Biodiesel is a fuel that does not contain petroleum. Pure Biodiesel can be used only in diesel engines and I know that biodiesel can be mixed with petroleum for normal petrol too.  Biodiesel is biodegradable and non-toxic, making it a real safe fuel.

For more information about Biodiesel, you can see this website here: Biodiesel

Biodiesel fuel is an alternative fuel that comes from 100% renewable resources.  It burnly cleanly and is often considered the fuel of the future. Biodiesel does not contain petroleum, but can be mixed with petroleum to produce a biodiesel blend that can be used in many different types of vehicles. Biodiesel Fuel is biodegradable and non-toxic, making it safer then common table salt.:)

I think that Biodiesel is an innovative and important fuel that is rapidly becoming more available to the general public.  Right now it can be found around the country.  Although it costs a little more than traditional fuels but rest assured that demand will grow. The public will realize the benefits of a biodegradable fuel source which will ultimately bring down the price.  Right now, though, the cheapest way to get biodiesel fuel is to make it at home yourself.