‘Efficient emissions testing is key for longevity of diesel vehicle parc’ says BM Catalysts

Diesel vehicles remain a major part of the UK car parc, and when it comes to the second-hand market, it goes without saying that regular servicing and maintenance is a must.

As technicians will know, many diesel-powered vehicles feature a diesel particulate filter (DPF) as part of the vehicle’s emission control system. However, if it becomes partially clogged with particulate matter, this will increase back pressure in the engine, affecting fuel economy and reducing power, which over time can cause serious issues.

It is therefore important that diesel vehicles are serviced regularly and correctly to ensure the vehicle is operating efficiently, something which is essential for facilitating proper DPF function. This will help ensure diesel vehicles can continue to be a viable option in the UK car parc, says the commercial director of BM Catalysts, Mark Blinston.

The current UK MOT inspection does not include rigorous emissions testing for diesel vehicles. As it stands, the inspection only includes a smoke meter test, visual checks for smoke of any colour being emitted from the exhaust tailpipe, and for evidence that the DPF is present and has not been removed or tampered with.

However, we’re now seeing legislative changes in countries such as Belgium, Germany, Switzerland, and the Netherlands, in the way that they carry out regular emissions tests on diesel vehicles. The method used allows them to accurately measure the particles that are emitted from the exhaust of diesel cars, commercial vehicles, and trucks. It is designed as a more effective means to detect and remove from circulation diesel vehicles with manipulated, damaged, or removed DPFs.

The UK government is currently consulting the market over introducing this test as part of the annual MOT, with the Westminster Commission for Road Air Quality (WCRAQ) also gathering evidence to shape policy and improve legislation around the quality of air we breathe.

The WCRAQ supports the All-Party Parliamentary Group, which consists of MPs and peers who work together to promote measures to tackle poor air quality.

Barry Sheerman, MP for Huddersfield and one of the individuals who set up the commission, is a keen campaigner around the importance of updating the MOT test for diesel cars, specifically in the testing of DPFs and proposed a Ten-Minute Rule Bill on the topic at the start of 2022.

As is the case in the Netherlands, Sheerman is arguing for the introduction of a DPF efficiency test during an MOT to identify faulty DPFs emitting high levels of dangerous particulates, proposing for an emission limit to be set at 250,000 particles per cm³ in a bid to tackle air quality.

The proposed Bill is evidence that the longevity of internal combustion engines is still being considered, with the debate about clean running of diesel-fuelled vehicles set to intensify. It’s therefore essential that the whole aftermarket plays its part and prepares for any changes in legislation to stay ahead of the curve and ensure emissions are reduced as much as possible.

As a company with strong export links, BM Catalysts is very interested in the legislation already in place in Belgium, Germany, Switzerland, and the Netherlands, and makes continual investments to ensure it goes above and beyond to deliver the highest-quality hot-end emissions control products throughout the European aftermarket.

Despite the 2030 legislation which will ban the sale of new petrol and diesel cars in the UK edging ever closer, vehicles with internal combustion engines will still have a considerable life even after they can no longer be sold as new. Therefore, it’s important that the UK considers introducing more appropriate emissions testing for diesel vehicles, including advanced particle measurements. No official plans to adopt the legislation being rolled out in other countries have been formally introduced – yet.

It is an offence to drive without a DPF if the vehicle requires one. DPFs assist with keeping emissions down, helping ensure we can all continue driving towards improving air quality. As we know, removing the DPF not only causes a vehicle to fail its MOT if it was fitted as standard, but it also means that particles are emitted directly into the atmosphere, which is harmful to the environment and public health.