Thu 22 Jan 2004 16:49 Matts Can you advise? Made a big mistake by putting 2 Litres of Unleaded Petrol in a Pug 405 Diesel. Would this small mix cause serious damage to the car? Many Thanks for your advice. Thu 22 Jan 2004 18:43 SjB P Agree with previous posts. Nothing to worry about in this ratio. As an aside, I was recently amazed to learn that the Lufwaffe mixed petrol with the lubricating oil of their aircraft in cold conditions! Lubrication technology has come on a long way since then, but I found this article interesting: Thu 22 Jan 2004 20:16 Ivor E Tower Up until fairly recently and maybe still ongoing , a bit of petrol was added to the diesel tanks of lorries travelling overland through Europe to Asia to lower the freezing point of the fuel. Thank goodness you realised your mistake so quickly. Thu 22 Jan 2004 21:43 Armitage ShanksP I think that the technique of thinning sump oil with petrol is still used by Alaska bush pilots. It is just to enable the starter to turn the engine at -40C when the oil is like treacle and the engine can hardly even be turned by hand. Presumably when the engine warms up the petrol 'boils off' and everything is back to normal, until the next cold night. Thu 22 Jan 2004 22:33 pastyman A 5% petrol to diesel mix was all that was needed to stop diesel from freezing in a trucks fuel tanks, all though strictly illegal, parrafin did the same job as well. Although diesel doesn't strictly freeze in a trucks tanks, unless you happen to be in Siberia that is. What happens is that wax crystals form in the fuel, thus blocking fuel lines and filters. Every modern truck manufacturer offers as an option, fuel line and fuel tank trace heaters to avoid this problem although the diesel you buy vitually anywhere in western europe is capable of being used without additives down to -15c anyway. Pastyman Fri 23 Jan 2004 19:10 pullgees Some of those folks running diesels on vegetable oil regulary use unleaded petrol as a thining agent to lower the viscosity of the veg oil. Although, I haven't done this myself, a mate has, with no problems for a good few years. I just heat my veg oil. I once put 11 litres of petrol in an old diesel. I got into a flap and had the tank drained, seems I wasted my money. I'm glad this subject came up, I'll know better next time. What harm could it do to a new diesel? Sat 24 Jan 2004 07:11 Jazzmag The mix is between 5-15% unleaded to the oil. It's to aid combustion and starting when cold - and to lower the viscosity. Apparently unleaded actually gives better cold starting than a similar quantity of diesel. Unleaded boosts this closer to the minimum recommended cetane value for diesel fuel, which is 51. The theory goes that, for the same %, the unleaded boosts the cetane value slightly more than the diesel. Incidentally, the owners manual of my friend's car 1980 M-B 300D recommends the addition of up to 20% petrol, in cold weather. So with M-B recommended the use of petrol as an additive and its better qualities as an additive to veg oil, gets you to the dubious mix of 5- 15% unleaded to straight veg oil! Sat 24 Jan 2004 09:38 Sooty Tailpipes I wonder why they used petrol, diesel would have done the same job; diesel mixes lovely with veggy oil and doesn't seperate. Petrol intereferes with the weak Van der Wahl links, but diesel doesen't. My tests showed that white spirit is even better, and can be bought from Makro for £2 for 4 litres, it's also doen't have the safety risk of petrol vapours. Sat 24 Jan 2004 10:21 Jazzmag Hi Sooty. There's been quite a lot of discussion in the newsgroups over the addition of white spirit as a thinning agent. So if you chop and change suppliers of white spirit I guess you? Definitely the case if you? From my own experience, with a PUG 309 GLD, white spirit did indeed give variable results? On a cold day the engine was decidedly unhappy, with lots of white smoke and engine 'hunting' until warm. I also now add around 1% 2-ethyl hexyl nitrate a recognised cetane improver. Definitely better than conventional Optimax dino-diesel, or whatever the 'latest super-fuel' the marketing men have convinced the public they should be buying. Plus far less queuing at a petrol station. Sun 30 Oct 2005 14:07 Supergroove Hi there, I did something very similar to this about 4 weeks ago. Hopefully my experiences will prove useful to someone? I'd owned my 1996 Renault Laguna 2. I wonder if it was because I was at a petrol station other than the one I usually use - I really don't know what happened - anyway, I put in 3. Straight away, I logged onto the internet and did a search - and there were so many conflicting recommendations. Hardly any of these were backed up with any experiences or hard facts. So, since then, I have done about 2500 miles. I used pretty much the full tank of diesel before topping it up each time. I guess there are two schools of thought on whether you should continually top up, or use most of the fuel before topping up. I chose the second as by the time you put your second tank of clean diesel on top of the contaminated, you have diluted it to virtually nothing. The first couple of tanks I nursed the car. There was nothing noticable in the way the car was running, still started and performed like it normally did. Hopefully I haven't done any damage, but then the cars only worth £1000 - I thought it was worth the risk. As an indication, my tank is about 65 litres, so: Tank 1: 3. Danny Blair 1996 Renault RT-D 2.
