Timeline: EEA Report References to Real World Emissions and Euro Standard Discrepancies
Timeline: EEA report references to real world emissions and Euro standard discrepancies
European Environment State and Outlook Reports(SOER): SOER 2005, SOER2010 air pollution fiche, SOER2015 synthesis (translated) and Part B transport
TERM reports: 2004 (CO2 and NOx), 2005, 2006, 2007, 2008, 2011, 2012, 2013, 2014, 2015
Air Quality in Europe reports: 2011, 2012, 2013, 2014, 2015
NEC Directive Status reports: published in 2010, 2011, 2012, 2014, 2015
Cars and vans CO2 monitoring: 2014 (Apr and Oct), 2015 (Apr and Nov), 2016 (Apr)
Policy evaluation and other: EEA Signals 2013 – Every breath we take; Road user charges for heavy goods vehicles (HGV) 2013; Evaluation of progress under the EU National Emission Ceilings Directive 2012, Projections in hindsight 2015.
Date / Publication / DescriptionOct
2004 / TERM 2004 p10 / There is, however, increasing evidence that standardised test cycles used for the type approval of vehicles do not necessarily represent real world driving conditions. The issue of 'chip-tuning' of diesel vehicles to boost power at the expense of fuel consumption and low emissions is a cause for concern (Danish Miljøstyrelsen, 2004)
Nov 2005 / SOER 2005 p99 / There is also a concern that emissions from transport are not falling as quickly as expected due to test cycles not reflecting real-world driving conditions, the chip-tuning of diesel cars and other non-combustion emission sources (brakes, car tyres) that increase in line with traffic growth and congestion.
Mar
2006 / TERM 2005 p19 / Emission standards do not always offer a correct picture of emissions nor do they lend themselves easily to direct comparison between modes. Firstly, engines are tested with different test cycles that put different stresses on the engines. Even though test cycles are approximations of real-world loads on engines, they will inevitably have shortcomings.
Feb 2007 / TERM 2006 p19
And similar:
TERM 2007 p19
TERM 2008 p18 / Air quality is affected by a combination of emission and meteorological factors. It is therefore too early to offer solid conclusions on the impact of transport on air quality development in urban areas. However, two elements may help to explain why the improvement still fails to appear: the increased use of diesel in urban areas and an increase of the fraction of NOX emitted as NO2 since 2000. Oxidation catalysts and regenerative traps in modern diesel vehicles have been found to cause the increase (AQEG, 2006)
Sep 2010 / NEC Directive Status report 2009 p5
And similar in 2010 NECD status report (published in 2011), 2011 (2012), 2012 (2013), 2013 (2014) and 2014 (2015) reports / 2009 status report: although overall emissions have decreased since 1990, the reduction has not always been as large as originally anticipated. This is partly because the sector has grown more than expected and partly because vehicle emission standards have not always delivered the foreseen level of NOX reductions
2011 status report: although overall emissions have decreased since 1990, the reduction has not always been as large as originally anticipated. This is partly because the sector has grown more than expected and partly because vehicle emission standards have not always delivered the foreseen level of NOX reductions
2015 status report: Actual emissions from vehicles driven on roads under normal conditions are also higher than originally expected, with 'real-world emissions' often largely exceeding the permitted test-cycle emissions used for certification of vehicles complying with Euro standards. This is particularly true for light-duty diesel vehicles.
Nov 2010 / SOER2010 Air Pollution thematic assessment p24 / Reduced emissions from the road transport sector have occurred despite the general increase in activity within the sector, and have been achieved mainly as a result of fitting catalysts to vehicles, a process driven by the introduction of respective EU standards. It is important to note, however, that a number of NOX vehicle emission standards have not been as effective in reducing real-world NOX emissions as was originally anticipated, especially for diesel vehicles (both passenger vehicles and heavy- and light-duty vehicles). Much of the past reduction in NOX from road transport can thus mainly be ascribed to gasoline passenger cars and not diesel vehicles (Vestreng et al., 2009)
Nov 2011 / TERM 2011
NOx p14 and Box 2.16 p28.
