Vehicle emission classes: what they are and what distinguishes them

Vehicle environmental classes, also known as Euro standards, indicate the level of pollutant emissions produced by a vehicle. They are a key tool for assessing a car’s environmental impact and also determine access to Low Traffic Zones (LTZs), possible driving restrictions, and in many cases the vehicle’s market value.

In this article, we’ll explain what designations such as Euro 3, Euro 4, and Euro 5 mean, which emission classes exist, and what changes with the most recent regulations such as Euro 6 and Euro 6d-Temp.

What do Euro 3, Euro 4, and Euro 5 mean for a car?

The labels Euro 3, Euro 4, and Euro 5 refer to the European emission standards that a vehicle complies with at the time of its type approval.

Each regulation sets increasingly stringent limits on harmful substances such as:

• Nitrogen oxides (NOx)

• Carbon monoxide (CO)

• Unburned hydrocarbons (HC)

• Particulate matter (PM), especially for diesel engines

The higher the number, the cleaner and more modern the vehicle is considered.

For example:

• Euro 3 cars: vehicles produced after January 1, 2001

• Euro 4 cars: vehicles registered between 2006 and 2009

• Euro 5 cars: vehicles registered after September 2009

In practical terms, knowing your car’s emission class helps you understand how much it pollutes and where it is allowed to circulate.

What are the euro emission classes?

To date, the environmental classes for cars and light commercial vehicles are divided as follows:

• Euro 0: vehicles registered before 1993, with no emission regulations

• Euro 1: vehicles registered between 1993 and 1995

• Euro 2: vehicles registered between 1996 and 1999

• Euro 3: vehicles registered between 2000 and 2004

• Euro 4: vehicles registered between 2005 and 2010

• Euro 5: vehicles registered between 2011 and 2014

• Euro 6: vehicles registered from 2015 onwards, with several subcategories:

  • Euro 6a

  • Euro 6b

  • Euro 6c

  • Euro 6d-Temp

  • Euro 6-Temp

These subcategories define new particulate emission limits based on the vehicle’s year of registration.

Starting from July 1, 2025, Euro 7 standards have been introduced for light-duty vehicles. These standards are part of the European Union’s roadmap to eliminate all CO₂ emissions from light vehicles by 2035 and to make Europe climate-neutral by 2050.

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