Quantification of the effect of WLTP introduction on passenger cars CO2 emissions

摘要

In 2014 the United Nations Economic Commission for Europe (UNECE)adopted the global technical regulation No.15 concerning the Worldwideharmonized Light duty Test Procedure (WTLP) while the European Commissionis now aiming at introducing the new test procedure in the European type-approvallegislation in order to replace the New European Driving Cycle (NEDC) as thecertification test. The current paper aims to assess the effect of WLTP introductionon the reported CO2 emissions from passenger cars presently measured under theNEDC and the corresponding test protocol. The most important differencesbetween the two testing procedures, apart from the kinematic characteristics of therespective driving cycles, is the determination of the vehicle inertia and drivingresistance, the gear shifting sequence, the soak and test temperature and the posttestcharge balance correction applied to WLTP. In order to quantify and analyzethe effect of these differences in the end value of CO2 emissions, WLTP andNEDC CO2 emission measurements were performed on 20 vehicles. WLTP CO2values range from 125.5 to 217.9 g/km, NEDC values range from 105.4 to 213.2g/km and the ?CO2 between WLTP and NEDC ranges from 4.7 to 29.2 g/km forthe given vehicle sample.