Run Your Diesel on Cooking Oil

Veggie oil works

Last year I tried this out. Peanut oil is too expensive so I got the cheapest rapeseed or palm oil from the supermarket and poured it straight into the tank of my Volkswagen.

It worked great. I had been warned to mix is 50-50 with regular diesel as it is thicker and especially if the weather is cold then it gets really gloopy. You can cause all sorts of problems for your fuel pump with gloopy oil. It ran smoothly and perhaps a little quieter than with 100% regular diesel. And it has the amazing side effect that the exhaust pipe smells like fresh fries!

Some guys have converted their diesel engines to run on 100% veggie oil. This involves putting a pre-heater in the fuel line to heat the fuel coming into the injectors so that the oil is as liquid as regular diesel. Usually these conversions have two tanks so that you start the cold engine on regular diesel and switch to veggie once the engine has warmed up. With a tank heater to pre-warm the oil I have heard it said that you could run an engine or lard - but I think that is going too far.

But what about tax?

Now to the serious part. In the UK and other parts of the world oils for road use are taxed but there is no road tax on cooking oil. The British tax inspectors have mobile testing units and they do random roadside tests. If you have fuel in a road vehicle which is not taxed they have the power to confiscate your car. You can go through a legal process to declare how much fuel you have used and pay the tax on it but then it comes out as more expensive than regular diesel so it makes it hardly worth bothering.

Real savings

Now the real savings are to be made when you use waste vegetable oil. Anywhere that they cook fries they will change the oil regularly. And probably they will have to pay some guy to come and take the old oil away. It you have the space to strain and filter the oil then you can make your own fuel at virtually no cost. It is very important that you get it clean cause bits of food will clog up your filters something rotten. Look on-line as there are lots of web sites telling you how to prepare used veggie oil for a diesel engine. If you want to do it on a commercial scale there are companies who will sell you the complete industrial scale set up.

Is it green?

When I first looked at this I thought here is something really green. No carbon fossil fuels being burnt. (Veggie oil is carbon neutral.) However it is not quite as simple as it first appears.

Some countries in the tropics are clearing the rain forests to plant palm plantations for palm oil production. The environmental damage being caused is worse than the benefits from using this “green” fuel in cars. So its not a simple issue. But perhaps some of our green future does lie in growing our own fuel oil. Certainly recycling is an environmentally friendly way to use up waste cooking oil. Remember that as well as cars and trucks, trains, boats and heating systems all burn diesel fuel oil.