In our state, all No. 2 diesel fuel must contain at least 20 percent biodiesel between April 1 and September 30. 2. From October 1 to March 31, No. 2 diesel must contain at least 5 percent biodiesel.I learned from 2 car dealers that lubricity of biodiesel blends is lower than pure petroleum diesel fuel. A friend of our learned the hard way when the injectors in his Cummins diesel wore out. He now uses Stanadyne Lubricity Forumla in his truck and we use it in our diesel car and SUV too for longevity reasons.