Emissions

Reducing emissions from road transport is seen as an important factor in the improvement of air quality

Testing of Emissions at the NCT  & CVT

All cars undergoing the National Car Test (NCT) or Commercial Vehicles Test (CVT) are subjected to exhaust emissions testing measuring the levels of certain gases or of particulates (in the case of diesel engines) emitted by the vehicle under defined test conditions. Vehicles may be tested at varying engine RPM depending on the year of manufacture, the manufacturer’s specifications and the type of engine.

You can learn more about emissions testing requirements in our Vehicle testing section.

Emissions Standards

European emission standards define the acceptable limits for exhaust emissions of new vehicles sold in EU member states. The emission standards are defined in a staged series of EU directives of increasingly stringent standards. Non-compliant vehicles cannot be sold in the EU, but new standards do not apply to vehicles already on the roads.

Different standards apply for each vehicle type. Manufacturers must demonstrate compliance with these standards by running the engine at a standardised test cycle. The use of specific technologies is not mandated, though available technology is considered when setting the standards. New vehicle models introduced must meet current or planned standards, but minor lifecycle model revisions may continue to be offered with pre-compliant engines.

See below our information notes:

Euro IV, Euro V and Euro VI emissions regulations for heavy duty vehicles (PDF)

Euro 5 and Euro 6 emissions regulations for light passenger commercial vehicles (PDF)

Requirements for vehicles to comply with Worldwide Harmonised Light-duty Vehicles Test Procedure (WLTP)


Low Emission Zones

Low and zero emission zones are areas which limit vehicles with higher emissions.

See FAQ document on low emission zones (LEZ) here.

Adblue

In recent years, EU requirements have been brought in to reduce the harmful pollutants being released from diesel engines. Adblue is an aqueous urea-based solution that is stored in a dedicated tank and injected into the exhaust stream of a diesel engine to lower harmful emissions. Adblue is now required to be added to all new diesel engines.

See FAQ document on Adblue here  

Diesel Particulate Filters

Diesel Particulate Filters are fitted in exhaust systems of diesel vehicles helping to reduce harmful emissions into the atmosphere.

See FAQ document on Diesel Particulate Filters here