If ya'll are interested, I've been doing some testing and research on the characteristics of soy-biodiesel vs. regular diesel. I'm a senior at Iowa State University and there is a group of us that are testing diesels for our senior design project. We have completed our tests and will be working on compiling all the information into graphs and have been working on writing a technical report about the whole procedure. As there are no significant improvements in Hp, torque and fuel efficiency between premium #2 diesel, 2%, 5% and 15% blends, the B2 (2% soy diesel) has shown the most improvements over the other fuels.