Biodiesel Fuel - The impact it has on your car

With the British recession now in full swing, we'd all like to save a bit of cash, not least when it comes to fuel. But before you go squeezing the oil from free bags of Starbucks coffee grounds, remember to check with your car warranty company if it's really such a good idea....

It has been suggested for some time, more than a century actually, that there are various ways in which to power our vehicles. Only more recently have biofuels been taken seriously but biofuels have proved they are up to the task. Biodiesel is one such future fuel. Ask any farmer worth his rapeseed and he'll tell you the same - what do you suppose a large proportion of tractors are run on? Unfortunately, fossil fuel manufacturers and car manufacturers are yet to come around to this way of thinking. Could it possibly have something to do with the money? More so theirs, rather than ours. So far.
Dr. Diesel demonstrated an engine at the World Exhibition in Paris in 1900 using peanut oil as fuel. More recent developments in technology have made it more accessible to an increased number of people. However much of the development and production of what we now call Biodiesel takes place outside the UK, and information that is UK-centric is slight.
The most common form of biodiesel is vegetable oil. Others have suggested forms of alcohol and even coffee. At the end of the day, despite your wanting of lowering your costs and helping towards a cleaner environment, you must consider whether or not, the use of any biodiesel will in fact invalidate your car warranty.
Before rushing off and assembling or buying your biodiesel processing units, make sure that your car engine is suitable. Not all car engines are suitable for running on biodiesel. The effects of putting biodiesel into a non-suitable engine range from the engine simply not starting to much worse such as the destruction of key parts of your engine. Petrol engines are not suitable for biodiesel or vegetable oil fuel. If you have a petrol engine then you may be able to use bioethanol fuel (some filling stations now offer blends of petrol and bioethanol).
If you have a diesel engine then you should be able to run your car on biodiesel, but it may require a few minor alterations. When running on Straight Vegetable Oil (SVO) or Waste Vegetable Oil (WVO) then more modifications may be necessary. The effects of these fuels and the potential alterations are outlined below.

What are the effects on the engine?

The two main areas of concern are that using biodiesel, can give a diesel engine a stronger solvent characteristic than regular mineral diesel. The other side to this is that its strong solvent property has the benefit of keeping your engine clean and hopefully enabling it to last longer.

The older the car, they tend to use rubber piping in their engines. Any rubber piping in your engine may then perish due to these higher solvent properties of the biodiesel, unlike regular fossil-fuel diesel. Therefore to prevent damage and leaks, replace any such rubber piping with more resistant nylon or plastic piping. Because biodiesel is a stronger solvent means that it removes a lot of the dirt and grime that has been deposited in your fuel tank and the pipes from when the vehicle used mineral diesel. When this is dissolved into the fuel it tends to then clog up the fuel filter with tiny particles, meaning that you will also have to replace your fuel filter shortly after starting to use biodiesel. This will however lessen the more you use biodiesel as it is a cleaner fuel than mineral diesel and so it doesn't deposit as much grime in your fuel tank and pipes. Over time you should recognise the signs if you ever need to do it again. It is advisable to always carry a spare filter. And in winter when temperatures are very low you should consider adding some mineral diesel to your biodiesel to prevent the fuel from becoming too thick to be used by the engine.

What are the effects of SVO and WVO on the engine?

Straight Vegetable Oil (SVO) is obtained from crops such as Rape Seed Oil, Palm Oil and Corn. An engine will normally run better on SVO than on mineral diesel as SVO is a cleaner fuel and has a better lubricating effect on the engine than mineral diesel. The main issue when using SVO is the effect that cold weather has on it. Because SVO is a lot thicker it means that the engine will have trouble starting in cold weather. To avoid this, you can use a Blend or Mixed Fuel that mixes SVO and regular mineral diesel. The colder it is, the higher the proportion of mineral diesel required.


The Chip Fat Conversion

The most drastic option is an SVO Conversion. This is when a special heater is fitted in your fuel tank and that preheats the fuel before the engine is started. When this is achieved, the engine runs a heat exchanger; taking heat from the car radiator and using it to keep the SVO warm when the vehicle is on the move. This uses what otherwise would be wasted heat. The vehicle can also be modified to use a dual fuel system where regular mineral diesel is used to start the engine, then once the fuel is up to temperature the fuel source is switched over to use SVO. Before the engine is switched off the fuel source must be switched back to the mineral diesel so that the fuel lines & injectors contain mineral diesel when the engine is next started in potentially cold weather.

Waste Vegetable Oil (WVO) is normally obtained from restaurants and other food processing outlets. It is basically their used cooking oil - did anyone see the Fifth Gear episode last week with Bill Bailey riding around in a car run on chip fat? Well, it is actually possible, but you do have to know what you are doing! It is very cheap (if you can make friends with enough chippies, and we don't mean carpenters) and is the epitome of a recycled fuel. If your car is able to run on SVO then it is more than likely to be fine on WVO. It is however essential to make sure that your WVO is processed properly to make sure that it has similar properties to SVO.

So what will the impact be on my car warranty?

Yes, running your vehicle on any fuel other than the recommended manufactures stipulated fule will most likely invalidate your warranty! At this present time, most of the major car manufacturers do not officially support the use of biofuels in their cars.
If you decide to use any biodiesel, especially SVO or WVO then it is highly likely that you may invalidate your manufacturers' car warranty. There are only a few cars, mostly those which sell extensively in the German market, which have manufacturers' warranties that cover the use of 100% biodiesel.
So if your car is less than 3 years old, it is likely that you will invalidate the warranty if you use 100% biodiesel. Virtually all new cars are warrantied for fuel containing up to 5% biodiesel but no more. In addition, a number of motor vehicle manufacturers such as Mercedes, MAN & DAF Trucks, recognise the growing interest and have carried out tests to check the suitability of Biodiesel for use in their engines. To be certain that a particular vehicle or engine type is suitable for a B20 blend or B100 Biodiesel, the vehicle manufacturer should be consulted directly.


What if I put bio diesel into an unsuitable vehicle?

Firstly make sure that you do not switch the engine on. Drain the fuel tank & then you would be best calling out a local mechanic to do the rest.

Remember to check the terms and conditions of your new or used car warranty before deciding to save the world by going green on fuel - it could cost you dearly if you don't know what you're doing!