What is WLTP (worldwide harmonised light vehicle test procedure)?
WLTP (worldwide harmonised light vehicle test procedure) is a testing standard used to measure fuel economy and emissions. WLTP began its introduction in 2018, replacing the older NEDC testing standard, and is intended to be a more accurate measure of real-world efficiency. This is why advertised mpg figures for comparable cars got worse after 2018, because they were being measured according to this newer, stricter standard.
Related glossary terms
CAZ - clean air zoneA clean-air zone (CAZ) is a mandate that has come into effect in some UK cities charging drivers of older more polluting cars a fee to enter city centres.ULEZ - ultra low emissions zoneULEZ (ultra-low emissions zone) is an area that includes most of Greater London, which sees a daily charge applied to older petrol and diesel cars driving within the zone.NEDC - new European driving cycleNEDC (new European driving cycle) is an older testing standard used to measure a car's fuel economy (mpg) and emissions.