Use of Vegetable oils as a fuel in a Diesel Engine Surf
(Page 2 of 3)

The method favoured by most Surf owners appears to be simply mixing veg-oil with diesel.

Before staring to experiment with this you should first ensure that your Surf is in otherwise good running order, particularly with regard to the fuel system. If you have any leaks or indeed any suspicions regarding the condition of your fuel system, have them properly checked by a competent person before commencing. You should also change your fuel filter and have another on standby, as the veg-oil can have a tendency to lift any dirt or sludge accumulated on the bottom of your tank, this could quickly block even a new filter.

My Surf. I've been using veg-oil mixed with regular diesel in my 3rd Gen Surf for over 4 years (since 2003, a time when veg-oil was dearer than diesel!). I have found thru a process of experimentation using increasingly larger veg-oil blends that my engine seems to accept it without any difficulty. I can easily use 80+% in temps above 14°C and have had no difficulties with 100% at temps of above 22°C.
In winter times I have not yet discovered my max veg-oil limit yet, I've so far used up to 50% at -4°C without experiencing any differences in starting or running, I'll continue to experiment with increased levels this coming winter when it gets cold enough.
I should point out that my Surf has the factory fitted heated fuel filter (part of the Winter pack option package) which no doubt helps me achieve higher ratios than those without it. All temperatures quoted above are according to the Surfs thermometer (however accurate that may be).

Other Surfs. The experience of other Surf owners varies, some have also reported using similar high levels to myself, but a greater number find difficulties with starting require that they use lower ratios. From the reports of other, it would seem most can easily use 50% in the summer and 25% in the winter, many can use even more.

Your Surf. At this point you are kind of on your own, different engines will tend to accept differing levels, this will be due to many factors including ambient temperature and overall wear and condition of the engine and its fuel system. It’s all about experimentation. Try adding about 12 Litres to your tank (assuming a 60L tank, this is 20%) and top up to full with diesel, see how it runs, check it starts well from cold and does not exhibit any lumpiness or uneven running, if all is well then on your next tank try increasing to say 15 Litres and so on.

Ideally you should add the oil to a near empty tank and then fill up with diesel, this way the higher flow rate of the diesel being added from the pump will help ensure they mix more thoroughly, this also ensure you know exactly how much veg-oil you have, as you do not have to add the quantity you have just added to the percentage remaining in the tank in order to calculate your overall ratio.

Don’t forget that if you settle on say 50% during the summer months, you should reduce it during the winter to avoid the risk of gelling. Remember gelling was mentioned above? This is where both diesel and veg-oil will at lower temperatures have altered viscosity. Initially they will reach what is called their cloud point, where they become opaque (you can’t see thru them) at this point the viscosity will rise greatly, reduce the temperature even further and they reach a gel point, as the name suggests, they turn into a jelly like substance which you can forget about using. To prevent this during the winter months, the oil companies add winterising, or anti-gelling agents to their fuel, and for the same reasons you may have to use a higher ratio of diesel fuel in the colder months. Once again the level required is down to experimentation.

A reasonable level of veg-oil use would appear to range from 50-75% in the summer and 20-50% in the winter.

Another point to note, use of any fuel in a moving vehicle requires the payment of various duties in most countries. Using veg-oil without paying such duties would be a similar (if not the same) offence as using rebated diesel such as Red or Green diesel.

In the UK you can use up to 2,500L annually of SVO or WVO without the requirement to pay any duties. You are however required to keep records for 6 years and may need to comply with other regulations too.

I must emphasise again that you use any alternative fuel entirely at your own risk. You should research the topic and satisfy yourself that you understand what you are doing and the possible results before proceeding.

Remember too the many, many advantages of using these more alternatively friendly fuels, be it…

SVO (Straight Vegetable Oil) – Regular Veg oil from your supermarket

PPO (Pure Plant Oil) – Basically the same as SVO, often prepared specifically for vehicle use.

WVO (Waste Vegetable Oil) – Old oil from restaurants etc, filtered, de-acidified, washed etc.

Biodiesel – Fuel manufactured by a chemical process called transesterification



Your choice of fuel can help reduce your countries dependence on imports and the oil producing nations and improve its balance of payments.

Provide more employment in your home country, thru increased use of set aside land and local oil production facilities.

Have a neutral impact on CO2 emissions as the quantity of CO2 emitted when burned is consumed by the replacement plant during its growth cycle.

Substantially reduce the emission of carcinogenic and other noxious particles.



So using veg-oil in place of diesel is not just good for your wallet, its good for your countries economics, and better for the environment. You, your country, and everyone on the planet stands to benefit if sufficient numbers of people make the switch.



Goto Page 3