CO2 Section 7.5 and 7.6 p60-61 / The actual emissions from vehicles (often termed 'real-world emissions') may exceed the type-approval emissions for each vehicle type. This is particularly the case for NOX emissions from diesel vehicles. The emission factors used in the emissions inventories by EU Member States have been regularly updated according to new findings. Thus, the reported developments in the emissions presented here should include the 'real-world driving' emission factors as far as is possible.
and
Section 7.5 ‘Laboratory testing versus real-life driving’ presents a discussion of differences between real-world and NEDC testing for CO2, including ‘The assumptions underlying the NEDC do not properly represent actual driving styles of average car users: this is seen in terms of accelerations and speeds, for instance. It is commonly reported in motor magazines that it is difficult to achieve the energy efficiency claimed in advertising of new vehicles, even though the values used are taken from type-approval testing.’ Illustrative CO2 measurements are quoted from a TNO2010 study.
Nov 2011 / Air Quality in Europe 2011 p43 / First AQ in Europe report.
Actual emissions from vehicles (often termed 'real world emissions') may exceed the allowed emissions specified in the Euro emission standards for each vehicle type. This is particularly the case for NOX emissions from light-duty diesel vehicles. EU Member States regularly update the emission factors used in their emission inventories and their previously reported emissions. Reported developments in emissions should therefore include 'real world' emission factors.
Sep 2012 / Air Quality in Europe 2012 p38, 60 / Under real-world driving conditions, emissions from vehicles often exceed the test cycle limits specified in the Euro emission standards (EEA, 2011d). Reported emissions data from countries are based on the best knowledge available concerning real-world emissions. However, the lack of vehicle exhaust measurements, especially for newer vehicle technology types, often means the reported emission estimates are of relatively high uncertainty, and may not always reflect the actual, potentially higher, on-road driving emissions
Oct
2012 / Policy evaluation studies eg ‘Evaluation of progress under the EU National Emission Ceilings Directive’ / Nevertheless, the following examples illustrate some key instances in which new knowledge has led to significant revision of emission estimates. NOX emissions from road transport higher than foreseen under real operating conditions: In order to improve air quality, the pollutant exhaust emissions of road vehicles are limited by regulation. Regulatory limits apply to exhaust emission measurements during vehicle type approval procedures with the New European Driving Cycle (NEDC). Over the last three decades, limit values were lowered in steps from EURO 0 to EURO 5. Further steps have already been defined for the coming years (EURO 6). Air quality, however, has not improved as much as predicted on the basis of the tightening of emissions standards, especially with respect to nitrogen oxides (NOX). One reason for this is the gap between the performance of emission control measures during type approval tests (NEDC) and their effectiveness under real-life urban driving conditions
Nov 2012 / TERM 2012 p32, p35, p55 / In simple terms, the 'euro standards' for vehicle emissions have not succeeded in bringing down real NO2 emissions to the levels set out in the legislation. Further discussion on this disparity can be found in Sections 4.3 and 4.5 and Chapter 5.
4.3 Real-world emission performance of vehicles Under real-world or 'normal' driving conditions, emissions from vehicles often exceed the test cycle limits specified in the Euro emission standards (see Box 2.16 of the TERM 2011 report (EEA, 2011b)). Several studies (Pelkmans and Debal, 2006; VojtisekLom et al., 2009; Rubino et al., 2007; Weiss et al., 2012 ) have indicated that real world NOX emissions of light-duty diesel vehicles might substantially exceed Euro 2–5 emission limits. Tests performed by JRC (Weiss et al., 2011) on passenger cars and light commercial vehicles show that Euro 3–5 diesel vehicles exceed the emission limits by a factor of 2–4 in real world driving. The exceedance can be much higher on sub-sections of individual 'on-road' tests which are comparable in duration to standard laboratory testing with the New European Driving Cycle (NEDC). The exceedance also occurs with heavy duty vehicles (HDV), albeit to a lesser extent (Verbeek et al., 2010). The emission factors used by EU Member States for estimating emissions when developing inventories have been updated to reflect this as far as possible, such as in the COPERT 4 road transport emissions model (Emisia, 2012). There is further evidence from roadside remote sensing of emissions that the divergence could be even greater than indicated by currently available emission factors (Carslaw et al., 2011; Beevers et al., 2012). Roadside remote sensing is a technique which measures the concentration of pollutants in the exhaust plume of every vehicle that passes the sensing equipment. Further remote sensing studies in the Netherlands (Velders et al., 2011) have highlighted the problem with Heavy Goods Vehicles (HGVs) equipped with Selective Catalytic Reduction (SRC) for NOX control. Many HGVs use this technology to meet the Euro V standards, but while it appears effective at high speeds, under low-load urban conditions, the technology is much less efficient due to the low exhaust temperatures making the catalyst ineffective at reducing NOX in the tailpipe. If this technology is used, emissions from Euro V vehicles can therefore actually be higher than the Euro IV equivalents under so called slow urban conditions unless the technology has been optimised (HBEFA, 2010). As a longer term solution, the European Commission is developing new test procedures aimed at more accurately reflecting real world conditions.
