WLTP: How the second stage works 🎥
BACKGROUND Euro 6d TEMP EVAP ISC is the name of the emissions standard that will become mandatory with the second stage of type testing under the Worldwide harmonized Light vehicles Test Procedure (WLTP) from September 1, 2019. In the process, the WLTP procedure introduced last year will be tightened again by new requirements and the technical effort involved in type testing will be increased once again. [...]
The WLTP procedure introduced last year will be made more stringent by new requirements and the technical effort required for type approval will be increased once again. The abbreviation "EVAP" (Evaporative Emissions) stands for the verification of evaporative emissions.
Exams go new over 48 hours
An activated carbon filter in the tank system already prevents gasoline vapors from being released into the environment, for example in Volkswagen models. Until now, this has been tested in an airtight chamber over 24 hours. In the future, the period will be 48 hours - with the same limit values. To meet these additional requirements, the vehicles will be technically modified.
Measurements of the vehicle in operation
A significant change in the second WLTP stage is the measurement of whether the emission limits are still met when the vehicle is in operation. To this end, vehicles up to five years old will in future be subjected to a WLTP test on a random basis. This field monitoring (ISC = In Service Conformity) will be carried out on selected vehicles with a mileage of up to 100,000 kilometers.
Current procedure provides legal certainty
The first WLTP stage came into force for all new vehicles on September 1, 2018. The fact that the next stage will follow just one year later and that there will be others is due to the high complexity of the procedure. The regulations that will come into force from September 2019 also contain concretizations of the previous procedure and provide legal certainty.
