EU: Light-duty: Emissions

Overview

 * Standard type: Conventional pollutant emission limits
 * Regulating body: European Union (European Commission, Parliament, Council, and Member States)
 * Current standard: Euro 5b
 * Future standards: Euro 6 in September 2014
 * Applicability: All vehicles in categories M1, M2, N1 and N2 with a reference mass not exceeding 2610 kg

History
From 1970 until 2006 (through Euro 4), emissions regulations for new light duty vehicles were specified in Directive 70/220/EEC (plus numerous amendments). Beginning with Euro 5 (adopted in 2009), standards have been issued by direct Regulations, which are directly enforceable in all Member States, as opposed to Directives, which must be transposed into each individual Member State. The light-duty Euro standards are referred to using Arabic numerals, e.g. Euro 1, 2, ... 6. Standards vary depending on vehicle fuel type and vehicle size, and include passenger cars and light commercial vehicles.

The regulatory timeline for adoption of EU light-duty vehicle emission standards is as follows:

EU vehicle emission regulations are transposed into UNECE regulations: ECE R 83/01-06.

Euro 1-6
EU emission limits for each standard are summarized in the following tables. All dates listed in the tables refer to new type approvals. The EC Directives also specify a second date—one year later, unless indicated otherwise—which applies to first registration (entry into service) of existing, previously type-approved vehicle models.

Testing
Emissions are tested over the New European Driving Cycle (NEDC) (ECE 15 + EUDC) chassis dynamometer procedure. Effective in 2000 with the Euro 3 standard, the test procedure was modified to eliminate the 40 s engine warm-up period before the beginning of emission sampling. This modified cold start test is referred to as the NEDC or as the MVEG-B test. All emissions are expressed in g/km.

The Euro 5/6 implementing legislation introduces a new PM mass emission measurement method (similar to the US 2007 procedure) developed by the Particulate Measurement Programme (PMP) and adjusts the PM mass emission limits to account for differences in results using the old and the new method. The Euro 5b legislation also introduces a particle number (PN) emission limit in addition to the mass-based limits. Because gasoline direct injection engines have gained relevance, a particle number emission limit for gasoline vehicles is to be defined by September 2014, when Euro 6 is implemented.

Fuel Quality
The Euro 3 and Euro 4 standards were preceded by the introduction of more stringent fuel regulations that required a minimum diesel cetane number of 51 (year 2000), maximum diesel sulfur content of 350 ppm in 2000 and 50 ppm in 2005, and maximum petrol (gasoline) sulfur content of 150 ppm in 2000 and 50 ppm in 2005. “Sulfur-free” diesel and gasoline fuels (&le; 10 ppm S) must be available from 2005, and became mandatory from 2009.

Key Features
 Euro 1 and 2

Euro 1 standards (also known as EC 93), were mandated under Directive 91/441/EEC, for passenger cars only. They were then updated under Directive 93/59/EEC to include both passenger cars and light trucks. Euro 2 standards were mandated under EC 96: Directives 94/12/EC or 96/69/EC.

 Euro 3 and 4 

Euro 3 and 4 standards were mandated under Directive 98/69/EC, with further amendments added under Directive 2002/80/EC. Euro 3 added NOx-specific limits in addition to HC+NOx limits. Positive ignition vehicles were exempted from PM standards through the Euro 4 stage.

In Europe, diesel oxidation catalysts (DOCs) were widely used to comply with Euro 3 and Euro 4 standards. A DOC is a flow-through device that replaces the muffler and makes use of precious metals to oxidize carbon monoxide (CO), gaseous hydrocarbons (HC), and liquid hydrocarbon particles (unburned fuel and oil). DOCs reduce overall PM mass and many toxic organic compounds but are not as effective as catalyzed diesel particle filters in controlling the large number of fine and ultra-fine particles in diesel exhaust.

 Euro 5 and 6 

For diesel engines, Euro 5 has two sets of limits scheduled for implementation: Euro 5a and Euro 5b. For gasoline engines, there is only one set of standards, referred to as Euro 5. Implementation of Euro 5 and Euro 5a began in September 2009. Euro 5b went into effect in 2011.

Euro 5b legislation included, for the first time, a PN emission limit of 6.0×1011/km to the mass-based limits for compression ignition engines established in Euro 5a. Euro 5 improves on Euro 4 by focusing on particulate matter from diesel cars. Euro 5 requires particle filters for diesel cars and mandates PM emissions be reduced to 5 mg/km.

In September of 2014, Europe will introduce Euro 6 standards. An impact assessment by the European Commission found that the stricter NOx requirements in Euro 6 will increase health benefits by 60-90 percent over Euro 5. Euro 6 requires the same PN limit for CI engines as does Euro 5b. The same PN emission limit for diesel vehicles will apply to gasoline vehicles as well when Euro 6 goes into effect.

For both Euro 5 and 6, Regulation 715/2007 served as the EU's “political” legislation, while Regulation 692/2008 was the official “implementing” legislation. These regulations introduce PM mass emission standards, equal to those for diesels, for positive ignition vehicles with DI engines. In order to meet Euro 5 and 6 particle number standards, diesel-fueled vehicles will need diesel particulate filter (DPF) technology. Both gasoline and diesel vehicles will need lower sulfur fuels available for refueling, as well. To achieve the required emission reductions, fuel will need to be 50-ppm sulfur at the least, although 10-ppm sulfur fuel is recommended for better emission reduction performance.

Technology
The following figures, from the International Council on Clean Transportation summarize the major technologies required to meet each stage of Euro emission limits.

Technologies required for compliance: Gasoline

Technologies required for compliance: Diesel

Regulatory Documents
Historical library of EU emission regulations 1970-2003, Directive 70/220/EEC

Euro 1 standards (also known as EC 93), Directive 91/441/EEC
 * Amendment, Directive 93/59/EEC

Euro 2
 * Directives 94/12/EC
 * 96/69/EC

Euro 3 and 4, Directive 98/69/EC
 * Amendment, Directive 2002/80/EC

Euro 5/6
 * “Political” legislation, Regulation 715/2007
 * “Implementing” legislation, Regulation 692/2008
 * Summary page of Euro 5 and Euro 6