To answer your question fully B means Bio, and the number after it means the amount in percent that is blended with Petroleum based Diesel. B20 has been tested thoroughly by the military and has shown no significant dissadvantages. Yellowstone National park in Wyoming has run B100 for years now in their equipment and had no problems until on very (-37 degree) night. Rudolph Diesel invented the Diesel Engine to run on Peanut oil (not good in cold weather) and we have butchered it so that reverse engineering needs to be done to get back to his roots. I do like the Idea of running on SVO, however I am against WVO because of the water and FFA (Free Fatty Acids) that can damage injectors and pumps, and making Biodiesel out of it instead eliminates, for the most part, those factors. I would be glad to have any discussion with anyone about Biodiesel at any time, and would be willing to travel a short distance from Southern NH to help anyone that needs it. Just PM me.