New Biodiesel Project

Yesterday, while sitting on the black top with my friends, a man named Mr. Ham came to the school and told us about this big project for Ms. Rioux's class.  He said that we would be making biodiesel out of scratch...I thought that he was crazy.  8th graders cant make organic gas.  I was wondering....What is in biodiesel?......What engine does the bus even have?......Does the bus engine have good filters?......How many MPGs does the bus get when it used regular diesel from the gas station?