It was in the news this week about one of the major airlines using biofuel. For those interested in using it for rolling along, here is a comprehensive manufacturers bulletin I happened to find:
http://www.sequoiaequipment.com/pdf/biodiesel.pdf

Don't know if I'd want to be on a 767, flying over the Atlantic, when a french fry gets stuck in a turbine nozzle...



Ha! Just messing with you....

I have a 93 vintage cummins 5.9. What would I need to do in order to make it run biodiesel?

Jeez, I would've thought getting off the Saudi's oil teat would spark more interest that ridicule. I'm cool with that; there's enough oil in Alberta to put a car in every Chinese driveway.
As far as age goes, my 1987 Buick Grand National run high elevens on pump gas and alcohol injection. It's fun spankin' new Vettes and other $60,000 cars with my lil 6 banger pushing 25 lbs of boost. I'll never own anything newer than OBD 1. I can't see the point. Just cause it's new, doesn't mean it's better.
If I had anything diesel, I'd darn sure be going bio-diesel.

@Richard Muise
Your vintage cummins can be made to run biodiesel pretty easily. The main issues are the composition of the the fuel lines and other 'rubber' components in the fuel system.
Biodiesel, which is vegetable oil with the glycerine removed, has a solvent effect and viton hose seems to stand up better than other type of hose.
Also your tank may have some biology that can get loosened using biofuel so it is a good idea to use a sight glass type filter between the tank and the injection pump to be sure this doesn't get into the injection system.

All told, I have had nine benzes running on biofuels and have gained quite a bit of understanding over the last six years or so.

Something to bear in mind is biodiesel is not the same as vegetable oil or waste vegetable oil.

Biodiesel is available at the pump, sometimes more than, sometimes less than diesel.

On other hand, waste vegetable oil and running your cummins on that will involve some effort on your part.

I'm sure Rusty knows much more but what I have found is that you don't just run down to the local restaurant, pump the oil out of their tank and into yours. Well, you could for a while, then your engine would have problems and all that you saved on fuel would be up in smoke.

The used oil has to be titrated to determine it's ph. If the oil tests too high, like Rusty said, you can't get that out. This oil would be okay to make biodiesel but not for the straight waste oil process.

If the oil falls into the safe ph level, then it can be filtered, dried and most easily diluted with regular no.2 diesel and used to extend your mileage.

A more agressive approach would be to add on board heating and filtering and run a two tank system, diesel for starting, shutting down and purging and a second vegetable oil system for over the road.

From what I have learned, the pre 95 Cummins engines adapt very well and I have a few friends with dodge pickups with this engine who log hundreds of thousands of miles using straight vegetable oil in dilution.

I live in the mild no. california climate, and colder climates would necessitate introducing more heat into the equation because vegetable oil viscosity even in dilution, is heavier than diesel.

So to summarize, it is not difficult, but to do it right involves taking the steps to assure the source of the oil you will using will be the right ph, lightly 'pre-used', and that parts like hoses in your current fuel system are updated to the viton or equivalent hoses that resist solvent action of both vegetable oil and also low sulphur diesel fuel.

Which is something that any diesel motorist needs to address. Diesel fuel has changed and older engines are not receiving the same lubrication from fuel the former diesel formulations provided.

A vintage diesel really needs lubricity in the fuel or some form of additive to make up for what has been lost. Again, these are just comments based on my researches and certainly not authoritative.

Do your due diligence and perhaps you can find a spot you and your cummins are comfortable with in terms of biofuels.