Function

Operating your car with rapeseed oil is normally not covered by the manufacturer. At the moment (2007) Daimler Chrysler released the usage of rapeseed oil for trucks. Provided you have the installation done at an authorised workshop (approx. 8000 Euro) and take into account the changed servicing intervals with corresponding guarantee. In this case, it concerns even a system that can exclusively be operated with rapeseed oil; Often, the starting and rinsing is still done with diesel oil.
With regard to CO₂ emissions it has the same advantages as the bio diesel, also re- cultivatable. The retrofitting costs around 3000 Euro for passenger cars. It concerns changes in the injection system (pressure and other nozzles) and particularly changes of the heater. These changes are more difficult for systems featuring common rail and pump nozzle. Of course, the operation of coldly pressed rapeseed oil is definitely possible for certain applications like larger diesel engines, e.g., in the agricultural area and for long distance traffic. Nevertheless, there are still problems with durability, storage and filtering.

How it works

The provision with vegetable oil is difficult also. While you might be able to refuel a passenger car if necessary with litre bottles from the supermarket for approx. 50 cents/l (2004), this is quite impossible for trucks. So you would have to order bigger units for approx. 43 cents / l with domestic storage or for filling stations at storage companies. There are already very few public filling stations. However, calculating the savings you should take into account the range of action.

The adaptation firms promise to have overcome all difficulties during the winter period. You have to distinguish the operation exclusively with rapeseed oil and the starting and rinsing at the end with diesel oil. However, workshops still complain that damages are caused to the injection system, mainly due to the different quality standards. The emissions of carbon monoxide and hydrocarbon are said to be lower by around 50%; they are in general already relatively low for diesel engines to begin with. In addition, the sooth particle portion is clearly reduced. Actually, naturally derived vegetable oil without specific after treatment for fuels provides no guarantee for any exhaust gas specifications. During the conversion to bio diesel the product is considerably altered. The trend during the production of fuel is, actually, to have rather more than less after treatment. You may name it synthetic fuel on which then again future engine generations will be based to achieve better consumption values and exhaust gas values.

The economic advantages are based on the different taxation of vegetable oil as compared to normal fuel. In Germany 10 cents per litre have to be paid as fuel tax, with a raising trend till 2012 to 45 cents. For modern passenger car diesel engines with direct injection (Do they still produce diesel engines not featuring direct injection?!) the use of vegetable oil or rapeseed oil is a problem. The low efficiency with perhaps lower performance/torque is not even the biggest worry that you should have when using rapeseed oil. Carbonisation of the nozzles and corresponding deposits in the engine are more severe. After a certain period you should also be aware of rapeseed oil entry into the lubricating oil. Please, note that these results have already developed from adding rapeseed oil, let alone operating the engine with pure rapeseed oil.