DfI Proposes New Emissions Test For Diesels

The Department for Infrastructure (DfI) is consulting on an alternative exhaust emissions test for modern diesel cars and light goods vehicles as part of changes to the annual MOT test.

Modern diesel engines can emit high levels of hazardous particulate matter if not properly maintained, and the current diesel smoke test is ineffective in detecting this. The PN test, which is expected to take as long as the existing petrol emissions test, is anticipated to incur no additional test fee. The eight-week public consultation proposes conducting an exhaust emissions Particle Number (PN) test on cars and light goods vehicles (first registered from 1 January 2013) fitted with a modern diesel engine, as a more effective alternative to the smoke opacity (density) test. The relevant legislation will need to be amended to introduce this new diesel emissions test for light vehicles.

DfI is also proposing to amend the legislation to cover vehicles over 3500kg gross vehicle weight. This change would enable roadside enforcement checks on modern light and heavy diesel vehicles to assess the effectiveness of their diesel particulate filters (DPF).

Following the consultation, all responses will be analysed before recommendations are made to the Minister for Infrastructure.