Emissions Testers

Emissions testers are machines responsible for ensuring that vehicles meet emissions standards. They test the emissions of vehicles, collect data, and report the results to the garage and DVLA as part of the MOT. They are used by garage mechanics and MOT Bay engineers, vehicle manufacturers, and vehicle testing facilities.

As part of the DVSA rollout of connected MOT equipment, from 1 May 2021, exhaust gas analysers and diesel smoke meters have been able to connect directly to the MOT testing service, and for any new MOT Bay or an MOT Bay under new ownership, the Emissions Tester has to be connected.

The goal of an emission test is to help reduce the number of harmful pollutants in the environment, in order to lower the overall impact humans have on the planet.

An emission test is an important measure in determining the number of air pollutants that are emitted from the exhaust of a motor vehicle. The pollutants are measured against standards set by the government to ensure that they are within acceptable limits. If the levels of pollutants are too high, the vehicle may be required to undergo repairs or retrofitting in order to reduce the emissions. The emission test is important to help keep the air clean and protect the environment.

Most vehicles have their exhaust emissions tested as part of the annual MOT in the UK.

Usually, the emissions are tested using an emissions tester also known as a gas analyser.

According to the DVSA, petrol vehicles used before August 1975 and diesel vehicles used before January 1980 are tested by sight only.

If a vehicle fails the emission test as part of the MOT then it is deemed to be unroadworthy. The problem must be rectified before the test can be re-done, and upon passing, the valud MOT certificate can be issued.

The only vehicles that do not have an emissions test as part of the MOT are:
vehicles with fewer than 4 wheels
vehicles with 2-stroke engines
hybrid vehicles
quadricycles
hydrogen fuel cell vehicles
electric vehicles