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Emission Standards

EU: Cars and Light Trucks

Background

European Union emission regulations for new light duty vehicles (passenger cars and light commercial vehicles) were once specified in Directive 70/220/EEC with a number of amendments adopted through 2004. In 2007, this Directive was repealed and replaced by Regulation 715/2007 (Euro 5/6) [2899]. Some of the important regulatory steps implementing emission standard for light-duty vehicles were:

  • Euro 1 standards (also known as EC 93): Directives 91/441/EEC (passenger cars only) or 93/59/EEC (passenger cars and light trucks)
  • Euro 2 standards (EC 96): Directives 94/12/EC or 96/69/EC
  • Euro 3/4 standards (2000/2005): Directive 98/69/EC, further amendments in 2002/80/EC
  • Euro 5/6 standards (2009/2014): Regulation 715/2007 (“political” legislation) [2899] and several comitology regulations

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Applicability. Emission standards for light-duty vehicles are applicable to all vehicles category M1, M2, N1 and N2 with a reference mass not exceeding 2610 kg (Euro 5/6). EU regulations introduce different emission limits for compression ignition (diesel) and positive ignition (gasoline, NG, LPG, ethanol,...) vehicles. Diesels have more stringent CO standards but are allowed higher NOx. Positive ignition vehicles were exempted from PM standards through the Euro 4 stage. Euro 5/6 regulations introduce PM mass emission standards, equal to those for diesels, for positive ignition vehicles with DI engines.

EU Member States may introduce tax incentives for early introduction of vehicles that comply with future emission standards.

Fuels. The 2000/2005 standards were accompanied by an introduction of more stringent fuel regulations that require 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 (≤ 10 ppm S) had to be available from 2005, and became mandatory from 2009.

Emission Testing. Emissions are tested over the Worldwide harmonized Light vehicles Test Cycle (WLTC) chassis dynamometer procedure, which is replacing the earlier NEDC test. Real Driving Emissions (RDE) testing requirements are phased-in from 2017 to control vehicle emissions in real operation, outside of the laboratory emission test.

Emission Standards

EU emission standards 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.

