Wikipedia: TDI engines

If you have been in contact with me in the last 4 months, you've probably heard me talk about my new (used) car that runs on biodiesel: its a 1998 Volkswagen Jetta, with the TDI engine. Here is a picture of an identical car.

Mine gets 41 miles to the gallon and it goes FAST. It turns out the TDI is one of the best engines ever made.

Check out previous year results from the International Engine of the Year Awards. In 1999, when VW released the same TDI engine as in 1998, Volkswagen's TDIs won 3 prizes while BMW's TDIs won another 3 prizes.


Today, I checked out the wikipedia entry for TDI engines. The "fuel" section was, in my opinion, pretty clearly oil industry disinformation against biodiesel. Pasted below is how it used to read. So, what did I do? I fixed it. The current fuel section, hopefully still, is my version, loosely based on the previous one:

TDI engines, particularly newer ones with higher injection pressures, are less forgiving about poor-quality fuel than their 1980s ancestors. No. 2 diesel fuel is recommended since it has a higher cetane number than No. 1 fuel and has lower viscosity (better ability to flow) than heavier fuel oils. While some enthusiasts have run their cars on straight vegetable oil (SVO) or waste vegetable oil (WVO), both are discouraged for new engines, especially since the viscosity is much worse than regular diesel. Biodiesel can also be used if it conforms to specifications, though Volkswagen does not endorse its use in high percentages. In fact, there is some concern that using more than 5% biodiesel in the newer engines may void the Volkswagen manufacturer's warranty, especially in the USA. While it is not clear that the mere act of using biodiesel would be detrimental to the warranty, Volkswagen of America does state that "[s]hould the use of substandard fuels, or higher level blends of biodiesel, damage your engine or fuel system, such damage cannot be covered under warranty." Thus a high-percentage biodiesel user who encounters fuel system problems can reasonably expect difficulty obtaining service under warranty if the biodiesel use is apparent to the dealer. Note that defective fuel (e.g. fuel with a high water content), whether traditional or biodiesel, can damage TDI engines; such damage is naturally not covered under the manufacturer's warranty (but the fuel supplier may bear financial responsibility for the damage).

What is that bit about "Note that defective fuel (e.g. fuel with a high water content), whether traditional or biodiesel, can damage TDI engines"???? It would seem that defective fuel would damage any kind of engine, why would anyone consider that useful information?