09/10/2025
HAVE YOU HAD YOUR DPF REMOVED/ DELETED/ MAPPED OUT BEET THE RUSH AND GET THE DPF REPLACED NOW TO AVOID DPFS BEING PUT ON BACK ORDER AND PRICE INCREASING
Particle Number (PN) testing is a proposed MOT change in the UK to measure the quantity of harmful diesel particles, replacing the current smoke density test, and effectively identifying damaged or removed Diesel Particulate Filters (DPFs). The Driver and Vehicle Standards Agency (DVSA) has trialled PN testing in garages to assess its practicality and has found it to be an effective way to detect DPF issues, aligning with stricter emissions controls to improve air quality.
Why PN Testing is Proposed
Harmful Particles: The current MOT test measures smoke density but doesn't measure the size or quantity of the harmful particles within the smoke.
DPF Integrity: PN testing helps determine if a vehicle's emission control system is working correctly, particularly to identify if a DPF is damaged or has been removed.
Air Quality & Health: These smaller particles are known to be harmful when inhaled, and PN testing aims to improve air quality and public health.
What's Happening with PN Testing
Trials: The DVSA has been conducting trials in garages to evaluate different PN testing equipment models and gather data for a potential implementation.
Government Consideration: The government is considering introducing this stricter testing method, and decisions will be based on further research and consultations to balance benefits with costs.
European Precedent: Some European countries, such as the Netherlands, Belgium, and Germany, already include PN testing in their vehicle inspections.
Potential Impacts
For Garages: Implementing PN testing would require MOT centres to invest in new equipment.
For Motorists: More vehicles might fail their MOT due to stricter emissions standards, potentially leading to higher repair costs for owners.
Next Steps
The DVSA will continue to gather data from trials and conduct further consultations to decide on the best way to implement PN testing in the UK MOT.