biodiesel is a great idea and i fully support it... although there is the
whole issue of converting the frier grease into the biodiesel.

You can run pure grease in you diesel automobile if you first *heat up the
grease and inject while warm*.  I have personally installed 3 greasel kits
into an 86 turbo diesel jetta, mid-70 mercedes and a 2001 john deere
tractor with great success.

here is the kit we got:
http://www.greasel.com/
read about it there.

there are a few other kits, but this is what we choose for some reason.

we get grease from a local restraunt and filter it a few times (using a
solar filter setup with a few 5 gallon buckets and a large and small
pore-size filter).  the grease we get for free.  Jetta milage is about 40
mpg. on grease we have better power and no black smoke.

cheers
matthew

Matthew Pollard          "Racing with the wind and flirting with death
Dept. Of Chemistry        So have a cup of coffee and catch your breath"
University of Idaho
www.uidaho.edu/~poll7356