Vegetable oil !!! Sunflower Oil !!

[venetian-red]

Maybe a slightly tongue in cheek post, but has anyone any experience of running their VW Diesel on sunflower oil / vegetable oil (paying the duty of course); is it worth it and are there any pitfalls. Just curious.

[passat 130 tdi]

you only need pay duty if you use over 2500 litres a year IIRC . I gave up using it when gordon brown started charging as much for it as derv was at the pumps. not in my passat though , i dont think the pd engine likes it.

[zollaf]

i look after 2 pd engined cars that run on veg oil. they are both fitted with kits from a german company called elsbett. they both seem to run ok, but they did cost nearly £2k to convert.

[jas1500_1]

I went to a car garage in bridgend a couple of months back and they had about 15 cars which had all packed in because they were being run on veg oil! I think the guy said it was the injectors that weren't lasting!?!? (don't quote me on that) saying this a boy i know was at 1point calling in tesco's for 5 gallon drums of oil and pouring it straight in! he had a rover220 TD though and i don't think he had any trouble. Let us know how it goes if you do try it.

[venetian-red]

With the price of Sunflower oil as it is and the fact that my car is mapped, don't think, on balance, there is any real benefit of me going down this route. With regards to the previous post, I too knew someone who ran an old (ish) non Turbo'd Rover 414 (I think it was) Diesel on Sunflower oil and it ran perfectly. Thanks for your contribution everyone, I know this has been discussed before, but just wondered if anyone, more recently, had any experience of this.

[garnier]

it's over a pound a litre now ain't it?

Unless you can get used oil for free, what's the point?

[johnna]

It should not be entertained in a DI engine IMHO.

Please let me qualify my angle on it too, I run a 406 xud9te on 100% chip fat (28k and counting) and put 37k on a 306 with the same engine.

Currently, as stated members of the public have an allowance of 2500 litres before they pay the higher duty.
I pay £14 for 20 litres of newly processed oil. Old (used) oil needs to be refined, not just to remove fish tails, but to purge out water.

There is no such thing as a safe pour it in and drive set-up.
The elsbett systems are called 'twin tanks', they start the car on diesel and end the run on diesel, switching over to veg oil only when a certain temp is met. Veg oil emulsifies at a much higher temp than pump diesel. So a clagged up fuel line won't flow!

The way I understand it: molecular structures are more complex in veg oil and take longer to thaw/ to mix with air and to compress to the point of instability that drives a diesel engine. The pre-cumbustion chamber on an IDI engine can accomodate this, whereas direct injection does not.

The injector types are different to. I understand IDI injectors are pintle valves working to tighter tolerances than petrol injectors. DI injectors squirt diesel through 'piezo' (sp?) crystals at huge pressure, these tolerances are tighter still and get gummed by veg oil.

To finish off: in my cars I advance the point of injection timing by 4deg, add pump diesel when the temperature falls in winter to aid viscosity, renew engine oil and filter every 4k, ensure the pump and injectors are bosch (lucas items fail on veg oil, their lubrication journals are too narrow), get the injectors pop tested and make sure the thermostat housing gets hot early.

People have run the older IDI VW engines on veg oil to now problem, but I'd also suggest a fuel line warmer was a good idea on those cars.

HTH,

Johnna.

[vwtdi130pd]

have a look on this
http://www.vegetableoildiesel.co.uk/forum/index.php

[OpenRoad]

I am running a 2004 1.9TDi (130BHP) on a 50/50 mix of pump diesel and reprocessed chip oil.
The engine starts ok and runs fine, even though the air temperature is below 0C.
I have spoken to a VW tech about the use of re-processed fuel. He warned that the PDi engine uses a two stage pressurisation system. The fuel pressure of the first squirt into a cylinder, during the induction stroke is 180Lb psi. At the start of the pressurisation stroke a second squirt of fuel is injected @ 300Lb psi. It is this duel pressure system that gives the PDi engine its potency, it is also this system that make the engine unsuitable for 100% bio-fuel as it could pre-ignite in the injector.
At higher ratio's, I did notice a deterioration in performance so pulled back to 50/50
One plus point was that prior to trialling bio-fuel, the fuel gauge was very erratic. I could drive 400 miles on the first half tank, and only 180 miles on the second half tank. This was 'annoying'.
Post bio, the fuel gauge tells the truth. The more oily liquid must have cleaned up the fuel gauge sender unit.

[johnna]

RE: cleaned up fuel level sender.

The first fuel filter replaced after an svo conversion is usually filthy. The SVO is claimed to 'clean out' the system.