I saw this post and I figured I'd join this forum and share some info as I seem to have a lot of knowledge that I can share on this biodiesel debate and help clear the air.
I've been making biodiesel for well over 7 years. I currently make 2000 ltr batches that all meet or exceed ASTM quality biodiesel specs...mind you it has not always been like that but that another story.
The first truck was a 2004 duramax. I burnt B100 in that truck for as long as I could during the warmer months. usually 6-7 months per year. That duramax ate biodiesel with ease and I NEVER EVER had any problems associated with that fuel that I made, and I must have burnt 20,000ltrs in that vehicle.
I just sold that truck a few months ago and bought my brothers 2008 F250. He had it for 2 years running my fuel. Truck has a 210 Spartan with DPF and EGR deletes. That ford burnt possibly 7000 ltrs now and have not shown any signs of not enjoying homemade fuel.
Will I ever have any issues with biodiesel. I don't know.... I make certain that the fuel meets all tests. And if the fuel doesn't pass than I just put that fuel in my waste oil furnace and I burn it for heat.
I have never done any oil analysis. Now that it's on my mind I think I will just out of curiosity.
Also I had noticed on my GM that I had a small surging at idle once in a while when on regular fuel. It never did it with biodiesel. Possibly cause it's an incredibly oily fuel.