measuring pollutant emissions, which are more representative of real-world driving conditions Since 1 September 2017, under EU regulations (EU 2017/1151), to obtain vehicle approval two new measurement protocols must be applied (new step in the Euro 6 regulations): pp the WLTP (Worldwide harmonized Light vehicles Test Procedure), which is conducted in a laboratory (cf. § 2.1.1.3.); pp the RDE (Real Driving Emissions) procedure, conducted on the road in “real-life driving conditions”, measures pollutant emissions using a PEMS (Portable Emissions Measurement System) and calculates the admissible conformity factor (the permitted discrepancy between the real-life values in-use and the statutory WLTP thresholds).