The NEDC and WLTP homologation protocols explained by PEUGEOT | Media Peugeot International

The NEDC and WLTP homologation protocols explained by PEUGEOT

download-pdf
download-image
download-all
Thu, 20/08/2020 - 14:00

These 2 protocols have the same objective: to measure the regulated pollutants (CO/HC/Nox/particles) and the consumption expressed in CO2 over the cycle for a new vehicle, yet one will be replacing the other.
Introduced in 1992, the NEDC protocol (New European Driving Cycle) has become outdated and has been gradually replaced by the WLTP protocol (Worldwide Harmonized Light Vehicles Test Procedure) since September 2017, which is much closer to the real conditions of vehicle use.
The new WLTP test gives consumers a more realistic view of regulated pollutant emissions and CO2 consumption of vehicles with much more representative data.



THE TIMETABLE FOR THE FINAL SWITCHOVER TO WLTP

The WLTP officially replaced the previous NEDC test procedure in September 2017 for passenger cars and in September 2018 for light commercial vehicles (Class II and III).

In order to limit any confusion in the minds of consumers between the NEDC and WLTP values, there is an extended transition phase in place from September 2017 to January 2021. During this period, and depending on the country, the fuel consumption and CO2 values used for energy classifications, commercial brochures, leaflets and websites were either the NEDC values, the WLTP values or both, but always the same for all manufacturers within a country.

WLTP values have been used in Finland since 09/2018, in Portugal since 01/2019, in France since 01/03/2020.

Some European countries will continue to use the NEDC CO2 values until 12/2020 (e.g. Italy, Spain, etc.)

THE WORLD-WIDE HARMONIZED LIGHT VEHICLE TEST PROCEDURE (WLTP)

The World-wide harmonized Light Vehicle Test Procedure (WLTP) measures regulated pollutants (CO/HC/Nox/particles) and consumption expressed as CO2 over this cycle.

This new procedure has established more realistic testing conditions in order to provide more representative information to customers.

The tests are supervised by the Technical Services (UTAC in France) based on standardised driving cycles (time, speed, equipment, temperature, etc.), in the same way for all manufacturers.                              

FROM THE NEDC TEST TO THE NEW WLTP TEST

Today, drivers are increasingly concerned about environmental issues. This is why regulated emissions (CO, HC, Nox, Particles) and consumption expressed in CO2 are a factor that buyers take into consideration before purchasing a vehicle. It was therefore important that the testing conditions be as close as possible to the buyers' actual driving.

To make things clearer, here are the main differences between the two test procedures:

Cycle test

NEDC

WLTP

Cycle time

20 minutes

30 minutes

Cycle distance

11 kilometres

23.25 kilometres

Driving

2 phases: urban driving 66% / extra-urban driving 34%.

4 phases: urban driving 52% / extra-urban driving 48%.

Average speed

34 km/h

46.5 km/h

Maximum speed

120 km/h

131 km/h

Influence of optional equipment

The options and their impact on regulated emissions (CO, HC, Nox, Particles) and consumption expressed in CO2 are not taken into account.

Options and their impact on regulated emissions (CO, HC, Nox, Particles) and consumption expressed in CO2 are taken into account.

Gears (manual gearbox)

Pre-determined and fixed gear shifts

Gear changes determined according to vehicle characteristics

Temperature testing

Measurements taken at temperatures between 20 and 30°C

Measurements taken at 23°C, then at 14°C for CO2 emissions

 

THE PROS OF THE WLTP TEST

The new WLTP test provides consumers with a more realistic overview of vehicle emissions because the testing conditions are based on a closer representation of actual driving conditions.

The WLTP has redefined much more stringent testing conditions coupled with higher speed tests with a significantly longer test time (30 minutes instead of 20).

In order to achieve a more representative view of CO2 emissions, the new homologation protocol includes both the standard equipment and all optional equipment on the vehicle. This leads to fuel consumption and CO2 emission values based on the aerodynamics, weight and rolling resistance of the configured vehicle with all its equipment and options.

In addition, the WLTP has been developed using actual driving data collected from around the world. The WLTP therefore better represents daily driving profiles. It was developed with the aim of being used as a universal test cycle. Therefore, pollutant and CO2 emissions can be comparable worldwide. However, the European Union and other regions will apply the test in different ways depending on their laws and traffic regulations.

NB: It is currently only rolled out in Europe.

WHAT CHANGES FOR THE CONSUMER?

One of the different goals of the WLTP is to enable the consumer to make more realistic comparisons between cars when considering regulated emissions (CO, HC, NOx, Particulate Matter) and CO2 consumption.

The aim of the homologation protocol is to be able to compare all offers on the market according to the same measurement standard. The NEDC already allowed for this. The WLTP protocol mainly provides a more realistic consumption value. The evolution of the homologation protocol therefore provides a single measurement standard for all vehicles in Europe, a standard that is more representative and more realistic of actual use.

Today, each car produced comes with a compliance certificate which includes CO2 values based on the current WLTP test. On the basis of this official document, which could be described as the vehicle's birth certificate, the vehicle can be registered anywhere in Europe.

It is important to remember that neither the performance nor the actual fuel consumption is affected, regardless of the approval protocol. However, the announced values of CO2 emission levels will be more realistic as the new WLTP protocol better reflects the daily use of the vehicle based on the personal configuration of the vehicle. It will be higher for combustion engine vehicles and the stated range value for electric vehicles and PHEVs will be lower than that stated in the NEDC.

The WLTP test gives more realistic results than the NEDC test but does not affect the performance or fuel consumption of vehicles or the range of electric vehicles. Taxes will be adapted to this new measurement protocol.

 

Scroll