With such a short time frame, I took the “Shock and Awe”approach and broke out the nastiest picture I could find: A greased TDI that had severe coking and led to engine failure. I followed that up with test report after test report of failed engines due to Vegetable oil. Severe Engine Damage, carbon buildup, rings sticking, lubrication oil contamination and catastrophic engine failure. I rounded off my opening tirade with pictures of a severely coked and scoured piston and a pile polymerized engine oil that looked like Jello.
Now you may be wondering, as my audience was, why was I being so negative? Don’t I believe in and, in fact, promote the use of WVO as fuel? Yes, but allow me to give you a peek into the mind of an engineer; every thing breaks and at some point, the engine in your vehicle will fail. The use of WVO as fuel in place of Diesel will probably lead to that failure sooner than later. I believe that everyone considering the use of WVO as an alternate fuel needs to clearly understand the risks and evaluate their motivations. WVO is NOTa direct replacement for Diesel; professional WVO conversions are neither cheap nor simple but are designed to reduce if not eliminate the risks associated with WVO. Many people with early Mercedes have found that minimal or no conversion is necessary to run on WVO. In this case, return on investment for the whole vehicle could be made inside of 30,000 miles of driving on WVO. Owners of newer vehicles require a much longer payback and carry a higher risk in the value of the vehicle over the value of the fuel. 
My conclusion is to acknowledge, without prejudice, what you will find in any alternate fuel forum; different people, in different places with different motivations. I am, and this site is, open to cater to the whole spectrum. I believe it is somewhat self regulating as most “shoe string” conversion will be for the inexpensive vehicles and the comprehensive and automated systems will be developed for the more expensive vehicles. As an engineer,I will always be drawn to the failures as that is where improvements can be made.
Leon
