Veggie truck?

Hi everyone! I am an inner-city high school science teacher - I got this crazy idea to buy a used diesel truck and show my students how we could convert it to run on waste vegetable oil, attach a solar panel to the roof and have the kids create presentations about alternative energy to give to our school and surrounding schools, churches, etc. Then I received a grant to accomplish this so I had to actually do it ;o) It’s going well - we need to wait till the wvo heats up and thins out before we can toggle from the stock gas tank filled w/regular diesel to the auxillary tank filled w/100 gallons of wvo - here’s my question… do we need to toggle back to the regular diesel for 20 minutes to clear the fuel lines of the wvo before we turn off the truck???

Are you using straight waste oil or has the glycerin been removed? I would refine the waste oil in addition to filtering it for this project. If the oil is filtered and refined, it would work alone (no dual tanks).

If you don’t switch back to diesel fuel, the fuel lines will be full of glycerin which could clog them. Up to 20 minutes is probably excessive; the fuel lines should clean out far quicker than that. But it won’t hurt anything.

Ask Al Gore

I’m guessing by “inner-city” and your user name that you are located in the Chicago area? In that climate, you probably do need to flush some diesel through during the winter, but during the summer, you may not need to mess with the dino diesel at all.

Thank you! for the info - the problem is that we have no space on our campus for a filtering and refining station - this basically has to be a one step process so we have dual filters on both sides of the pump and I’m limited to whatever I can do to the truck to make this work - I’m glad you agree on a quicker flush time on the fuel lines - I’m thinking I can just toggle and wait a few minutes and we’re good.

I would never start any cold engine on cold WVO regardless of temperature (actually I wouldn’t run WVO at all), IMO you need a two tank system if you want to preserve the engine.

These guys have it figured out already… Greasecar at

They provide systems to run diesel engines on straight veggie oil.