Ensuring that it remains difficult to pick the saints from the sinners, the latest additions to the comprehensive EQUA Air Quality (Aq) Index show that Euro 6 vehicles continue to deliver drastically different results when tested in the real world.
In an article dated January 15 2017 by Jonathan Leake, Environment Editor at The Sunday Times, Emissions Analytics’ CEO and founder Nick Molden is quoted as saying: “When a vehicle passes laboratory tests but shows such a different performance on the road you have to be suspicious about the technology.”
This comment was made in response to the news that Fiat Chrysler are being investigated by the US’s Environment Protection Agency and the UK’s Department for Transport due to significantly higher real-world NOx emissions than those emitted during laboratory testing.
The EPA has issued a ‘notice of violation’ to Fiat Chrysler – listing alleged devices including timers which are said to switch off parts of the emission control system after the engine has run for the short time needed to conduct tests -for failure to disclose auxiliary emission-control devices, or AECDs, which is a violation of the Clean Air Act.
Emissions Analytics found that Fiat’s 500X MultiJet with a 1.6-litre diesel engine, emitted 14 times above EU and UK limits. The Fiat Doblo van was even worse, with emission 17.8 times above the legal limit, even though it has passed official tests.
For more data on Fiat, and other vehicles visit the EQUA Index.
A visualisation of cars tested for the EQUA Aq Index, split by Euro standard and fuel type, showing progress towards reduction of NOx emissions.
Will 2015 be recognised as a turning point in the campaign for clean air? It certainly has the potential to as there are a number of threads which, if they come together, could determine the future prospects for urban air quality in Europe.
For instance, the second stage of the Euro 6 regulations for passenger cars will come into force from September. All new cars registered will need to meet reduced limits for NOx, albeit still measured on the artificial laboratory New European Driving Cycle (NEDC).
Also, negotiations will come to a head in the EU around the Conformity Factor for the third stage of the Euro 6 regulations. This will see the use of Portable Emissions Measurement Systems (PEMS) becoming mandatory for the first time. Emissions Analytics has argued long for such portable testing in real-world driving, so this is significant progress. However, a high Conformity Factor (the permissible exceedence of the regulated limits) for a long period could limit the effectiveness of the regulation.
Additionally, the UK government must come up with a new air quality plan after its defeat in the Supreme Court. The activist legal group, ClientEarth, accused the government of failing to meet legal limits for air pollution and the Supreme Court found in its favour, instructing the government to draw up a new plan by the end of 2015.
So, let’s take stock of what Emissions Analytics’ real-world test data is telling us on these points.
The second stage of the Euro 6 regulations is likely to reinforce the existing trend of significantly reducing NOx, but there will still be large exceedances over the regulations. Emissions from Euro 6 diesels are on average 0.340 g/km when they should be 0.08g/km, although this is a 54% reduction on the 0.736 g/km from Euro 5. The issue is much less for gasoline vehicles, which are on average 24% below the 0.06g/km limits. However, 22% of vehicles tested by Emissions Analytics did not meet the limit.
Regarding the Conformity Factor at the third stage of Euro 6, there is growing evidence that, in time, a low factor is viable. Across all Euro 5 diesels we tested, just one met the regulated level. So far for Euro 6 four have already met the limit, using a mix of selective catalytic reduction (SCR) and lean NOx trap (LNT) after-treatment systems. There is still much work to do, but the evidence shows that the limits themselves could be met.
A new version of the UK’s air quality plan is being written by the Department for Environment, Food and Rural Affairs and Secretary of State Liz Truss has announced consultation “later this year”. Crucial in our view will be the understanding and modelling of primary NO2 emissions, as this is a major contributor towards roadside pollution yet is not specifically regulated by Euro 6. Emissions Analytics has found that the variation in this fraction of NO2 in NOx between models has also grown, as a result of differences in after-treatment technologies; for Euro 6 diesels it is 17%-80%, where previously is was 27%-70% in Euro 5 models.
To assist the industry in making a success of Euro 6, Emissions Analytics recently launched an online database of its results, which will be updated in real-time as it continues its rolling test programme. We don’t know yet how these important developments will impact urban air quality but we will be tracking it closely.