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[rovardotter rubbertramp]

I have a Mercedes 307D, and one of the biggest reasons that I got a Diesel was the possebilites to convert it to run on vegetable oil.

Does anyone have experience with this? How easy/hard is it to get vegetable oil in Europe?

Thank your for your feedback and advice!

[gc3746]

Hi, I`ve been running vans and cars on used veg oil since 2008, I`ve driven my van, vito 108d to Spain & back 3 times 3,000 mile round trip and have taken all my fuel with me and stored it in the van, saves me £400 in taxes on a round trip.
I`ve driven over 100K on veg and in a nutshell here`s what I have learned

buy your oil in bulk in the UK around 30p per litre from ebay

leave the oil to stand for 2 weeks until it separates good dark stuff at the top light coloured rubbish and water at the bottom, pour the good stuff through a cheap 5 micron sock filter with a metal ring sewn in the top let gravity do the work, this is now clean enough to use as fuel.

You will need to fit a heat exchanger, the only ones that work are the ones that are plumbed into the cooling system.

Your 307 has the inline Bosch injection pump and is indirect injection the best combination for veg oil use.

Due to the age of your vehicle it would be advisable to have your injection pump rebuilt with Viton seals as anything pre early 90`s will suffer from seal swelling and an eventual breakdown due to the oil reacting with the older type rubber seals in the injection pump. google diesel Bob he is a very knowledgeable diesel injection specialist and can do the work for you, he also lists which engines you can run on veg oil and which you can`t ( I am nothing to do with his business, I just came across some good information on his website)

another thing you need to know is what will you do when the weather temperature is below 5c, oil gets thicker. You will place a huge strain on the injection pump, starter motor and battery trying to start the engine, the following solutions all work, but they all have draw backs.

pour 20 litres of hot water over the engine, this will warm the block and allow you to start the engine.

only run with enough veg oil for your journey and a couple of miles before you stop for the night dilute the remaining oil with diesel so it will be easy to start the next morning.

Run a Oil petrol mix, you can add up to 20% petrol to the veg oil this thins it,( I know people who buy mis-fuel in bulk for this purpose 15-30p per litre) but you will need to add a cetane booster, this will knacker the older type rubber seals in the injection pump, not a problem with the Viton seals.

Or the best solution is to twin tank it, I did this to the Vito, basically you fit a small auxillary fuel tank which has diesel in it and you fill the main tank with veg oil, a couple of 3 way valves and some additional fuel hose a and a 2 way switch. When you start the engine it runs on diesel until it is up to operating temperature you then flick the dash switch and it changes over to veg oil, 2 minutes before you reach journeys end flick the switch to purge the system then again just before your turn the engine off back onto diesel ready for the restart the next morning. I did this myself for a cost of £140.

There is something satisfying in repurposing a waste product, which is better for the environment and has saved me around £2,000 a year.