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The ruling last December was spectacular: the EU’s lower court decided that the European Commission had no right to adopt laxer pollution limits for on-road tests of Euro 6 cars. The Commission’s 2016 ‘conformity factor’ decision may sound like a technical detail, but in reality it has meant that carmakers can exceed the legal diesel limit for poisonous NOx of 80mg per km.
The Commission argued in 2016 that such flexibilities were needed to take account of statistical and technical uncertainties when switching from emission measurements in laboratory to ‘Portable Emissions Measurement Systems’ (PEMS) for on-road ‘Real Driving Emissions’ (RDE) tests. But what should have been a very limited flexibility reflecting genuine measurement uncertainties was turned into a ‘license to pollute’ after pressure from EU governments.
Commission reluctant to go beyond current rules
Although the Commission's own Joint Research Center (JRC) suggested the uncertainty of PEMS devices to be as low as a factor of 1.2 back in 2016, governments bowed to lobbying by carmakers and decided to apply a political ‘conformity factor’ of up to 2.1 until the end of 2020 (168 mg/km instead of 80 mg/km), effectively raising the Euro 6 limits. By January 2021, this value is supposed to be reduced to 114 mg/km (a technical ‘conformity factor’ of 1.43). The ruling by the European court presents a golden opportunity to rectify this erroneous decision and deliver a quick win for air quality in Europe.
Yet, the European Commission said it would not seize this opportunity. Instead, it has appealed the court decision and announced that in parallel it would simply propose the same NOx limits under a different legislative procedure. This followed lobbying by carmakers who were quick to cry wolf. They threatened that they may not be able to sell 7.5 million diesel vehicles planned for production if the ‘conformity factor’ is removed as these vehicles are not clean enough to meet the Euro 6 diesel NOx limit.
87% of cars already meet the 80mg NOx limit even in new tests
T&E has analysed data published by manufacturers themselves in order to assess whether Euro 6 NOx limits can already be achieved on the road. RDE data available on the European and Japanese automobile manufacturers associations’ websites shows that a significant amount of diesel vehicles on sale today are already capable of performing well below 80mg of NOx per km. The analysis of 307 RDE results from Euro 6d-temp and 6d diesel vehicles shows that 87% of the tested vehicles were below 80 mg per km of NOx, both under urban driving conditions and during the total trip.
Therefore, in our eyes, there can be no doubt that the technology necessary to meet the 80mg of NOx per km already exists. In the industry’s RDE databases, 59 of the tested vehicles produced less than 20mg of NOx per km during both the urban and the whole of the RDE test. This means there is a considerable margin to meet the 80 mg limit under all possible conditions. As the ongoing EU cartel investigations indicate, several companies may even have been colluding for years in order to shut down competition on cleaner technology and delay the introduction of effective ‘selective catalytic reduction (SCR) systems’.
Some carmakers go for cheapest instead of cleanest technology
If some carmakers find it hard to meet legal limits in on-road tests, this is probably because they have been optimising their emissions control systems to lower costs rather than to provide good on-road emissions performance. Eight RDE tests exceeded the 80mg per km NOx limit across the whole test, which jumps to 37 RDE tests when the results from the urban section are taken into account. This is especially worrying as urban NOx emissions have a huge impact on air quality in cities. Also the RDE regulation states that NOx emissions cannot exceed the legal limit during the urban section as well as the total trip.
The results are even more striking when RDE results are considered by manufacturer. Among the vehicles for which data is available, Volvo exceeded 80mg of NOx per km on 11 RDE tests during the urban part of the drive, Hyundai-Kia 9 and Ford 6.
Carmakers should be required to meet the limit within the uncertainties of the test
The review of the ‘conformity factors’ is a golden opportunity to put an end to that situation and make sure all diesel cars respect Euro 6 limits on the road, too. Limit values are meant to be respected ‘under normal conditions of use’, as the law defined it in 2008. The new law should require carmakers to demonstrate that they meet the limit within the uncertainties of the test. EU lawmakers should ensure there are no more political deals to raise emissions by the backdoor, and pave the way for truly clean – ie, zero-emission – vehicles in parallel.