WLTP uses new Worldwide harmonised Light-duty vehicle Test Cycles (WLTC) to measure fuel consumption, CO2 and pollutant emissions from passenger cars and light commercial vehicles. The new protocol aims to provide customers with more realistic data, better reflecting the daily use of the vehicle.
The new WLTP procedure is characterized by a more dynamic driving profile with more significant acceleration. The maximum speed increases from 120 to 131.3 km/h, the average speed is 46.5 km/h and the total cycle time is 30 minutes, 10 minutes more than the previous NEDC. The distance travelled doubles from 11 to 23.25 kilometers. The WLTP test consists of four parts depending on the maximum speed: Low (up to 56.5 km/h), Medium (up to 76.6 km/h), High (up to 97.4 km/h), Extra-high (up to 131.3 km/h). These parts of the cycle simulate urban and suburban driving and driving on extra-urban roads and motorways. The procedure also takes into account all vehicles’ optional contents that affect aerodynamics, rolling resistance and vehicle mass, resulting in a CO2 value that reflects the characteristics of the single vehicle.
The new WLTP test procedure is more representative of current driving conditions than the NEDC procedure, but it cannot take into account all possible cases including the effect of the driving style that is specific to each individual driver.
Therefore, there will still be a difference between emissions and consumption measured in the laboratory and those resulting from the use of the vehicle in the real world, and the extent of this difference will depend on factors such as driving behavior, the use of on-board systems (e. g. air conditioning), traffic and weather conditions that are characteristic of each geographical area and each driver.
For this reason, only a standardized laboratory test allows to obtain values with which it is possible to compare vehicles and different models in a fair way.
The new WLTP procedure will provide a more realistic criterion for comparing the fuel consumption and CO2 emission values of different vehicle models as it has been designed to better reflect real driving behavior and take into account the specific technical characteristics of the individual model and version, including optional equipment.
To ensure clarity and maximum possible transparency, FCA will provide retailers and customers with detailed information on the fuel consumption and CO2 emission values of each configured car and on the minimum and maximum extremes of the various models.