Starting September 2017, a new test procedure for measuring fuel consumption and CO2 emissions apply.

Background

Car emissions are responsible for about 12% of total CO2 emissions in the European Union. Because CO2 is one of the main greenhouse gases, the EU therefore decided a few years ago to reduce car-traffic-causing CO2 emissions by 2015 to 130 g/km and by 2020 to 95 g/km. The 2020-target implies a reduction of about 40% of CO2 emissions compared to 2007.

Standardised testing procedures are used for calculating vehicle fuel consumption and emissions. The national authorities play a crucial role in this context. Any vehicle placed on the EU market must be previously tested by a national authority using a laboratory-based test cycle. To the present day, this was the New European Driving Cycle (NEDC). If the vehicle type meets the standards under this test, the national authority will issue the type approval. Car manufacturers can apply for type approvals in the EU Member State of their choice. As soon as the vehicle obtains a type approval in one EU Member State, all vehicles of the same type can be registered for sale throughout the EU.

 

Dieselgate

The NEDC was largely developed in the ‘70s and consists of four repeated urban driving cycles and one extra-urban driving cycle:

  • during the urban driving cycles, 1 km is done in 200 seconds (with 3x pull out and stop) at a maximum speed of 15km/h, 32km/h and 50km/h;
  • the extra-urban drive cycle is 7 km and takes 400 seconds (at speeds of 50, 70, 100, and 120 km/h).

The test is based on a theoretical driving model performed in a laboratory environment. The total ride is 11 km and takes about 20 minutes. The CO2 emissions are measured in g/km and converted into fuel consumption in liters per 100 km.

For the purpose of achieving the EU CO2 emission reduction targets, car manufacturers have therefore an interest in placing cars on the market with the lowest possible CO2 emissions. This has in some cases led to type approval manipulation by some car manufacturers. The so-called Dieselgate scandal of 2015 revealed that some car manufacturers used software that is capable of detecting when a vehicle was being tested and, at the time of testing, it would activate a specific engine mode to run the vehicle according to a combustion that did not reflect the reality but did meet the test’s emission standards.

Moreover, there is general consensus that the NEDC test procedure is outdated. The test was largely developed in the ‘70s at a time when CO2 emissions were not high on the political and environmental protection agenda.

The test is also outdated in part due to the many technological developments that have taken place and have had an impact on fuel consumption (such as four-wheel drive, air conditioning, electric windows, etc.) and also due to changing driving conditions (increasing traffic, traffic jams, etc.).

To respond to the challenges outlined above, the EU decided to introduce gradually as from September 2017 a new test procedure, namely the Worldwide Harmonized Light Vehicle Test Procedure (WLTP).

 

WLTP

The primary legislation for the WLTP is EU Regulation 2017/1151 and its implementing regulations, published on July 7, 2017 in the Official Journal of the European Union. The legislation enters into force today on July 27, 2017 and provides for a gradual replacement of the NEDC with the new WLTP test procedure for measuring vehicle fuel consumption and CO2 emissions:

  • starting September 1, 2017, the WLTP test cycle will in principle apply to all new vehicle models placed on the EU market for the very first time;
  • starting September 1, 2018, all new types of cars (so not only models) should be tested using the WLTP;
  • from now until September 2019, there is a transitional arrangement for some end-of-series vehicles that have been tested under the NEDC regime but have not been sold yet.

What is important is that the WLTP is imposed by a European Union Regulation, so it is binding in its entirety and directly applicable in all EU Member States without any additional national implementing measures.

The expectation is that the WLTP will ensure more realistic and reliable data on vehicle fuel consumption and CO2 emissions. The test conditions under the WLTP are indeed more realistic:

  • a higher average and maximum speed must be tested;
  • various driving conditions, urban traffic, extra-urban traffic, more dynamic accelerations and delays, higher engine power, and more realistic driving behavior must be taken into account;
  • the test distance and duration are longer; and
  • the optional equipment of a modern car and its impact on fuel consumption and emissions must be taken into account.

The main changes that the WLTP has brought to the test procedure, compared with the NEDC, are as follows (source: www.wltpfacts.eu):

Although the WLTP test cycle corresponds better to real car traffic (it records about 20% higher consumption figures and CO2 values ​​than the NEDC), it will remain a test in a laboratory environment. Therefore, the WLTP test procedure is complemented by a test taking on real roads under on-road conditions, from which the Real Driving Emission (RDE) is tested. Under the RDE, the vehicle is equipped with a mobile measurement station that analyses the emissions at any time and verifies if the emissions are within the limits of the legal standards. In doing so, the WLTP legislation provides an additional guarantee that the results obtained in the test banks correspond to the actual vehicle fuel consumption and emissions.

 

Impact on the consumer

The WLTP is a good thing for the consumer. The type approvals under the WLTP will correspond more to reality. However, the actual vehicle fuel consumption and emissions depend largely on additional factors too, such as:

  • the driver's personal driving style;
  • the actual traffic conditions (higher traffic means less continuous fuel consumption); and
  • the environmental factors (such as the weather, temperature, geography of the environment).

Every driver must be aware that these factors come into play at all times.

Moreover, as from September 2017, consumers will be exposed to different measurement results obtained from the various test procedures (WLTP, as said, measures about 20% higher than the results under the NEDC). A vehicle tested under the WLTP test cycle can show higher fuel consumption and emission values, but in reality, it might consume and emit less than a vehicle tested under the NEDC cycle. This could cause confusion among consumers and makes comparing vehicles more difficult for them. Consumers should therefore be aware of these differences when comparing the CO2 emissions and consumption values that are advertised.

The WLTP could probably also stimulate new technological developments in the automotive industry. As of September 2018, new models must indeed be tested according to the WLTP cycle, which requires a reduction of about 20% consumption and emissions compared to the current test procedure. It’s an easy misstep towards the creation of a new Dieselgate. Both the national authorities and the car manufacturers (peer review) must therefore ensure that the WLTP does not lead to new abuse in the automotive sector, but rather it benefits mankind and the environment. This is and should be the ultimate goal of the WLTP.