Feb 2013 / Road user charges for heavy goods vehicles (HGV) / Actual 'real-world' vehicle emissions differ considerably both from limit values laid down for vehicles in legislation, and from vehicle approval test conditions.
Jul 2013 / EEA Signals – Every breath we take / Another problem in controlling air pollution comes from the difference between laboratory tests and real world conditions
Oct 2013 / Air Quality in Europe 2013 p41,
p62 / Under real-world driving conditions, emissions from vehicles often exceed the test-cycle limits specified in the Euro emission standards (EEA, 2011a).
Actual emissions from vehicles (often termed 'real world emissions') may exceed the allowed test cycle emissions specified in the Euro emission standards for each vehicle type. This is particularly the case for NOX emissions from light-duty diesel vehicles.
Dec 2013 / TERM 2013 Box 4.1 p40 /
Apr 2014 / Monitoring CO2 emissions from passenger cars / Member States report CO2 emission levels determined as part of the type approval test procedure. These levels are measured under laboratory conditions using a legislative driving cycle (i.e. the New European Driving Cycle (NEDC)). This should make the measurements comparable between manufacturers, but not necessarily representative of realworld conditions. In fact, NEDC cycles represent an artificial driving speed pattern with low accelerations, constant speed cruises, and many idling events. As a result, the measured emissions levels can be different from those in real world conditions. The driving cycles influence not only CO2 emissions but also air pollutants, such as NOX. Although not discussed further in this document, differences between test cycle and real world NOX emissions have proved particularly problematic for air quality policy. While vehicle emission standards for NOX have been increasingly strengthened (based on NEDC cycles) in recent years, the reductions from this sector have not been as large as originally anticipated due to the higher realworld emissions that have occurred.
Oct 2014 / Monitoring CO2 emissions from passenger cars and vans in 2013 p6
And all of Chapter 5 (detailed analysis) / In recent years there has been a growing awareness of the need to ensure that emissions measured in the type approval driving cycle better represent 'real-world' driving conditions. In particular, numerous studies have highlighted the often significant divergence between type approval and real-world CO2 emissions. Reflecting this, a substantial effort has been made in EU in recent years to update the current type-approval procedure by introducing the Worldwide harmonized Light vehicles Test Procedure (WLTP) approach that aims to better represent actual vehicle operations on the road. Despite such differences, it is nevertheless clear that real emission reductions have occurred as a result of the introduction of the EU CO2 emission performance standards for light duty vehicles. To illustrate the scope of the potential differences, this report also presents results of an assessment comparing the current reported regulatory 'type-approval' emissions with estimated 'real-world' emissions. Real-world CO2 emissions were estimated based upon a set of models constructed to determine fuel consumption of passenger cars predicted on the basis of independent variables reported by Member States, including the vehicle mass, engine capacity and type-approval CO2 emissions. The main findings of the assessment are:
• EU wide, the real-world to type-approval CO2 emissions ratio for petrol cars is comparable to the one for diesel cars for all vehicle sizes. Looking at the overall petrol and diesel fleet, the ratio is somewhat higher for diesel cars (21 %) than for petrol ones (19 %) because the relative contribution of large cars (with an engine size above 2.0 litres) is higher for diesel than for petrol.
