Filled up with B100 on Monday. I have been running B50 to B80 for the last few months. The reason I have not been running B100 is the temps get down low 30s to upper 20s. I didnt want to worry about gelling. I do notice a different tone in the motor. It runs really quiet and smooth. It's my view that most do not know about biodiesel and are afraid to use it. There was talk at my daughters school that bio fuels are bad because of what it is. And it's taking away food from us and destroying our land.. I quickly set them straight and gave the short version lecture.