In my introduction I mentioned that I was involved with bio fuels, and interest was shown as to the types of fuels and vehicles. I know there are a lot of myths and confusion on the subject of biofuels, and surprisingly, mechanics are the source of much of it for some reason beyond me, altho on the forum I am linked with, there are a good few mechanics who know whats what, and one of the admin is a former diesel specialist, with masses of knowledge on injector pumps. Basically, just about all diesel engines will run fine on proper well made biodiesel. The problems start when you just want to use veg oil, new or recovered. Some cars will run fine with no conversion on just straight veg oil, but they need to be the right engines, and for this, the lucas pump is a definite no no. The delicate structure of the fuel inlet side causes the rotor that drags in the fuel to snap off, and this has happened often with even low percentages and blends, but they are usually OK on proper biodiesel. Bosch pumps will run on either, but for direct injection engines, common rail engines, and PD type systems, a twin tank set up is required to start up on normal diesel. The VW tdi pre PD system is the exception to this due to its differing combustion set up. As the law stands at the moment in the UK, you can use 2500 lts of biofuel per year without duty, be it biodiesel which you make yourself, or new or used veg oil. Records of amounts should be kept for inspection, tho to date I don't think anyone has been asked to produce them. Biodiesel is not easy to make, and needs a proper processor, and various chemicals, but is still made by a good few thousand people. In April this year, the government knocked off the 20p concesion that has been on biodiesel for commercial manufacturers for the last few years, and replaced it with a very complex green credit plan, which many small producers feel they cant comply with, which is resulting in a good few of them thinking of closing, which is a shame, as the price was around 20p cheaper than normal diesel, and so it leaves them having to charge the same, which will lose all customers except those using it for its environmental gains. The enviro gains are many, with Co2 being one of the greatest, as the only Co2 given from it is down to about 20% of diesel fuel, and the plants took this in when growing, leaving biofuels Co2 neutral. There is also no sulphur dioxide, 60% less soot, 50% less carbon monoxide, 10% less nitrous oxide, and up to 90% savings on polycyclic aromatic hydrocarbons[PAHs]. I am not a tree huggin greeny, but for every ton of fossil diesel burnt, there are three tons of Co2 created. There is now 5% biodiesel in all diesel we buy, but countries like France have been putting that in for many years since low sulphur diesel additives were not doing well at compensating for the the loss of lubrication, and biodiesel is many times more lubrication than fossil diesel. Someone mentioned black diesel, but that is a broad term for various fuels, but usually ends up using either old engine oil, which you wouldnt really want in your injection system, or kero etc, but all these are illegal in the UK unless you pay the full road duty of 61p per litre. Sorry for going on a bit.