Diesel vehicles have come under attack in recent years because of the on-going pollution problems and scandals over emissions testing. Will Calvert writes in The Telegraph about how many British drivers have had their diesel vehicles modified to remove exhaust filters. Is this also happening in other countries?
Diesel drivers face costly repair bill because thousands are driving illegal cars, DVSA finds
Thousands of UK drivers are illegally driving modified cars without diesel exhaust filters, an investigation has found.
Due to processing large amounts of particulate matter from diesel exhaust the filters can easily become clogged and likely to break.
To replace the broken filter can cost up to £1000, so to avoid the cost some drivers have opted to have the filter removed.
The procedure to remove the filter is legal and costs only a few hundred pounds, but driving the modified vehicle is illegal and any vehicle found with a modified filter will be subject to a fine of £1,000 for a car or £2,500 for a van.
Eighteen hundred diesel cars in the UK have been found by The Driver Vehicle Standards Agency to be on the road without the legally required diesel particulate filters.
The pollution produced by the particulate matter in the diesel fumes can be damaging to the heart and lungs as well as unborn children in the womb. Noxious fumes created by diesel engines have been linked by The World Health Organisation to 38,000 premature deaths every year.
The filter works by capturing and trapping soot that is part of the exhaust created by diesel fuel.
The filter cannot remove the soot itself so it has to burn the soot into harmless ash by using heat from the engine of the car.
This process of heating the soot can only happen at very high temperatures such as prolonged motorway driving.
Stop start urban driving which does not allow an engine to heat up for a long period causes a diesel particulate filter to clog up with soot, making it likely to break.
By cutting a small window into the outside of the filter, removing the internal filter and then welding the window shut garages are able to give the visual impression that the filter is intact.
MOTs currently only require a visual test of the outside of the DPF to see if the filter is functional. Current emission tests are also unreliable for detecting the presence of the filter.
The DVSA plans to introduce changes to emission tests that will improve their ability to detect filters that have been tampered with. These tests are not scheduled to be rolled out until May 2018.
DVSA Chief Executive Gareth Llewellyn said: “Vehicles found to have tampered with or missing DPF filters will fail their MOT… DVSA continues to pursue such offences and will take action against any MOT garages found to be conducting illegal modifications.”
Jonathon Grigg, Professor of Paediatric Respiratory and Environmental Medicine at Queen Mary University of London, said the emissions given off by unfiltered diesel engines are “are not taken seriously enough”.
“By removing the DPF you are taking a toxic vehicle and making it even more toxic. When you breathe in diesel emissions a lot of what goes into your lungs is soot.
“Some of that soot will continue to stay in your lungs even after you breathe out multiple times.
“Living in an urban area you only take in a small amount of these particles everyday, but what we are learning is that over the course of a lifetime that these effects accumulate.”
The long term risks associated with exposure to diesel emissions include increased risk of cardiac and respiratory diseases such as asthma as well as slightly higher chance of getting lung cancer.