Is biodiesel a clean alternative for anyone with a diesel engine? The fellow in the first clip believes so, but his gloss over the environment's ability to sustain a large acreage of feedstock crops may be naive and self-serving. Just because Canada has a lot of land and clean water, doesn't mean it's a good idea to use it all to grow (genetically modified) soy or canola for the convenience of car-owners. As many commentators have noted, biodiesel's green benefits start to drop off when manufacturers run out of cooking, vegetable and animal oils to recycle.

The second and third clips follow an entrepreneurial chap who makes his own biodiesel. It might be more complicated than you thought....