The European Commission (EC) will appeal an European Court of Justice (ECJ) ruling, which said allowing vehicles to emit more than double the emission limit for NOx – the so-called conformity factor – was illegal.

At the same time as appealing the decision, the EC says it will also prepare new legislation that will have the same effect as the law declared illegal by the courts in December.

Elzbieta Bienkowska, European Commissioner for industry, told MEPs yesterday (Wednesday, February 20) that if the new legislation is adopted in time, the commission would withdraw the appeal.

The legality of the vehicle emissions testing regime was thrown into doubt after the courts ruled the Commission had no power to weaken emissions limits for on-the-road tests.

The new Worldwide harmonised Light vehicle Testing Procedure (WLTP) is supported by a second procedure that measures NOx and particulate emissions, called the Real Driving Emissions (RDE) test.

RDE is a 90-minute on-road test, with apparatus attached to the car measuring exhaust gases. However, the European Commission had introduced a rule allowing vehicles to emit more than double the emission limit for NOx – the conformity factor.

If NOx emission levels exceed 2.1 times those achieved in the WLTP (for example 168mg/km instead of 80mg/km – the current Euro 6 diesel limit), it counts as a fail and the vehicle must be retested before approval.

The conformity factor tightens to 1.8x by 2019 and 1.5x in 2020 (120mg/km instead of 80mg/km) for new cars (and all cars in 2021). It will be reduced to 1x as soon as possible, but by 2023 at the latest.

Three cities – Brussels, Madrid and Paris – challenged the provision amending the emission limits within the RDE test and the ECJ ruled in their favour (fleetnews.co.uk, December 14, 2018).

ClientEarth lawyer Ugo Taddei said the Commission’s decision to appeal the ruling was a “mistake that will delay urgent action to protect the health of all Europeans”.

“The appeal will mean the conformity factors remain in force for a long time, despite the Court ruling them to be illegal,” he continued. “The decision to appeal also sends a negative message to the public.

“We are three years into the dieselgate scandal and the evidence keeps building on the central role car manufacturers are playing in creating the air pollution crisis that is choking our cities. However, the Commission continues to listen more closely to the car industry than to the hundreds of thousands of citizens that want to breathe clean air."

Bienkowska said that she would send the EU parliament and national governments the new legislative proposal soon.