Diesel particulate filter

A diesel particulate filter (also known as DPF or particulate trap, or referred to as “pollution abatement device”) is a device that reduces the diesel particulate matter or soot from the exhaust gas of a diesel engine. They can be fitted to vehicles in the factory, or once they have been on the road (retrofitted).

 

In summary, they are a filter where exhaust gas pass through, and the particulate matter is traped within the filter. There are two main types of filter:

1. A ‘full’ DPF, which will reduce particulate emissions between 85% and 99%. They are also very effective at reducing emissions of the very smallest particulates which are of greatest concern to health. These are the best air quality option to choose if possible. They do however take some maintenance, and are generally only available for heavy duty vehicles such as lorries and buses.
2. A ‘partial’ filter, which reduces emissions between around 30% and 50%. They tend not to reduce emissions of the smallest particles as effectively as for the larger particles, but need no maintenance eand are available for light duty vehicles such as cars.

If you decide to fit a filter, it is important to get one that is correctly chosen both for your vehicle and vehicle usage, and is certified as meeting the emissions requirements of the LEZ(s) you wish to travel in. In some countries, both types of filter (full and partial) are certified. It is also important when fitting a DPF that you get one that is correctly chosen both for your vehicle and vehicle usage – the company or agency providing or fitting your filter should be able to advise you.

In general, where the LEZ enforces against foriegn vehicles, the authorities will accept the particulate trap certification from the country where the vehicle is registered. If there is no retrofit LEZ certification in your own country, then any existing retrofit certification or national recognition is recommended. In the absence of both of these we would suggest that a particulate filter is chosen that is valid in the country you are travelling to, with a certification from the manufacturer.

In many countries there are also financial incentives to support the retofitting of particulate filters.

Further information on particulate traps can be found from the following external sites:

There is also a training course on particulate filters on the 19th and 20th January 2009 in Munich. More details can be found from the brochure to download.