Real Driving Emissions and Test Procedures

As we move towards 2020 and the related emission targets, there remains a level of uncertainty over the test procedures which will be used to determine compliance with the regulations. The EU has stated in the past that new testing protocols could be introduced throughout this year with full implementation by 2017, but as yet, has given manufacturers precious little information on the exact procedures to be used. To add to the concerns, there have been question marks raised over the last few years about the reliability of current test data, the accuracy of emission reduction figures for the last decade, and the potential manipulation of loopholes in test procedures by manufacturers to achieve artificially positive results. It is generally accepted that emission test procedures must be overhauled if the industry is to achieve the targets for 2020 in real driving conditions as well as in the lab; and it appears to have become a race against time to implement not just the legislation, but the technical procedures and equipment required to test for compliance. Real Driving Emissions Overview Several reports recently from organisations such as the Joint Research Council (JRC) and the pressure group Transport and Environment have highlighted the difference between current test results and what is really happening on the road, and the EU has taken steps to address the issues. In 2011 The European commission established the Real Driving Emissions – Light Duty Vehicle (RDE-LDV) working group to assess the potential of two candidate testing procedures: Emission testing with random driving cycles in the laboratory, and on-road emissions testing with Portable Emissions Measuring Systems (PEMS). Image Source: Joint Research Centre The subsequent report published by the JRC recommended the development of test procedures based on on-road testing with Portable Emissions Measuring Systems (PEMS), as the most accurate and reliable testing system to move forward with. The key findings of the report noted that PEMS on-road emissions testing covers a wider range of driving conditions than random cycle testing and is therefore more effective in ensuring emissions are limited during normal operation. However, it also highlighted that random cycle testing retains the advantage of established, accurate analytical equipment, and there are several practical challenges to overcome before PEMS can be fully implemented. These challenges include the currently limited availability of PEMS equipment and knowledge, constraints on performing emissions tests due to the geographical locations of test sites, traffic conditions, and seasonal climate variations, as well as open safety concerns. Although the EU seems set to forge ahead with its plans for emission regulations in 2020 and beyond, it is the implementation of the test procedures to achieve these targets which continues to be shrouded in uncertainty throughout the industry. Inadequate test procedures Image Source: Transport and Environment The chart above is taken from the Transport and Environment publication – Mind the Gap. The International Council on Clean Transportation (ICCT), (Mock et al, 2012) examined the gap between real-world and test data from 2001 to 2010 model years, based on information from the Spritmonitor database. Spritmonitor is a German website that enables users to record their mileage and amount of fuel purchased, to provide an on-going record of each vehicle’s fuel economy over time. The database represents around 50% of annual car sales in Germany, and with data collected from approximately 4.5 billion vehicle kilometres, it is considered by Transport and Environment to be highly representative. The graph shows CO2 emissions recorded by test data and by real world driving, as well as the growth in disparity between the two, over the period 2001-2011. If taken literally this data suggests that the gap between test emissions and actual emissions has grown by 1% per year since 2002, and if the trend continues an average vehicle in 2020 that emits 95g/km of CO2 in a test environment, will actually emit 124g/km when on the road. This makes for sobering reading for regulators and manufacturers alike; and in further reports the Transport and Environment organisation has highlighted the inadequacy of current test procedures, and the potential for manufacturers to manipulate testing or to take advantage of loopholes to produce artificial results. Manipulation of testing Carmakers are in a competitive business and in todays’ market better fuel economy and lower emissions have become important selling points. Although Transport and Environment are clear that no manufacturers are breaking rules, they have highlighted several ways in which vehicles can be prepared for testing to achieve better results. According to the organisation, such ‘tricks’ include disconnecting the alternator so that no energy is used to recharge the battery during testing, the use of special lubricants (not used in production cars) to reduce friction, and turning off electrical features such as the radio and air conditioning. Other techniques cited include taping over cracks around doors and grills to reduce air resistance, over-inflating tyres, and minimising the weight of the vehicle under test. As long as car makers remain within the test parameters, they are complying with regulations and providing data as required. However, when there is such a potential disparity between test data and real-world data, it becomes ever more apparent that the current procedures are out-dated and in desperate need of updating. Update on European regulations In 2014 the European Parliament voted to pass legislation which applies the stringent target of 95g/km of carbon emissions for 2020, and also supports the implementation of the World-Harmonized Light-Duty Vehicle Test Procedure (WLTP) by 2017. Although the regulation will come into force in 2020, there will be a one-year phase-in period to give manufacturers time to adjust. There will also be an opportunity for OEM’s to earn ‘super credits’ whereby the performance of cleaner models can be used to offset the emissions of lesser performing models. Summary Although these recent developments are a step in the right direction, there still remains a level of uncertainty around the technical implementation of new test procedures. This makes it difficult for manufacturers to prepare for a regulation which may come into force as early as 2017, while there is still a lack of confirmation of exactly what the procedures will entail. Despite the recent reports that test data does not accurately reflect on-road emissions, the EU has confirmed it remains on course to apply emission targets of 95g/km for 2020. The growing difference between test data and real-world figures only serves to highlight the importance of the development of new test procedures. If emission targets are to be achieved on-road as well as in the lab, it is essential not only that new protocols are established, but also that manufacturers are given the tools and information they require to plan and prepare for the changes to test procedures in the coming years. Sources: http://www.transportenvironment.org/sites/te/files/publications/Real%20World%20Fuel%20Consumption%20v15_final.pdf http://www.transportenvironment.org/sites/te/files/publications/2013_09_TE_cars_CO2_report_web_final.pdf http://www.theicct.org/sites/default/files/publications/ICCT_PolicyUpdate_WLTP_Nov2013.pdf http://transportpolicy.net/index.php?title=International:_Light-duty:_WLTP

Real Driving Emissions and Test Procedures

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