Tuesday 8th April 2003


Anonymous PH reader - Reg the Veg - tries it for himself

"Hmm ok, whatever mate" said a long term friend when I mentioned, in a totally unrelated conversation, that you can in fact run diesel engines on peanut oil and vegetable oil. "And I bet the exhaust fumes smell of donuts!" he retorted before doubling up at his own joke. Strangely, my disbelieving friend was correct; more like fish and chips to be exact. It was 1997 and being a mechanically minded person I made a mental note to buy a diesel vehicle and prove him wrong.

Tickell Me

Six years later, after totally forgetting about my intriguing discovery, I was reminded of it during the tanker drivers' strike and proceeded to find as much info as possible about the processes of this bizarre idea. How can a diesel engine run on vegetable oil, from Tescos? After lots of reading, both on the web and books (From the Fryer to The Fuel Tank, by Joshua Tickell is a great source) I bought a kit from Canada, as the ones in the UK are rather expensive (although I would now make my own, which I intend doing).

Bio what? Without going into to much detail there are generally three ways to power a diesel engine with vegetable oil, often called SVO (straight vegetable oil) or WVO (waste vegetable oil) from which Biodiesel is usually made.

WVO to make Biodiesel and is made through a chemical process called transesterification whereby the glycerine is separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerine (a valuable by-product usually sold to be used in soaps and other products). Bio-diesel can be used in any diesel vehicle.

WVO with a suitable additive used simply to reduce the viscosity so it can pass through the injectors and pump without coking. Kerosene is a popular choice, but because of problems with rubber and the unreliable nature of the mix it's not popular.

SVO. New oil used either in a mix with diesel (I used 60% Diesel with 40% SVO), or in a two tank system. (See below)

Veggie Power

My car is a Peugeot 405 TD with a two tank kit from Neoteric in Canada. With a two tank system you start the car on diesel, or bio-diesel, and switch over to veggie via a 6 port valve when the car has warmed up This allows the veggie oil to be heated up, via an electric heater element, to 70c before it gets into the injector pump and therefore reduces its viscosity similar to dino-diesel. Some other kits use the coolant water to heat the veggie oil, but I went down the above route because the electric element gives instant heat and takes up less room.

The only downside is the hassle of buying new veggie oil (with tax paid of course!) and having to keep filling up the small 19L tank.


Generally the car runs the same, with slightly less engine noise and indeed using veggie oil is supposed to give extra lubricity (if that's a real word) that protects the engine. No noticeable drop in MPG or starting in the morning - remember I start on diesel. And of course there is that strange aroma that reminds me of a mobile chippy that wafts pleasantly up your nose when you walk on by.

Nasty Government

Of course you cannot just stick this oil in your car and off you go (unless its Bio-diesel) as there is tax to pay for using it as road fuel. If you do this and don't pay tax it's just as bad as running red diesel (used in agricultural equipment) and liable to the same punishment. You really don't want to mess with the customs and excise people on this one - you have been warned. You will have to register as a fuel producer and although this sounds daunting it just involves filling in a few forms and waiting for the flak! Of course if you buy bio-diesel from a supplier then tax should have already have been paid.

At the moment this concept is quite new in the UK but has been used in Europe and the USA for some time. In fact some European countries have zero rated tax on this type of fuel and they are available in various blends throughout Europe. Rumour has it that the European Union will be implementing a Europe wide "zero" tax on this type of fuel. It would be nice if this were true. I hold my breath.

We however in the UK are subject to various blocks of red tape and until the government sort their policies out the future seems complicated and laden with hazards. At present the tax on Bio-Diesel is set at 26p a litre, and as SVO is 100% ester this should also be the same rate. Dependant on where you live and how clued up the C&E person is will contribute to what rate is applied.

Now what?

I can say now that my car runs on 100% vegetable oil and although it's early days the signs are very encouraging. If it wasn't for the fact that the USA (strangely the worlds biggest consumer of oil) has a number of online resources for people wanting to do this kind of thing I wouldn't know where to start. Because of this I believe that this type of fuel is the future and intend getting in on the act before all hell breaks loose.

Oil supplies are dwindling and we will reach our worldwide midway point within the next 5 or so years. (USA reached theirs in the late 1970's and now import 60% of its oil)

When and if the war on Iraq is successful its "huge" oil reserves (the second biggest next to Saudi Arabia) will only last for 4/6 years at the current world consumption, which by the way will increases with third world countries coming online etc.

Oil will become more expensive as the cost of shipping and extraction increases, so our existing supplies will be stock piled

Vegetable oil is an infinite resource, produces 80% less carbon monoxides and between 20% and 50% of the other pollutants. In fact they are greener than petrol engines.

I've based this article on my own investigations, so I do acknowledge there may be some innacurracies, but I hope it gives you a sense of how the whole issue stacks up.

Running your car on vegetable oil depends on what type of car you have, direct or indirect, whether its ECU controlled or whether it's a Bosch or Luca/CAV pump. The latter do suffer from wear more than Bosch; however it depends on what you are doing to the fuel supply etc. It will take to long to go into to much detail here; needless to say you can do it. Go ahead!

Good luck!