Table 1
EU emission standards for passenger cars (Category M1*)
Stage Date COHCHC+NOxNOxPMPN
g/km#/km
Positive Ignition (Gasoline)
Euro 1† 1992.07 2.72 (3.16)-0.97 (1.13)---
Euro 2 1996.01 2.2-0.5---
Euro 3 2000.01 2.300.20-0.15--
Euro 4 2005.01 1.00.10-0.08--
Euro 5 2009.09b 1.00.10d-0.060.005e,f-
Euro 6 2014.09 1.00.10d-0.060.005e,f6.0×1011 e,g
Compression Ignition (Diesel)
Euro 1† 1992.07 2.72 (3.16)-0.97 (1.13)-0.14 (0.18)-
Euro 2, IDI 1996.01 1.0-0.7-0.08-
Euro 2, DI 1996.01a 1.0-0.9-0.10-
Euro 3 2000.01 0.64-0.560.500.05-
Euro 4 2005.01 0.50-0.300.250.025-
Euro 5a 2009.09b 0.50-0.230.180.005f-
Euro 5b 2011.09c 0.50-0.230.180.005f6.0×1011
Euro 6 2014.09 0.50-0.170.080.005f6.0×1011
* At the Euro 1..4 stages, passenger vehicles > 2,500 kg were type approved as Category N1 vehicles
† Values in brackets are conformity of production (COP) limits
a. until 1999.09.30 (after that date DI engines must meet the IDI limits)
b. 2011.01 for all models
c. 2013.01 for all models
d. and NMHC = 0.068 g/km
e. applicable only to vehicles using DI engines
f. 0.0045 g/km using the PMP measurement procedure
g. 6.0×1012 1/km within first three years from Euro 6 effective dates
Table 2
EU emission standards for light commercial vehicles
Category† Stage Date COHCHC+NOxNOxPMPN
g/km#/km
Positive Ignition (Gasoline)
N1, Class I
≤1305 kg
Euro 1 1994.10 2.72-0.97---
Euro 2 1998.01 2.2-0.50---
Euro 3 2000.01 2.30.20-0.15--
Euro 4 2005.01 1.00.10-0.08--
Euro 5 2009.09b 1.00.10g-0.060.005e,f-
Euro 6 2014.09 1.00.10g-0.060.005e,f6.0×1011 e,j
N1, Class II
1305-1760 kg
Euro 1 1994.10 5.17-1.40---
Euro 2 1998.01 4.0-0.65---
Euro 3 2001.01 4.170.25-0.18--
Euro 4 2006.01 1.810.13-0.10--
Euro 5 2010.09c 1.810.13h-0.0750.005e,f-
Euro 6 2015.09 1.810.13h-0.0750.005e,f6.0×1011 e,j
N1, Class III
>1760 kg
Euro 1 1994.10 6.90-1.70---
Euro 2 1998.01 5.0-0.80---
Euro 3 2001.01 5.220.29-0.21--
Euro 4 2006.01 2.270.16-0.11--
Euro 5 2010.09c 2.270.16i-0.0820.005e,f-
Euro 6 2015.09 2.270.16i-0.0820.005e,f6.0×1011 e,j
N2 Euro 5 2010.09c 2.270.16i-0.0820.005e,f-
Euro 6 2015.09 2.270.16i-0.0820.005e,f6.0×1011 e,j
Compression Ignition (Diesel)
N1, Class I
≤1305 kg
Euro 1 1994.10 2.72-0.97-0.14-
Euro 2 IDI 1998.01 1.0-0.70-0.08-
Euro 2 DI 1998.01a 1.0-0.90-0.10-
Euro 3 2000.01 0.64-0.560.500.05-
Euro 4 2005.01 0.50-0.300.250.025-
Euro 5a 2009.09b 0.50-0.230.180.005f-
Euro 5b 2011.09d 0.50-0.230.180.005f6.0×1011
Euro 6 2014.09 0.50-0.170.080.005f6.0×1011
N1, Class II
1305-1760 kg
Euro 1 1994.10 5.17-1.40-0.19-
Euro 2 IDI 1998.01 1.25-1.0-0.12-
Euro 2 DI 1998.01a 1.25-1.30-0.14-
Euro 3 2001.01 0.80-0.720.650.07-
Euro 4 2006.01 0.63-0.390.330.04-
Euro 5a 2010.09c 0.63-0.2950.2350.005f-
Euro 5b 2011.09d 0.63-0.2950.2350.005f6.0×1011
Euro 6 2015.09 0.63-0.1950.1050.005f6.0×1011
N1, Class III
>1760 kg
Euro 1 1994.10 6.90-1.70-0.25-
Euro 2 IDI 1998.01 1.5-1.20-0.17-
Euro 2 DI 1998.01a 1.5-1.60-0.20-
Euro 3 2001.01 0.95-0.860.780.10-
Euro 4 2006.01 0.74-0.460.390.06-
Euro 5a 2010.09c 0.74-0.3500.2800.005f-
Euro 5b 2011.09d 0.74-0.3500.2800.005f6.0×1011
Euro 6 2015.09 0.74-0.2150.1250.005f6.0×1011
N2 Euro 5a 2010.09c 0.74-0.3500.2800.005f-
Euro 5b 2011.09d 0.74-0.3500.2800.005f6.0×1011
Euro 6 2015.09 0.74-0.2150.1250.005f6.0×1011
† For Euro 1/2 the Category N1 reference mass classes were Class I ≤ 1250 kg, Class II 1250-1700 kg, Class III > 1700 kg
a. until 1999.09.30 (after that date DI engines must meet the IDI limits)
b. 2011.01 for all models
c. 2012.01 for all models
d. 2013.01 for all models
e. applicable only to vehicles using DI engines
f. 0.0045 g/km using the PMP measurement procedure
g. and NMHC = 0.068 g/km
h. and NMHC = 0.090 g/km
i. and NMHC = 0.108 g/km
j. 6.0×1012 1/km within first three years from Euro 6 effective dates

Emission Testing

Test Procedures. Emissions are tested over a chassis dynamometer test cycle and expressed in g/km (except PN, which is expressed in 1/km). Over the time, there have been several changes to the regulatory emission test cycles:

