not to increase the ratio because paraffin was not a good lubricant for the pump.
The following year was I think the first time that the Oil companies began to introduce winter grade diesel onto the market which continues today.
Todays low sulphur diesel fuel is also thought to be of some concern with its lower lubricity. On the continent I have read that some hauliers have had problems with this fuel causing damage to fuel injection pumps. Shell on their web site state that they add an additive to give pump lubrication.
Not wanting to start the supermarket fuel discussion again but do they do the same?

Alvin
Re: Oops! Wrong fuel!!! - Tom Shaw
I stear clear of supermarkets, the fuel is no cheaper and the queue is always longer, particularly in those Tesco filling stations with a mini-market. You never seem to get to the pay desk in less than five minutes while they total up someones weekly shop at the head of the queue.

Mind you, this has been a new slant on the petrol v diesel saga!
Re: Oops! Wrong fuel!!! - Simon

HJ recommends Millers Diesel Powerplus which covers shortcomings of ULSD fuel & other vagaries of fuel production.
Re: ULSD lubrication & additives - steve paterson
Reference the fuel waxing problem of earlier years. In my neck of the woods,
(East Midlands) it was common practice for hauliers to slosh 3 or 4 gallons of petrol into a 30 gallon tank of diesel in freezing weather. I can remember it being cold enough for spilt derv to 'wax' within seconds, but the petrol kept the engines running, with no long term damage.
Re: ULSD lubrication & additives - Stuart Bruce
When ULSD was first used back in Sweden injection pumps were knackered on a very regular basis until they sussed it out and included the lubricants as additives. The first ULSD in this country came from a Swedish company (Greenergy?) and after trials with fleet users found a wider distribution in City Diesel @ Sainsburys. The extra lubricants are added to all ULSD now (allegedly) as the tanker driver goes into the fuel depot, thinks to himself, who am I delivering to next, Shessexaco, therefore they need this set of additives, and in they go in the "correct" proportions,(again allegedly) but it might explain why we see some variation.

There has been a long debate elsewhere (principally concerning smoke reduction) as to whether it is worth adding Millers to ULSD, in the similar vein to the oil additive thread the other week, ie are you mucking up the formula by adding more gunk. Personally I think HJ's got it right, and have never had a problem (or any smoke) since.

Now we have just got to get the Swedes from quadrupling our road tax on diesel motors, I jest not.
Re: ULSD lubrication & additives - Andrew Hamilton
When I first tried City Diesel it appeared, compared with ordinary diesel, to have little smell or colour. It halved the smoke produced. After hj recommendation I always use Millers Diesel Power plus but it does not have any obvious effect on smoke or noise. Round here in Essex/Suffolk the petrol stations match the supermarket price.
Re: ULSD lubrication & additives - Chris
In the manual for my Pug 309 diesel it said: where winter diesel is not available, use up to 25 percent petrol. A couple of litres in a full tank will be just fine.

Chris