I second the "holy crap" comment above.
$13,000 buy-in, to make $1 a gallon biodiesel.
Are there annual or periodic maintenance costs on this equipment?
Is the waste oil always free?
How many gallons can it produce before the equipment is scrap (if applicable)?
Were there any other equipment costs to 'complete' the overall package? eg storage tanks, pumps, nozzles, etc etc?
let's say the answer to all the above were zero, so you';re saving what, $3 a gallon?
that 4333 gallons to break even, or 86,666 miles at a pessimistic 20 mpg
assuming you aren't near home every time you need to refuel, say that's half the time, then doubles to 173,333 miles to break even
sounds like a plan only a tree-hugger could love... more power to you.