Over-emitting Euro 6 vehicles jeapardising success of CAZs

A report from the DVSA has confirmed that some Euro 6 vehicles emit higher quantities of NOx emissions on the road than on their WLTP test.

Tests carried out by the DVSA on a range of popular Euro 6 vehicles identified low and high emitters in line with the results of similar tests conducted for Allow Independent Road-testing (AIR) and published in the AIR Index. The DVSA tests reveal that some fully homologated vehicles meeting the legislated laboratory tests produce up to 20 times the NOx emissions limit during the WLTP track test.

This means city policy makers will be unable to stop over-emitting cars adding to poor urban air quality.

AIR is not aware of a single Clean Air Zone (CAZ) or ULEZ operating in Europe which has implemented a way to discriminate between clean and over-emitting Euro 6 vehicles.

The DVSA’s tests show that during WLTP track tests the Nissan Qashqai diesel was found to be more than 17 times the legislative limit for NOx and the Renault Kadjar diesel was 13 times the same limit. Diesel versions of models within the ranges of the BMW 1-series, Hyundai Tucson, Jaguar F-Pace, Vauxhall Astra and Volvo XC60 were all found by DVSA to be multiple times higher than emission limits for the legislated test cycle. The only car tested by DVSA and found to be within the limits was the Mercedes E-class diesel.

The DVSA document says that "Where there are more significant test failures which are a cause for concern, a number of actions may be appropriate,including further testing and analysis, the manufacturer applying a technical fix or initiating a recall of affected vehicles."

Nick Molden, Co-Founder of the AIR Index said,"Cities who in good faith are using or plan to use Euro 6 as the threshold for access policies will not deliver the air quality improvements expected and will not solve their breach of urban air quality in the time required. The DVSA’s latest test results confirm the importance of independent testing to provide confidence and transparency about actual emissions during on-road driving. We welcome the government’s publication of this report which aligns with the results of vehicles rated for the AIR Index, and it highlights again that not all Euro 6 cars control NOx emissions to the same degree."

Massimo Fedeli, Operations Director and Co-Founder of the AIR Index said: "Car owners, policy makers and citizens in towns and cities where air quality is breaching European limits will be disappointed by both the poor results of these tests and the reaction of those car makers who refuse to take action to remedy the over-emission of NOx from these vehicles. AIR’s mission is to help reduce the negative impacts of vehicle emissions in the short and long term. We believe that only the cleanest internal combustion engine (ICE) vehicles should have free access to cities and the most effective way to determine this is through independent emissions testing. The AIR Index ratings offer cities a legal framework to improve air quality, quickly and effectively, avoiding the potential scenario of vehicle bans which would restrict mobility and penalise clean vehicles."

The latest findings from the DVSA’s ‘2018 Vehicle Emissions Testing Programme’ can be found here.