bio diesel ?

it depends on the diesel engine, but for older diesels (tractors and trucks), you don't even need to convert the oil to biodiesel. You can add a thinner or thin it with heat.

it takes a lot of land to grow oil crops. figure how much fuel you'd need in a year, and then you can see how many acres you need to grow the oil.

algae has promise, but it is high labor and high initial cost. Also, not many people actually doing it, so you'll have to figure it out as you go.

For a SHTF fuel source I think almost anyone would do better with wood gas

As far as bio, have you tryed makeing it yet ??

I found the titration process a pain in the a*s , as well as the nessary chemicals would have to be stocked in many small sealed containers since iso-alchool asborbs water so well

Theirs also the issue of most bio-fuels becoming soild in cold weather , and the run bio in modern diesel motors it must be made VERY clean / the normal stuff runs great in #2 oil burners thow


2 good articles on bio production / use
http://journeytoforever.org/biodiesel_yield.html
http://www.builditsolar.com/Projects/BioFuel/biofuels.htm

When dino diesel goes above $4 a gallon bio-diesel becomes very cost competitive. Eventually it will replace dino diesel.