Soy is usually used as the main stock for BD, because it is cheap to grow, readily grown locally (USA) is typically right in the middle as far as cloud/gel points. Yet yeilds a higher BTU then most oils. For example Rapseed or canola oil yeilds higher BTU's per lb then soy. However it has a higher clouding point, and cost upto 3 times as much to grow, produce and collect oil from the plant itself. Thus per lb is much higher in cost for the little benefit of a few more BTU's.

Honestly, algae is probably going to become the leader in eg oil production in the near future. Algae, grows faster then any other plant in the world, it grows by cellular division. It will continue to produce or grow at a compounding rate until either the food supply has run out or the container is full. 50% of each algae cell is oil. Thus a 1lb container of algae will produce 1/2 lb of oil compared to the soybean which can produce upto 1/3 is weight in oil. Given perfect soil, sunlight,fertilizer and water, oh and temp. algae has been shown to grow in salt water brine, freshwater, little sunlight, high temps,low temps etc. All it needs is water and some sunlight to grow. Therfore it can grow here in AZ, year round, using water run off or salty ground water and not using any farmers crop or public drinking water. a 1000 cubic foot pond can produce 20,000lbs of oil annually now to make math simple lets round a gallon oil up to 10 lbs. That is 2000 gallons of oil(fuel) a year, The average swimming pool in PHX is over 20,000cf. So now basically I could run my own personal truck on the algae grown in a bath tub.

Now I just have to build an algae oil processor. HMMMMMM