New Real Driving Emissions Tests for Diesel Cars

To bring light into this area, the EC haa reformed the way tests should be conducted so they reflect actual emissions in real driving conditions. Now, Member States have agreed that from 1 September 2017 these new real driving emissions (RDE) tests will determine whether a new car model is allowed to be put on the market.

Commissioner Elżbieta Bieńkowska, responsible for Internal Market, Industry, Entrepreneurship and SMEs, said: “The EU is the first and only region in the world to mandate these robust testing methods. And this is not the end of the story. We will complement this important step with a revision of the framework regulation on type-approval and market surveillance of motor vehicles. We are working hard to present a proposal to strengthen the type-approval system and reinforce the independence of vehicle testing. We are listening to the many views expressed and ideas put forward, and I thank the European Parliament in particular for its valuable input.”

The technical regulatory committee gathering Member States representatives agreed that the new RDE test will have a binding impact on the type-approvals issued by the national type-approval authority (TAA) from September 2017 for all newly approved types of vehicles (from September 2019 for all new vehicles).

Given technical limits to improving the real world emission performance of currently produced diesel cars in the short-term, Member States agreed that car manufacturers must reduce the divergence between the regulatory limit that is tested in laboratory conditions and the values of the RDE procedure when the car is driven by a real driver on a real road (the so-called “conformity factor”) in two steps:

• in a first step, car manufacturers will have to bring down the discrepancy to a conformity factor of maximum 2.1 (110%) for new models by September 2017 (for new vehicles by September 2019);
• in a second step, this discrepancy will be brought down to a factor of 1.5 (50%), taking account of technical margins of error, by January 2020 for all new models (by January 2021 for all new vehicles).

The agreement the allowed divergence between the regulatory limit measured in real driving conditions and measured in laboratory conditions is still a significant reduction compared to the current discrepancy (400% on average).

Background

Flickr: Jonathan Cohen

Over the past few years, the Commission has set as a goal to tighten up both the actual NOx emissions limits and the testing procedures. Nitrogen oxide (NOx) emissions limits for diesel vehicles have been reduced as follows (all application dates to new emission type approvals, application to all new vehicles always 1 year later):

• January 2000: 500 mg/km (Euro3)
• January 2005: 250 mg/km (Euro 4)
• September 2009: 180 mg/km (Euro 5)
• September 2014: 80 mg/km (Euro 6)

Now, the introduction of new RDE testing methods is a further tightening of the screws. According to Commission data, currently produced Euro 6 diesel cars exceed the NOx limit 4-5 times (400%) on average in real driving conditions compared to laboratory testing.

The new RDE test procedure was voted in May 2015 by the relevant regulatory committee (Technical Committee of Motor Vehicles – TCMV) and will come into force early 2016. The RDE procedure will complement the laboratory based procedure to check that the emission levels of nitrogen oxides (NOx), and at a later stage also particle numbers (PN), measured during the laboratory test are confirmed in real driving conditions.

This means that the car will be driven outside and on a real road according to random acceleration and deceleration patterns. The pollutant emissions will be measured by portable emission measuring systems (PEMS) that will be attached to the car. RDE testing will significantly reduce the currently observed differences between emissions measured in the laboratory, and those measured on road under real-world conditions, and to a great extent limit the risk of cheating with a defeat device. During the initial phase starting January 2016, the portable RDE testing system will be used for monitoring purposes.

On 28 October 2015, the TCMV voted on the second package of measures on the regulatory not-to-exceed (NTE) emission limits applicable in RDE testing, which needs to enter into force so that RDE testing has implications on the conformity certificate issued by the national type-approval authority (TAA).

Next steps

The draft regulation will now be sent to the European Parliament and the Council for scrutiny.