Photo: / Friends of the Earth Scotland CC BY

Diesels in low-emission zones?

More than 90 per cent of Euro 6 diesel cars on sale today don’t meet the EU emission limits on the road but are still exempt from low-emission zones or diesel bans.

Green transport organisation Transport & Environment (T&E) has analysed low-emission zones and congestion charges in eleven EU cities and found large differences in the systems implemented so far. While some policies exclude high-polluting vehicles permanently and are intended to promote cleaner transportation options, others are more short-term responses to hazardous air pollution episodes.

Although the vast majority of new Euro 6 diesel cars don’t meet the EU emission limits for nitrogen oxides (NOx) in real-world driving conditions, they still manage to escape low-emission zones or diesel bans. According to the T&E study, around 90 per cent of the Euro 6 diesel cars still exceed the NOx limit by a factor of 4–5. Some models even have emissions that are up to 10 times higher, notably from carmakers such as Renault, Fiat and Opel (see AN 3/17, pp. 8-9). Moreover, there are Euro 6 diesel cars that emit more NOx on the road than much older Euro 4 and Euro 5 cars that are banned.

Julia Poliscanova, clean vehicles manager at T&E, said: “One of the key weaknesses of the low-emission zones and car restrictions in cities is the blanket exemption of mostly dirty Euro 6 diesels. Unless carmakers properly fix these dirty diesels, cities are left with no other option but keep them out of city centres. To be effective, the inclusion/exclusion criteria of these measures should be based on vehicles’ real-world emissions that are now widely available. More importantly, diesel bans should be accompanied by high-quality public transport and infrastructure for shared and zero-emission vehicles.”

On 27 February, a ruling by Germany’s highest federal administrative court confirmed that German cities can introduce diesel restrictions with immediate effect and clarified that the right of citizens to breathe clean air takes precedence over the right of private car owners to drive polluting vehicles. However, in some other EU countries national legislation is still preventing cities from taking action, and the T&E says that the German court ruling should be a precedent EU-wide.

As more and more cities introduce restrictions for dirty diesel cars, the air pollution problem may shift to Central and Eastern European countries, due to second-hand cars imported from Western Europe.

“The European Commission should consider what measures can be put in place to ensure all second-hand imported cars have had their exhaust treatment systems fixed or upgraded. All Europeans have an equal right to clean air and a joint EU solution is needed,” said Poliscanova.

In order to ensure that low-emission zones and diesel bans are fully effective, T&E recommends:

  • To avoid blanket exemptions of Euro 6 diesels and instead only allow vehicles that are clean in real-world driving, including those that have been fixed.
  • That the vehicles with emissions above the EU limits should either be adequately fixed, at the expense and responsibility of the car manufacturer, or not allowed in city centres. Unaltered performance and fuel consumption should be guaranteed to drivers.
  • The use of remote sensing linked to number plate recognition to police compliance as well as to identify individual grossly polluting models and ensure these are repaired or cannot enter the city.
  • Cities to be given powers to put in place permanent vehicle restriction policies to help them achieve air quality standards.
  • Investments in public transport, incentives to reduce vehicle ownership as well as infrastructure for zero-emission vehicles, shared and active mobility (e.g. cycling lanes) to help secure public acceptance and local buy-in.
  • Consistency between all policy levels (EU, national and local) to help reduce pollution and make cities clean and liveable. At EU level, emission limits should not favour diesel but instead follow the principles of technology and fuel neutrality. At national level, vehicle taxation should include an air quality increment to avoid skewing the market in favour of diesels.

In September last year, a study by the international research institute IIASA concluded that excess emissions from diesel vehicles that exceed certification limits were associated with at least 5,000 premature deaths annually in the EU.

Christer Ågren

T&E press release and report “How to get rid of dirty diesels on city roads”, 14 March 2018. See:

Low emission zones (LEZ) for cars in the European Union. Illustration: T&E



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