
Fun with waste cooking oil....
Below is some information regarding the conversion of my car to run on waste cooking oil. This information is specific to the Volkwagen TDI engines.
Whatever kind of vehicle you have with a diesel engine, you'll want to follow these two link before you try the conversion.
http://vegoilconversions.netfirms.com/
http://biodiesel.infopop.cc/eve/forums/a/tpc/f/159605551/m/347104314
I started with a kit from plantdrive.com and a 2000 Golf TDI with 80K miles.
The kit came with everything but the tank.
The critical parts were:
It turns out I could have saved a bit of money by getting the parts separately but I'm not that mechanically inclined and had never seen a working system before. I am very happy with the system and it has paid for itself a few times after approx 16,000 vegoil miles. To this day, I would recommend their kit, though Dana Linscott's plans are definitely the way to go for a serious DIY. Frybrid also seems to have a nice kit, though it's pricey.
The vormax heated filter is awesome but you can't see the vacuum gauge from
the driver's seat. I recommend a vacuum gauge on the dash so you know when
your 10 micron onboard filter is clogged. I filter pretty well and 1 large
filter will last me 7000+ miles. Being in New England, I had to augment the
system with some heat in the tank. Dana Linscott's 'Hotrod' system is excellent.

With the TDI's great fuel mileage you can go pretty far on 12 gallons of oil. If I were to start over, I would use a larger, taller tank since the trunk space is compromised anyway. I keep the hoses to the tank extra long so that I can take the tank out of the trunk to refuel. I pulled up the stock carpet and replaced it with scrap carpet and then a layer of plastic and then some cardboard. You can be as careful as you want but you will spill oil in your trunk eventually.

Here's the switch that simultaneously switches the 6-port Pollack valve to vegoil and delivers power to the vegtherm. I wasn't getting enough heat when it got colder so I added a second 3 port valve and switch that would allow me to loop the fuel or purge any air from the lines into the vegoil tank.

I have to post better pictures of the installation in the engine bay sometime. The Pollack valve is bolted to the battery case. The vegtherm and relay are right in front above the radiator. Do not get one of the older vegtherms! They have the blade-type fittings where the wires connect to it. The heat eventually fries the small-gauge connector wires and they become brittle and break. Plantdrive now sells them with the wires permanently attached to the vegtherm. Besides that, the vegtherm is a great product. It heats up fast and the stock alternator doesn't seem to have a problem with the draw.
I hope this helps...
mzych@hotmail.com