  • ECE 15 + EUDC: The original EU test cycle (also known as the MVEG-A test), including urban and extra-urban segments, performed from a hot start.
  • NEDC: Effective from 2000 (Euro 3), the ECE 15 + EUDC test was modified to eliminate the 40 s engine warm-up period before the beginning of emission sampling. This modified cold start test was referred to as the New European Driving Cycle (NEDC) or as the MVEG-B test.
  • WLTP: The Worldwide harmonized Light vehicles Test Procedure (WLTP) and the corresponding Test Cycle (WLTC) [3635][3636] replaced the NEDC procedure. The transition from NEDC to WLTC occurs over the following schedule:
    • September 2017—WLTP type approval testing is introduced for new car types. Cars approved using the old NEDC test can still be sold.
    • September 2018—All new vehicles must be certified according to the WLTP test procedure.
    • January 2019—All cars at dealerships should have WLTP-CO2 values only (with some exceptions for a limited number of vehicles in stock). National governments should adjust vehicle taxation and fiscal incentives to WLTP values.

During the transition period, compliance with the existing NEDC-based CO2 targets is determined using the CO2MPAS correlation tool. In the 2020 timeframe, European Commission will convert the NEDC-based CO2 targets to WLTP targets of comparable stringency.

The Euro 5/6 implementing legislation introduced new PM and PN emission measurement methods developed by the UN/ECE Particulate Measurement Programme (PMP). The new PM mass measurement method is similar to the US 2007 procedure. The regulatory PM mass emission limits were adjusted to account for differences in results using the old and the new method. PN emissions are measured over the NEDC/WLTC test cycle using the PMP particle number method [UN/ECE Reg. 83 Suppl. 7].

Real Driving Emissions (RDE). In addition to laboratory testing, vehicle emissions must be tested on the road. The RDE testing requirements have been introduced through several regulatory amendments, with the first RDE package published in March 2016 [3362], the second in April 2016 [3638] and the third in July 2017 [3637]. The RDE test is performed during vehicle operation using a portable emissions monitoring system (PEMS). The RDE test must last from 90 to 120 minutes. The route must include three segments: urban (< 60 km/h), rural (60-90 km/h) and motorway (> 90 km/h), in that order and with respective shares of one third. Each segment must cover a distance of at least 16 km.

NOx emissions must be measured on all Euro 6 vehicles (passenger cars and light-commercial vehicles). On-road PN emissions are to be measured on all Euro 6 vehicles which have a PN limit set (diesel and GDI). CO emissions also have to be measured and recorded on all Euro 6 vehicles. PEMS data must be processed using two methods: the CO2 moving average window (EMROAD) and the power binning (CLEAR). RDE emission limits are defined by multiplying the respective NEDC emission limit by a conformity factor for a given emission.

RDE testing requirements are introduced in phases:

  1. RDE monitoring phase—Still without conformity factors, enters into force for new type approvals on April 20, 2016.
  2. RDE type approval testing—RDE conformity factors are phased-in as follows:
    • NOx conformity factors:
      • 2.1 from September 2017 for new models and from September 2019 for all new vehicles
      • 1.5 from January 2020 for new models and from January 2021 for all new vehicles
    • PN conformity factor: 1.5 from September 2017 for new models and from September 2018 for all new vehicles (one year later to both dates for N1 Class II and III and N2 vehicles)
  3. RDE In-Service Conformity requirements are expected to be adopted in the fourth RDE package.

Defeat Devices. For light-duty vehicles, EU regulations define a ‘defeat device’ as:

any element of design which senses temperature, vehicle speed, engine speed (RPM), transmission gear, manifold vacuum or any other parameter for the purpose of activating, modulating, delaying or deactivating the operation of any part of the emission control system, that reduces the effectiveness of the emission control system under conditions which may reasonably be expected to be encountered in normal vehicle operation and use;

The regulations prohibit defeat devices but provide situations under which the prohibition does not apply. This allows manufacturers the option of disabling emission control system components to protect the engine/vehicle and to facilitate starting. However, the regulations do not clearly define ‘emission control system’, a critical aspect of the defeat device definition. A definition is given in the context of the OBD system as:

the electronic engine management controller and any emission-related component in the exhaust or evaporative system which supplies an input to or receives an output from this controller

It is important to note that this definition does not include features such as fuel system parameters, combustion system design and the EGR system.

EU regulations are unclear on how manufacturers are required to apply for an exemption to the defeat device prohibition.