Worldwide harmonized Light-duty vehicles Test Procedure (WLTP)
Effect on declared v/s real world fuel consumption
A vehicle’s fuel economy and emission norm compliance is evaluated by various legislative systems across the world by standardized test procedures. The NEDC (New European Driving Cycle) has been in effect since 1992, with the latest update in 1997. It consists of several test modes to evaluate the emission levels and fuel economy of powertrain combinations across the variants produced by the OEMs. In its modern-day limitations, however, the NEDC includes several tolerances and flexibilities which do not account for many recent automotive engineering developments, driving options and laboratory simulation conditions, since it was never principally designed to measure CO2 emissions and fuel consumption. Thus, to provide more precise simulation of realistic driving conditions and consequent derivation of fuel consumption data, the WLTP (Worldwide harmonized Light-duty vehicles Test Procedure) was brought forward to succeed the NEDC on September 1, 2017. The new test procedure was developed on behalf of the United Nations’ (UN’s) “World Forum for Harmonization of Vehicle Regulations” body and entailed minor regional adjustments due to the differing climatic zones of various UN member states.