Been averaging 80% WVO or SVO, canola, soy, corn, peanut. 238,000 miles so far.And NONE of the calamities claimed by a few of the 'knowledgeable' posters to this thread.
I'll try to add some real knowledge.
University study of SVO use in an unconverted DI @ 25% SVO:
Interesting. All the guys I know who run WVO/SVO are doing it in Mitsubishi Delicas Both the L400 and L300. With that engine they can't start it if VO has been left in the cylinder after shutdown, and they need to pre-heat it to about 60c before cylinder injection (at 100% VO). I can run 50% or greater VO in my Delica unmodifed, but only in the summer. In the winter, it gels and stops moving. I have never tried more than 50% in my Delica because of issues others I know have had with it in cold climates.so my system is different from one the OP asked about that is unconverted and running some small percentage ( < 25% ) of VO blended with diesel.
However my system is a single tank, and it starts and runs the first 5 miles on cold VO. From 60 to 90% VO concentration. Over 12 years, that's about 25,000 miles of high concentration COLD VO operation. If anything 'bad' was going to happen, it should have happened by now.
Many TDI's have run blends of 25% to 50% w/o reported problems
I've found that only true problem with running high concentration VO is that when temps are <15*F, it doesn't want to pass through the fuel filter till the engine warms up.