For some years, the European Commission have been concerned that the currently specified emissions test procedures and drive cycles for light duty vehicles (known as the New European Drive Cycle or NEDC) do not accurately reflect real world driving and, as a result, the reductions in pollutant emissions limits and the targets on fuel consumption and CO2 emissions that have been introduced in recent years have not translated into equivalent improvements in the real world. For this reason, the European Union were a major contributor into the development of the worldwide harmonised light duty vehicle test procedure (WLTP), which was first published as Global Technical Regulation (GTR) No. 15 in 2014, and the European Commission have a long standing commitment to replace the NEDC with the WLTP in the EU light duty vehicle emissions requirements at the earliest possible opportunity.
Currently, in EU legislation, the main emissions requirements applicable to light duty vehicles (i.e. the emissions limits and introduction dates) are specified in EC Regulation No. 715/2007 and the detailed requirements (i.e. test procedures, measurement procedures, etc.) are specified in an Implementing Regulation; EC Regulation No. 692/2008. To introduce the WLTP into the EU emissions requirements, the European Commission have chosen to create a completely new Implementing Regulation that will replace EC Regulation No. 692/2008. This meant creating a new draft Regulation containing all of the detailed requirements and test procedures required for the implementation of the emissions requirements specified by EC Regulation No. 715/2007, including those on idle CO testing, access to repair and maintenance information, engine power testing, etc., although many of them could be carried over from EC Regulation No. 692/2008 unchanged.
The first official draft version of this proposed new Implementing Regulation was made available for discussion at the Technical Committee - Motor Vehicles (TCMV) meeting which took place in Brussels on 15th March, 2016. Within this draft Implementing Regulation, an Annex has been allocated (Annex IIIA) to contain the new requirements on real driving emissions (RDE), once they are finalised and agreed, and the WLTP requirements have been placed in Annex XXI.
Work on the further development and refinement of the WLTP has continued under the auspices of the United Nations Economic Commission for Europe (UN ECE) in parallel to the drafting of the new EU Implementing Regulation and the WLTP requirements contained in the draft Implementing Regulation are based on the latest version of the WLTP, known as Phase 1b, which was only adopted by the UN ECE Working Party on Pollution and Energy (GRPE) at their January 2016 meeting.
Due to the sheer size and complexity of the draft Implementing Regulation, it is not possible to summarise all of its requirements within this article. However, there are three points that are particularly worthy of note.
Pollutant Emissions Limits
Although this draft Implementing Regulation introduces new test procedures and drive cycles for emissions testing, the pollutant emissions limits that the vehicle must comply with remain as specified in EC Regulation No. 715/2007, i.e. Euro 6.
Ambient Temperature Correction
The WLTP requirements specify that the test vehicle must be "soaked" at an ambient temperature of 23°C prior to the emissions test and that the ambient temperature in the test cell during the emissions test must be maintained at 23°C. However, to be representative of the ambient temperatures across the European Union, the European Commission have dictated that the official European fuel consumption and CO2 emissions figures should be determined at 14°C.
To achieve this, the draft Implementing Regulation requires a representative vehicle to be tested at both 23°C and at 14°C and the results from both of these tests to be compared to determine an ambient temperature correction factor. This factor is then applied to the fuel consumption and CO2 emissions figures determined at 23°C to establish the official European fuel consumption and CO2 emissions figures.
NEDC Equivalent CO2 Emissions
Due to the fact that the existing EU Regulations specifying targets on the CO2 emissions performance of new passenger cars and new light commercial vehicles, (EC) No. 443/2009 and (EU) No. 510/2011 respectively, are based on CO2 emissions figures measured using the NEDC drive cycle and that many Member States have taxation systems in place based on NEDC based CO2 figures, it will be necessary to determine NEDC based CO2 emissions figures for some time after the WLTP has been introduced. Therefore, a specific computer simulation programme called Co2mpas has been developed to calculate NEDC based CO2 emissions figures based on the CO2 emissions results from WLTP testing and the use of this simulation programme is required by the draft Implementing Regulation.
With regard to introduction dates, the draft Implementing Regulation specifies the following:
| New type approvals | All new vehicles | |
|---|---|---|
|
M1 and M2 category vehicles, and N1 category vehicles of Class I (i.e. reference mass ≤ 1305 kg) e.g. passenger cars, multipurpose passenger vehicles, minibuses, car derived vans and small pick-up trucks |
1st September 2017 | 1st September 2018 |
|
N1 category vehicles of classes II and III (i.e. reference mass > 1305 kg) and N2 category vehicles e.g. vans, large pick-up trucks and light trucks |
1st September 2018 | 1st September 2019 |