Thank you for adding to my credibility Bill! I have almost 100k miles on straight bio-diesel in the Route Rabbit and I'm just getting rolling on the Mercedes cars. I will most likely do a conversion on the '76 and run it on Straight Waste Veggie oil, rather than using bio-diesel in it. The pump (injection) is a much better candidate for this than is the rotary pump in the Vw's. There seems to be less problems associated with the "inline" type pumps. It has something to do with the rotary type pumps having a "sensor" in the first part ( there are actually 2 pumps in the injector pump on these, I'm referring to the "transfer" part of it ) What this does is sense how viscid the fuel is and adjusts the pressure accordingly. This causes problems when you are "preheating" the used veggie oil to 170°F , which makes it thinner and thus the pressure is adjusted causing a negative effect. (because it is thinner than petro diesel as well as hotter!) The Mercedes pump is not negatively effected by this from the research that I have done. Anywho! Hppy Clattering all! Tom