Worldwide Harmonized Vehicle Test Procedure

The Worldwide Harmonised Light vehicles Test Procedure (WLTP) has been created to define a brand new global harmonised standard for determining levels of pollutants and emissions, fuel consumption, and electrical range in light-duty vehicles.

WLTP will replace the previous fuel economy testing, known as the New European Driving Cycle (NEDC), which was introduced back in 1992.  Since September 2017, all new models introduced to the market for the first time have been tested to WLTP.  All cars sold from September 2018 will be tested to WLTP.  This new laboratory testing will also be supplemented by an emissions test that measures pollutants directly on the road to produce Real Driving Emissions (RDE).

The new WLTP test procedures will enable consumers to have more accurate fuel consumption and CO2 emissions of their vehicles.


Changes to standardised testing procedures

Measurement of emissions in order
to plan adjustments
to passenger cars
Increase in the distance travelled during cycles Tests performed at higher speeds Livelier, more realistic driving behaviour Increase in cycle lengths


One of the aims of the new WLTP test is to better represent everyday driving conditions and vehicles’ current technologies during the accreditation process. It specifies stricter testing conditions and a more dynamic driving profile than the previous NEDC, which was developed in the 1990s. WLTP is based on actual driving data while the NEDC was based on theoretical driving profiles.

WLTP also produces more accurate values because it takes account of the specifications of each car including all of its optional equipment, which can have a significant influence on fuel consumption and CO2 emissions. The WLTP values are, in some cases, higher than the NEDC values for the same vehicle. This does not mean that its fuel consumption performance is worse; it is simply a new measurement based on a more robust and longer test cycle which therefore better reflects how vehicles are currently driven.



Test cycle Single test cycle Dynamic cycle more representative of real driving
Cycle time 20 minutes 30 minutes
Cycle distance 11 kilometre 23,25 kilometre
Driving phases 2 phases, 66% urban and 34% non-urban driving 4 more dynamic phases, 52% urban and 48% non-urban
Average speed 34 kilometre per hour 46.5 kilometre per hour
Maximum speed 120 kilometre per hour 131 kilometre per hour
Influence of optional equipment Impact on CO2 and fuel performance not considered under NEDC Additional features (which can differ per car) are taken into account
Gear shifts Vehicles have fixed gear shift points Different gear shift points for each vehicle
Test temperatures Measurements at 20-30°C Measurements at 23°C, CO2 values corrected to 14°C



From September 2018, as well as the WLTP accreditation protocol, all manufacturers will have to measure their models’ emissions in real driving situations (RDE); this applies to all cars sold in the EU, Switzerland, Turkey, Norway, Liechtenstein, Israel and Ireland.

In these RDE tests, emissions of pollutants such as oxides of nitrogen (NOx) and fine particles are measured on the open road for a more realistic picture.


  • What does WLTP stand for?
  • What is a WLTP driving cycle?
  • What does WLTP mean for me?
  • What does RDE stand for?
  • What does EURO 6 mean?
  • What is selective catalytic reduction?

  • What is an accreditation procedure?
  • Why change the accreditation procedure?
  • Will my fuel consumption rise?
  • What are the implementation deadlines?

WLTP stands for Worldwide Harmonised Light Vehicles Test Procedure.

It is a new testing procedure that provides a more realistic analysis of a vehicle's fuel consumption and CO2 emissions. From September 2018, all vehicles registered for the first time will have to be WLTP-certified. The WLTP will gradually replace the old NEDC (New European Driving Cycle) procedure.

A vehicle’s consumption and emissions still depend on each person's driving style, which is why a large amount of data collected around the world was compiled for the WLTP standard. These data were used to determine four representative phases with four average speeds: low, medium, high and extra high.

During each phase, different situations are measured (braking, acceleration, stopping) in different ways to reflect everyday driving situations. These phases are combined to produce what is called the “driving cycle”.

Fuel consumption is presented for four different driving situations, with a combined overall value for petrol, diesel, hybrid and rechargeable hybrid vehicles.

The entry into force of WLTP means that the fuel consumption and CO2 emissions values indicated in a vehicle description will reflect more accurately the values emitted in real driving situations.

The WLTP test factors in individual options (e.g. winter tyres or glass roof) to calculate more realistic values based on your vehicle's exact configuration.

More realistic values naturally mean that consumption and emissions values will be higher for vehicles equipped with a combustion engine, while electric vehicles (including rechargeable hybrids) will have a lower range. This might also result in more vehicles being liable for the CO2 tax. However, WLTP-accredited vehicles will still be taxed on the basis of the NEDC. In the short term, CO2 emissions-based taxation systems will not change (CO2 tax, tax on company cars).

RDE stands for Real Driving Emissions. It is a new procedure used to measure emissions of pollutants such as oxides of nitrogen (NOx) and fine particles.

As the name suggests, RDE are measured on the open road in real driving conditions, and not in a laboratory. These measurements are obtained using a smart device called PEMS (Portable Emissions Measurement System) attached to the back of the vehicle during the test.

Euro 6 is the current standard that places limits on pollutant emissions. It sets maximum values for emissions of fine particles and oxides of nitrogen which are lower than the previous Euro 5 standard.

From September 2018*, a second version of the Euro 6 standard will come into force: the Euro 6.2 standard. It places even lower limits on particle emissions than the previous standard for vehicles with petrol engines.

*Applies to new vehicles. New types of vehicle will be subject to the new emissions standards one year earlier.

In order to reduce a vehicle’s pollutant emissions still further, liquid ammonia, called AdBlue®, is injected into the exhaust systems of diesel vehicles. Selective Catalytic Reduction (SCR) with AdBlue® can cut oxides of nitrogen emissions by up to 90%, leaving mainly steam, nitrogen and carbon dioxide. 

It is a set of standardised parameters, including the testing cycle, which are used to certify vehicles.
A single accreditation procedure can compare the fuel consumption and CO2 emissions performances of different vehicles.
The NEDC (New European Driving Cycle) had been in force since 1992, and will be replaced by WLTP from September 2018.

The old NEDC procedure was regarded as unrepresentative of our customers’ real driving behaviour.
The consumption figures used in communications, measured using WLTP, will be closer to the levels our customers actually observe.

There will be no impact on your car's consumption as a result of these new WLTP values. WLTP will result in a higher CO2/g/km value than the same vehicle’s NEDC value simply because it is a longer, more rigorous test. As a result, WLTP better reflects real-life driving. In other words, the higher CO2 value does not mean an increase in fuel consumption, but rather a more realistic CO2 value because of the change in the way vehicles are tested.

The WLTP values must be displayed to customers from:

  • 1 January 2019 for passenger cars
  • 1 January 2020 for commercial vehicles.