Emission requirements for light road vehicles have existed in the EU since the early 1970s, while the first requirements for heavy vehicles came in at the end of the 1980s. They have been tightened up several times over the years, a process that is still going on. The legislation has also been extended to include non-road vehicles and machinery, as well as two- and three-wheeled vehicles. Today, vehicle emissions are controlled under three basic frameworks: the “Euro standards” for traditional air pollutants, the carbon dioxide standards and the vehicle fuel quality standards.
EU’s exhaust emission requirements regulate a number of traditional air pollutants: nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO) and particulate matter (PM). The first binding limits for emissions of the greenhouse gas carbon dioxide (CO2) were only agreed in 2009 (443/2009), when the EU set a legally binding CO2 standard for new cars, and in May 2011 a similar EU legislation for vans was passed (510/2011).
The light category of vehicles covers road vehicles under 3.5 tonnes, i.e. both passenger cars and light commercial vehicles, and standards may vary depending on the type of fuel used (e.g. petrol or diesel), and on the type of vehicle.
Under the Euro 4 standards (that took effect for new vehicles as from 2005) diesel vehicles were allowed to emit around three times more nitrogen oxides than petrol vehicles. Emissions of PM from petrol vehicles were not regulated under Euro 4, since these were then considered to be very low compared to emissions from diesel engines.
The most recently adopted emission regulation dates back to December 2006 (715/2007) and established the currently applicable Euro standards. The Euro 5 standards apply from 2009 for new models and from 2010 for all new vehicles, and the slightly tougher Euro 6 standards apply from 2014 for new models and from 2015 for all new vehicles.
The main effect of Euro 5 is to reduce the emission of particulate matter from diesel cars from 25 to 5 mg/km. Euro 6 will mainly reduce the emissions of NOx from diesel cars further, from 180 to 80 mg/km. The Euro 5/6 legislation also introduces a particle number (PN) emission limit in addition to the mass-based limits.
To get type approval, cars' emissions of air pollutants and CO2 are measured in laboratories using a drive-cycle test-procedure. From around year 2000 until 2017, the test procedure has been using a test cycle known as NEDC, which has been strongly criticized for not properly reflecting real-world driving conditions. In combination with "cycle-beating" this has resulted in real-world emissions being much higher than anticipated, in particular for NOx emissions from diesel-driven cars. As of 1 September 2017, new car models will have to pass new and improved emissions tests in real driving conditions ("Real Driving Emissions" – RDE) as well as an improved laboratory test ("World Harmonised Light Vehicle Test Procedure" – WLTP).
For a more detailed description of the emission standards, the durability requirements and the test cycles used, see AirClim factsheet.
The new Euro standards for nitrogen oxides (NOx) and particulate matter (PM) from passenger cars. Emissions in mg/km. There are also standards for hydrocarbons (HC) and for particle number (PN), but these are not included in the table.
|NOx – diesel cars||250||180||80|
|NOx – petrol cars||80||60||60|
|PM – all cars||251||5||5|
1 Diesel cars only.
The legislation currently in force for heavy-duty vehicles is Directive 2005/55/EC and Directive 2005/78/EC (implementing provisions). This legislation defines the emission standard under Euro IV (applicable from October 2005) and Euro V (applicable as from October 2008). In addition, it defines a non-binding standard called Enhanced Environmentally-friendly Vehicle (EEV).
The most recent legislation (595/2009) was adopted in 2009, and establishes Euro VI standards for the heavy-duty road vehicles that will apply from January 2013. The new standards entail a reduction of 80 per cent in nitrogen oxides (NOx) and 66 per cent in particulate matter (PM) emissions compared to the Euro V limits. The Euro VI standards also introduced particle number (PN) emission limits, stricter OBD requirements and a number of new testing requirements—including off-cycle and in-use testing.
Euro VI means that diesel particulate filters (DPF) must be fitted to all diesel vehicles in order to meet the tougher PM requirement, and exhaust gas recirculation (EGR) and after-treatment devices (such as selective catalytic reduction, SCR) become necessary to meet the new NOx standard.
For a more detailed description of the emission standards, the durability requirements and the test cycles, see AirClim factsheet.
