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All about pollutant classes and their role in environmental protection

Content

1. Different emission standards worldwide

2. How engine design influences the emissions class

3. Which pollutant class does my car have?

4. Effects on vehicle tax and environmental zones

Improved environmental protection and a reduction in pollution are high on the agenda in many countries. Specified pollutant classes for cars guarantee compliance with certain emission limits. You can find all the important information on this topic here.

Different emission standards worldwide

Exhaust emission regulations and the associated pollutant classes exist in numerous parts of the world. In the European Union, for example, there are fixed limits for pollutants such as carbon monoxide, nitrogen oxides, hydrocarbons and particulates. The pollutants contained in the exhaust gas are determined in driving cycles and set per kilometer.

Euro exhaust emission standard such as Euro 5 or Euro 6

The member states of the European Union follow a common line on the subject of pollutant classes. The respective applicable exhaust emission standards in the EU are therefore jointly decided and enforced by the states. In the European Union, there are the pollutant classes Euro 1, Euro 2, Euro 3, Euro 4, Euro 5 and the pollutant class Euro 6. The validity of the pollutant class depends on the initial registration of the vehicles concerned. For example, the Euro 1 standard applied to new vehicles from the date of introduction in January 1993. The Euro 2 emissions standard applied to cars from the beginning of 1996, and Euro 3 applied from 01. Euro 4 applied to new registrations from 2006, followed by Euro 5a in 2011 and the Euro 6 standard from 2015.

Exhaust emission standards in the USA

In the USA, various pollutant classes for vehicles have existed since the 1990s. However, the rules and regulations governing pollutant emissions from passenger cars can vary from state to state. The problem of environmental pollution caused by exhaust gases has been known for a long time, especially in California. In 1994, California introduced the Tier 1 national emissions standard, which was replaced in 2004 by the more stringent Tier 2 standard, and Tier 3 has been in place since 2017. Other states have followed these standards over the years. The limits for some pollutants are set lower in the USA than in Europe. This applies, for example, to the value for nitrogen oxide in diesels.

Standards in other countries

Standards for exhaust emissions from vehicles with internal combustion engines also exist in other parts of the world. In China, for example, there are various pollutant standards for passenger cars as diesel or gasoline engines. The first standard for vehicles became valid in 2008. An exhaust emission regulation valid throughout the country from 2010 was based on the European Euro 4 standard, followed by further standards and classes similar to the European Euro 5a in China from 2013. Regulations based on Euro 6 have been in force since 2020. Countries such as Japan also have their own emissions regulations. The country introduced its first standards in 1994, and these were adapted in 2000. New standards followed in 2005 and 2009, and tests according to WLTP will apply from 2019.

How engine design influences the emissions class

In the development of new vehicles and engines, the focus is increasingly on pollutant emissions and the targeted pollutant class. Among other things, vehicle manufacturers are relying on new technologies in engine design. Optimization of the combustion chambers and the compression ratio, for example, allows pollutant emissions to be reduced. Likewise, variable valve timing or improved charge air cooling can influence exhaust gas behavior. Innovations in the area of engine control also contribute to improved pollutant behavior. These include optimized electronic injection and a matching ignition system with map ignition, or the deactivation of individual cylinders as required. In addition, the treatment of exhaust gases has a decisive influence on the pollutant class. These include exhaust gas recirculation and catalytic converters or particulate filters.

Which pollutant class does my car have?

As a vehicle owner, you are certainly interested in the pollutant class of your own car. It is easy to find out yourself with the help of the vehicle documents. Older vehicles that have been registered for longer bear a corresponding key number in the top left-hand corner of the vehicle registration document. Since 2005, the registration certificate part 1 according to European standards has been used instead of the vehicle registration certificate. The corresponding sequence of numbers is noted there in field 14.1 of the document. The key number for the pollutant emission, which is found in the papers for the vehicle, allows the pollutant class to be determined. In the pollutant classes 1 to Euro 4, the pollutant class can be determined on the basis of the last two digits of the number. From Euro 5 to Euro 6, a longer emission code number is entered. In addition, the pollutant class is noted directly in field 14 of the registration certificate or in field 1 of the old vehicle registration document.

Effects on vehicle tax and environmental zones

The pollutant emissions of passenger cars often have a direct impact on costs associated with the car, such as vehicle tax. There is even the threat of a driving ban in cities if the vehicle does not comply with the emission standards. For example, many German cities have set up environmental zones that require a corresponding environmental badge. Even electric cars with an E-number require such a sticker in order to be allowed to enter the environmental zones. The motor vehicle tax can also depend on the vehicle’s pollutant emissions. In addition to the engine displacement, the exhaust emission standard and compliance with certain CO2 limits also influence the tax amount. Depending on the vehicle and engine, however, emissions and the associated pollutant class classification can be improved. This can be done, for example, by installing a cold-running regulator or retrofitting a catalytic converter.

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