first, the kits available aren't that great. This thread at frybrid explains some of the shortcomings of the commercially available kits. It explains how some of the WVO kit retailers are charging you about 50% markup on their off the shelf parts, throwing in some custom parts and packaging it. They have the right to charge you more, and as a customer, you have the right to find better prices for the same quality. http://www.frybrid.com/forum/showthread.php?t=270 This company does have better kits than the others but they are also expensive. Also, WVO is known for clogging and being thick. This is not appropriate for reliability at the levels of biodiesel. It will work and work fine for years if you use high quality fuel, but it's too tempting to skip steps and use lower quality fuel. With biodiesel, if you skip steps, it won't turn out right and you won't (or at least you shouldn't) use it. Reliability overall is still out for debate. It's still not proven 100% one way or another. For that reason, WVO conversions aren't featured on the FAQ pages. Biodiesel, however is 100% proven to be suitable, reliable, and works on diesels up to the pumpe duse technogy. The word is still out on using 100% biodiesel with pumpe duse, small percentages are approved by VW and ar definitely good for the engine.