Table: EU emission standards for heavy road vehicles. There are also standards for particle number (PN) carbon monoxide (CO) and ammonia (NH3), and special standards for methane (CH4) for gas-driven vehicles, but these are not included in the table.
|NOx (g/kWh)||HC (g/kWh)||PM (mg/kWh)|
|Euro I (1992-93)||8.0||1.23||360|
|Euro II (1995-96)||7.0||1.1||150|
|Euro III (2000)||5.01||0.662||100/1603|
|Euro IV (2005/06)||3.51||0.462||20/30|
|Euro V (2008/09)||2.01||0.462||20/303|
|Euro VI (2013)||0.4||0.132||10|
1 Both ESC and ETC test cycle.
2 ESC test cycle only.
3 ESC and ETC test cycle respectively.
Emission standards for the Non-Road Mobile Machinery (NRMM) sector were first adopted in 1997 and then revised in 2004. The mother directive (97/68/EC) covers diesel fuelled engines used in excavators, bulldozers, front loaders, back loaders, compressors, etc. The second directive (2002/88/EC) covers spark ignited engines up to 18 kW for engines installed in handheld and non-handheld equipment.
The third directive (2004/26/EC) covers diesel-fuelled engines from 19 to 560 kW for common types of NRMM and regulates the emission in three further stages. The directive also includes railcars and locomotives and inland waterway vessels, and for the two latter categories there are no upper limits concerning engine power. The different stages in the third directive are as follows:
- Stage III A covers engines from 19 to 560 kW including constant speed engines, railcars, locomotives and inland waterway vessels – from January 2006.
- Stage III B covers engines from 37 to 560 kW including, railcars and locomotives – from January 2011.
- Stage IV covers engines between 56 and 560 kW – from January 2014.
Due to the lack of stringency of the emission limit values so far adopted for the NRMM sector in comparison to those of heavy duty vehicles (which often has very similar engines), the relative contribution from the NRMM sector to total emissions is gradually increasing.
A revision of the emission standards for NRMM was originally due in 2007, but was repeatedly postponed. Eventually, in September 2014, the Commission published a proposal to revise the NRMM legislation, including among others new stage V emission standards. In 2015 and 2016, the proposal was discussed in the Parliament and the Council, and an agreement was reached in April 2016. The new Regulation 2016/1628 was adopted in September 2016.
The quality of fuels, especially the sulphur content, is important to regulate in order to achieve low emissions from vehicles. Legislation on the quality of petrol and diesel fuels was passed in 1998 (98/70/EC), and this directive sets maximum levels on sulphur, lead and aromatics allowed in the fuels. In the latest amendment (2009/30/EC) the maximum sulphur content was lowered from 50 to 10 parts per million (ppm) – a level that was seen as a technical prerequisite for the use of PM filters needed to meet the stiffer requirements for PM in the Euro 5 standards.
Fuel suppliers are also required to gradually reduce life cycle greenhouse gas emissions by at least six per cent per unit of energy supplied by the end of 2020 compared with the average levels in 2010. This reduction should be achieved through the use of biofuels, alternative fuels and reductions in flaring and venting at production sites.
The EU has also decided on targets for the use of renewable fuels in the EU. Directive 2003/30/EC requires each country to ensure that biofuels will have replaced two per cent of diesel and petrol by December 2005, and 5.75 per cent by December 2010. Exemption may be granted in cases where there is little potential for producing biofuel, or if it is already being used for other purposes.
A new target was set by the European Council in March 2007 - renewable fuels should supply 10 per cent of energy needs in the transport sector by 2020. This target was also included in the climate and energy package proposal from the Commission in January 2008.
>> Further reading
Diesel - The true (dirty) story (September 2017). Report by T&E.
New diesel cars still emit up to 15 times too much NOx. Article in Acid News 4/2016.
Stricter air pollution rules for machinery agreed. Article in Acid News 2/2016.
Explaining vehicle emissions. Article in Acid News 1/2016.
Diesel cars will continue to exceed emission limits. Article in Acid News 4/2015.
Dirty diesel cars tested. Article in Acid News 3/2015.
NRMM: Low in ambition, late in timing. Article in Acid News 4/2014.
Many loopholes in testing system. Article in Acid News 4/2014.
Diesel cars not as green as perceived. Article in Acid News 2/2014.
Roadmap for less-polluting vehicles. Article in Acid News 4/2013.
EU emission standards for light and heavy road vehicles. Factsheet from AirClim, January 2012.
Transport key to meeting environmental targets. Article in Acid News 4/2011.
Potential cuts in the non road sector. Article in Acid News 2/2011.
Heavy-Duty Vehicle Emissions. The International Council on Clean Transportation (ICCT)
Nonroad Vehicle Emissions Requirements Around the World: A 2005 Status Report. By Michael P. Walsh (pdf, 236 kB)
Transport & Environment (T&E). Environmental organisation active on transport issues