Euro exhaust emission standards. What are they, how have they changed?


The Euro standards define the exhaust emission limit for new cars on the territory of EU and European Economic Area. The standards vary across different types of vehicles, which is why a passenger car or a train will have their standards defined differently. What is important, the vehicles that exceed the limits cannot be sold in EU and EEA, including in Latvia. How have the exhaust emission standards developed over the years?

History of the Euro exhaust emission standard  

The first emission standard was introduced back in 1993. Since that year, due to development of internal combustion engines, the average emission has changed significantly, which is why one of the tasks of the European Union is to adapt the level of harmful substances in emissions to today’s values. Subsequent limits set out the directions for manufacturers and enforce new requirements, for example since 2017 every model needs to be tested in terms of actual figures on the roads, and not just in laboratory conditions.  

The Euro standards are not the first ones. Even before that, back in the eighties, the first regulation was introduced – R49, which referred to carbon monoxide, hydrocarbons and nitrogen oxide. It was the Euro standards, however, which left a huge impact on the further automotive development and adaptation of engines to the new conditions, including the climate changes.

Euro 1 standard 

It was introduced in 1992. It covered passenger cars and light trucks. These values were way higher than today, but the manufacturers already focused on catalytic converters back then. From that moment, the standards for gases and solid particles created during combustion were significantly elevated. When it comes to nitrogen oxides, it is a difference of whole 98%, and in case of hydrocarbons – 95%, carbon monoxide had to be reduced by 89%, whereas solid particles – by 97%. That’s quite impressive.     

Euro 2 standard 

It was in force until 1997. At the time it applied to passenger cars and vehicles with two and three wheels that used internal combustion engines.     

Euro 3 standard 

These are the limits from 2001. In this case, it was actually not just cars and trucks that had to meet the standards, but also all the vehicles with an internal combustion engine. This is where the first distinction appeared when it comes to the types of engines. Diesels can emit more nitrogen oxides, but the standards for carbon monoxide are more strict.     

Euro 4 standard 

It was introduced in 2006. It applied to all vehicles, including two- and three-wheelers, but if a car had a gasoline engine for example, it was exempted from the limits on solid particle emissions.     Euro 5 standard The standard from January 2011. It covers light passenger and utility cars as well as two- and three-wheelers. Upon its introduction, manufacturers started equipping cars with solid particle filters, which has a significant impact on their emission during the drive.     

Euro 6 standard 

It has been in force since 2014 to this day. Passenger cars and utility cars have to comply with its limits, which get updated, however.     

Euro 6c standard 

A modification from September 2019. It was another tightening of the limits.     

Euro 6d standard First it was introduced temporarily, then the EU adopted the current version. The temporary Euro 6D specifies in detail how emission tests are to be conducted.     

Euro 7 standard 

So far, the European Commission has not responded about when they will introduce new limits. A lot is pointing to emission reduction being very problematic or impossible without electric cars becoming widespread, and minor differences won’t make legitimate changes.     

How to check the Euro exhaust emission standard in a car? 

Technically speaking, the vehicle license or registration should include information on the standards. If you wish to find out whether your car meets the limits set by the European Commission, it’s a good idea to get a diagnostic test. It is particularly important if you’re importing a car from aboard. The test is referred to as NEDC and it determines the emissions very accurately. At the same time it is worth noting that the prices might be high. You can also check vehicle VIN number and you will find out what EURO your vehicle has. 

Exhaust emission test at a diagnostic station 

For a few years now, there have been announcements of implementing obligatory tests at diagnostic stations during inspections. The main goal is to prevent removal of solid particle filters from cars and deactivation of EGR valves. Although these are illegal and harmful modifications, they remain completely unpunished due to the fact that diagnostic stations rarely check the emissions. It can be performed using a opacimeter, though. It is not the kind of test that would allow to reliably check all the values, though, as it’s more like an optical test rather than a quantitative and qualitative evaluation.  

The absence of a solid particle filter can be noticed, but only when clear signs of tampering are visible, like by putting a regular pipe in that place. Currently it is even possible to reprogram the central unit so that it doesn’t show absence of the filter. The Dieselgate scandal from a few years back, however, shows the necessity to introduce advanced diagnostic tests during inspections and such novelization should be expected in a relatively near future. It requires significant financial fundings from the state budget, but it is necessary to bear such costs for the sake of environment.