Reduce Emissions and Pass the MOT with Wynn’s

A helpful guide from Wynn’s

How can emissions affect your MOT?

Protecting the environment is a big concern for governments. They aim to reduce pollution emissions and improve air quality in cities. That is why they have included and reinforced emissions tests during MOT inspections.

Why do MOT tests include an exhaust emission test?

The emission test purpose is to ensure that the vehicle’s engines operate correctly and to keep pollution to a minimum. If vehicles are not serviced regularly, they may not pass the annual MOT test.

What is an emission test / Diesel cars?

During an emission test, the vehicle’s tailpipe gets measured to ensure the vehicle does not exceed current testing limits. 

The diesel emission test measures opacity – the density of particles exiting the exhaust.

This is measured in a light chamber and, the greater distortion of light indicates a greater particulate content. 

This is then calculated to a reading by the emission analyzer.

A diesel test uses the Plate value for the individual vehicle, and this can be found on the vehicle chassis plate.

The plate value is the manufacturer’s data for the level at which the vehicle must be below to pass the emission test.

What is an emission test / Petrol cars?

An emission test is a measurement of a vehicle’s tailpipe to ensure the vehicle does not exceed current testing limits. A petrol Emission test measures the gasses exiting the exhaust and the required reading must be within specified limits for the vehicle

  • CO – Carbon Monoxide – Poisonous Gas
  • HC – Hydrocarbons – Unburnt Fuel
  • Lambda – A calculated measurement – Lambda 1 is the ideal value 

High CO (carbon Monoxide) or High HC (hydrocarbons) and Lambda not within the specified range are reasons for failure.

How to recognize CO2 emissions?

CO2 is a direct link to fuel economy if your vehicle is using more fuel and your KM/Miles per gallon has decreased then it is likely your CO2 output from the exhaust in grams per KM/mile has increased. 

How to pass the emissions test for MOT?

Perfect fuel combustion and good exhaust gas after-treatment system operation are required for a successful MOT test.

Clean the entire fuel system Pre, During, and Post-combustion to effectively reduce vehicle emissions with Wynn’s Pre-emission test treatment: specially developed to give a fast reduction in exhaust emissions to help pass the Emission test, our fastest-acting product for rapidly reducing exhaust emissions and soot to help meet new emission limits and reduce exhaust smoke.

Wynn’s offers also a solution for Commercial Vehicles: Wynn’s Emission Reducer.

Auto Torque has partnered with Garage Wire to bring you all the latest aftermarket news.


Please enter your comment!
Please enter your name here