Running Your TDI on Vegetable Oil
I’d heard you could use vegetable oil as a fuel, and after reading James Morfee’s article on using vegetable oil I decided to start investigating this alternative fuel source as there seem to be several benefits.Firstly, of course, it’s cheaper. If you can get old oil for free and use less than 2500l per year, then you are exempt from paying duty.
I’ve also been led to believe that the vegetable oil can clean up your engine as it loosens up all the gunk the diesel leaves about the place. This does mean when you first start using vegetable oil you need to carry a spare fuel filter. Lastly there are environmental benefits; Vegetable oil is a carbon neutral fuel. The plants grown to produce the fuel have already absorbed a level or carbon equivalent to what it will produce when burnt as a fuel. If you use old filtered oil then you’re double recycling as the oil has already served its purpose!
There is plenty more help and advice available in books, websites and forums which I shall list at the end of this article.
After much reading and question asking I decided to buy a twin tank system from Mike at Biotuning. (For more information on the various methods of using vegetable oil refer back to James Morfee’s article) Mike has been running on vegetable oil for some time and has gathered together what he considers the best components for oil conversion and, along with all the accessories required, created an easy to install kit. All you need extra is a second fuel tank of your choice.
Heat exchanger Heated fuel filter Pollak Valve and switch (Electric tank switch) Heater hose and connectors Fuel line and connectors Various other clips connectors and ties.
I began with the switch and cabling as this was relatively quick and easy (and it was raining) I placed the tank selector switch with amongst the window switches and ran the control cables through to the engine bay
The heated fuel filter contains a heated element that runs down the centre of the filter which is fed from the vehicle coolant system. The small problem this causes is that to change the filter you need to be able to lower it the full length of the heater element. To enable this, I built a steel frame to position the filter over the largest gap in the engine bay. Once the frame was installed I fitted the filter, heat exchanger, and pollak valve in the gaps. I then set about connecting up the heater plumbing.
I took a feed from the cabin heater lines which then runs to the heat exchanger and heated fuel filter in parallel, and then back to the cabin heater return. This system will ensure the vegetable oil stays nice and hot and runny.
My second tank for the startup diesel will be going in the boot, so I began arranging fuel lines. The original fuel lines will be used for the vegetable oil, as will the original tank, so I need to reed a feed right back to the boot. This line is all included in the kit. I followed the route of the current fuel lines along the vehicle and cable tied the lines in place.
At this point it became holiday season and although all the fuel lines where in place I had a lot of holiday miles to drive. Being the cautious type I didn’t want have to tell my Grandmother I wouldn’t make it because I’d accidentally broken my engine as I’d rushed the job. So for now I’m still running on normal diesel, but hopefully by the time you read this I’ll be leaving an aromatic chip shop trail round Southampton.
Useful Links:
www.biotuning.co.ukwww.vegetableoildiesel.co.uk
www.smartveg.co.uk
www.dieselveg.com
www.biodiesel.co.uk
www.biodieselfillingstations.co.uk
www.ravenfamily.org/andyg/vegoil.htm
www.vegburner.co.uk
www.greasecar.com (US)
www.frybrid.com (US)