• The CO2 emissions ratio for petrol cars varies from 18 % for small cars to 32 % for large cars, whereas for diesel cars it ranges from 22 % for small cars to 27 % for large cars
Nov 2014 / Air Quality in Europe 2014 p25
Box 5.2 p32 / Actual emissions from vehicles (often termed 'real-world driving emissions') may exceed the allowed test-cycle emissions specified in the Euro emission standards for each vehicle type. This is particularly the case for NOX emissions from light-duty diesel vehicles (EC, 2013a, Williams and Carslaw, 2011). EU Member States regularly update the emission 'factors' (values used to estimate how much of a particular pollutant is present in emissions of a particular type) used in their emission inventories and their previously reported emissions. Reported developments in emissions should therefore include 'real-world' emission factors.
Dec 2014 / TERM 2014 p13,
Box 2.11 p27
p47 / The 2015 target for the average CO2 emissions of new passenger cars was attained in 2013. However, the divergence between fuel consumption and resulting CO2 emissions, when comparing tests against real-world conditions, remains a point of concern.
Numerous studies have documented the often significant divergence between type-approval and real-world CO2 emissions. It appears that there may indeed be an increasing divergence between type-approval and real-world fuel consumption, and hence, CO2 emissions. A recent study (Ntziachristos et al., 2014) suggests that the difference is 11 % for petrol cars and 16 % for diesel cars. The study also stated that the difference can reach 60 % for newer vehicle models registered in the low 90 g CO2/km to 100 g CO2/km category. Another recent report (ICCT, 2014) suggests that the divergence increased from 10 % on average in 2001 to 23 % by 2011, and to more than 30 % in 2013. Despite the difference in CO2 emissions when measured using real-world and type-approval approaches, real emission reductions have occurred as a result of regulations based upon the current type-approval monitoring regime. Using implied emission factors based on total consumption and activity, researchers (Papadimitriou et al., 2014) calculated a 2 % fleet-wide fuel consumption reduction for both diesel and gasoline passenger cars in 2010 compared to 2005. The improved testing method and the increased focus on real world emissions are expected to bring about additional reductions in future.
...this is also the effect of the divergence between vehicle test results and actual on-road vehicle performance for NOX (EEA, 2013a; Weiss et al., 2012) and, for similar reasons, for CO2. For NOX, the divergence also exist in the most modern diesel vehicles. Recent research has estimated that the average on-road emission levels of NOX is seven times the certified emission limit for Euro 6 vehicles, with a few vehicles performing substantially better than others (Franco et al., 2014). As the authors state, the fact that one of the vehicles tested is already compliant with the Euro 6 standard in real driving conditions indicates that the technologies for 'realworld–clean' diesels is already in place.
Mar 2015 / SOER2015 Synthesis report p101 / Alongside increasing traffic volumes, the promotion of diesel vehicles is contributing to air quality problems. This is because diesel cars generally emit more particulate matter and nitrogen oxides than petrol cars but less carbon dioxide, although recent data indicate that the carbon dioxide difference is decreasing (EEA, 2014l). In addition, NOX emissions from diesel vehicles under real-world driving conditions often exceed the test-cycle limits specified in the Euro emission standards, a problem that also affects official fuel consumption and CO2-emission values.
Mar
2015 / SOER2015 Part B Transport fiche / A less positive development is the increase in the fraction of NOxemitted as NO2by diesel vehicles, leading to exceedances of NO2values in many European cities. Increasing traffic volumes, coupled with the promotion of diesel vehicles in many EU Member States, have thus become one of the main reasons why countries do not meet EU air quality regulations.
To make matters worse, NOxemissions from diesel vehicles under real-world driving conditions often exceed the test-cycle limits specified in the Euro emission standards, a problem that also affects official fuel consumption and CO2-emission values. In general, an average diesel car emits more PM and NOXthan petrol, but less CO2. Recent data show that the CO2difference is decreasing.