If you're going to actually be making biodiesel, in a reactor with lye
and that whole deal, then you don't need to make any changes
necessarily, although you'll want to watch the filters and fuel lines
and change 'em when they start looking "bad".

If you're just talking about dumping filtered WVO into your tank, then
there's more to discuss and it comes up frequently enough that a search
of this group with Google Groups will yield interesting info.

To start:

http://groups.google.com/groups/search?q=alt.auto.mercedes+%22vegetable+oil%22&s
tart=0&scoring=d&

Good luck,
-tom!

--

Go for it! Like Tom P. says keep an eye on the fuel filters since the
biodiesel is a great solvent which loosens up everything that has gotten
stuck in both your tank and fuel lines. Did the same with filtered WVO mixed
with kerosene, gasoline and some additives and it works great. Cheap too.