Two Tank System

The general consensus to operate a vehicle on vegetable oil is that it is best to install a second fuel tank, as the oil is very thick and you will find it difficult to start your car on it.  This allows you to purge your fuel lines of Vegetable Oil and start your engine on diesel fuel.

For both of my vehicles, I specifically chose tanks that would not take up space in the cabin.  There are a great variety of tanks available if you have the cabin or boot space.

In my Nissan Patrol, I installed a professionally constructed after market 80 litre auxiliary tank that was originally fitted to a petrol vehicle converted to LPG.  This tank is mounted under the vehicle.  I shopped around and picked one up from a wreckers yard for about $200 including delivery.  The dual filler tube as seen on the front cover had to be made which cost me $350.  I average about 600km out of this tank

In my Toyota Tarago, I have modified an LPG tank which is fitted under the rear of the vehicle.  I picked up the tank and cradle at the wreckers for about $100.  I average about 480km out of this tank.

I have a friend with a Mazda Capella (626) Wagon.  This has a 20 litre plastic jerry can standing in the side spare wheel bay with the fuel line connected into the bung hole at the base.  It would have cost about $25.  He averages about 300 km out of this tank.

One customer uses a series of 20 litre plastic carboys in milk creates.  The create allows him to use an octopus strap to hold the tank in position.  To this he has run a large bore fuel hose through a cap with a one way valve fitted to the end.  To change tanks, he simply undoes the cap, pulls the line out, plunges it into the next container, jiggers it to prime the hose and away he goes.  This allows him to carry as much fuel as he is going to need and quick refuelling without installing a larger tank somewhere.

Another customer has had 100mm deep Stainless Steel tank made to sit flat in the cargo bay of his Hilux Surf, and another who plans to use a 50 litre marine fuel tank in the boot, which you can pick up at a marine shop for around $150.
You might also consider using your existing tank for the vegetable oil, and installing a small auxiliary tank for diesel, as you will be lucky to use 10 litres of diesel a week   A 20 litre marine tank should be plenty, but keep in mind that diesel fuel is more volatile than vegetable oil, should be vented to the outside of your vehicle, and will most likely require certification of some kind.

As vegetable oil fuel is not a mineral fuel, it doesn’t melt plastic or other components.  This allows you to use a variety of materials for storage and collection tanks, or to construct your tank.  With my vehicles I have preferred to install systems that I can still fill with mineral diesel offering a long range diesel solution if I can’t get vegetable oil, as the oil can be blended with diesel fuel.

Your best to check with your local roads authority on the regulations for fuel tanks, even if they contain 100% Waste Vegetable Oil.