Today, parallel gasoline-hybrids are often touted as a cleaner, greener alternative despite the simple fact that avoiding purchasing a new car and sticking with your old one saves more energy and environmental impact in almost all cases. Rather than using the new technology to simplify the vehicle, hybrids are more complicated than their predecessors, and the results are not positive. The added weight of the electrical system means that the vehicle is either unusually heavy, or unusually expensive due to the necessity of balancing weight and crash safety. And the hybrid power system, most especially the batteries, comes at a substantial cost premium as well as substantially increasing environmental impact.
We've all seen the poorly drawn "Chick" bible tracts lying everywhere; they're on top of the gas pump at the station, they're on bus stops, they're on tables in fast food restaurants. We see them in the supermarket parking lot, and at the car wash. And one thing they all have in common is that they are thrown on the ground, torn in half, and wind up as a blizzard of litter.
Biodiesel is a diesel fuel made from a non-petrochemical oil, whether animal or vegetable. Vegetable oils are by far the most common stock for biodiesel, with Soy leading the pack at least in the US, in spite of its general unsuitability.
A biofuel is a fuel based on a biological source. This typically means that is derived from plant stocks, but it is also possible to make fuels from animal fat. Biofuels have some major advantages over fossil fuels: