1. Alternative types of fuel

2. ethanol? Biodiesel blends are indicated by the abbreviation Bxx, where "xx" is the percentage of biodiesel in the mixture. B20 fuel is 20 percent biodiesel and 80 percent standard fuel. simple: corn + ferments made from any plant carbohydrates

3. Biodiesel sources contain fat. per gallon Older diesel Mercedes are popular for running on biodiesel. Can be used in most diesel engines

4. Further distance – lower ratio corrosive less fertilizer no drought land depletion

5. Byproducts: ONLY heat & water 60% efficiency evaporates rapidly energy to liquefy asphyxiate warning! easy to ignite