The full form of WLTP is Worldwide-Harmonized Light-Duty Vehicles Test Procedure. It’s used on Transport & Travel ,Land Transport in Worldwide

The WLTP procedure (world harmonized light-duty vehicles test procedure) is a global, harmonized standard for determining the levels of pollutants, CO₂ emissions and fuel consumption of traditional and hybrid cars, as well as the range of fully electric vehicles.

This new protocol is Addenda No. 15 to the Global Registry (Global Technical Regulations) defined by the 1998 Agreement adopted by the Inland Transport Committee of the United Nations Economic Commission for Europe (UNECE), agreement accepted by China, Japan and the United States, and approved by the European Union

The Worldwide Harmonised Light Vehicle Test Procedure (WLTP) replaced the NEDC test procedure for establishing the official Fuel Consumption and CO2 emissions of new cars in September 2017, which became mandatory for all new cars (powered by an Internal Combustion Engine) by September 2018.

The new testing regime aims to provide a closer representation of ‘real-world’ fuel consumption and CO2 figures and provide model specific values at the point of sale. It differs from the previous process in a number of ways, although all tests will continue to be conducted in a laboratory allowing meaningful comparisons between cars to be made.   One of the obvious differences is the structure of the data resulting from the new test. For petrol / diesel cars for example, the terms used to describe test cycle driving phases: “urban”, “extra-urban” and “combined”, is no longer be used.

In their place, the data is being expressed as “Low”, “Medium”, “High”, “Extra-high” and “Combined”.   Currently, the New Car Fuel Consumption database (https://carfueldata.vehicle-certification-agency.gov.uk/)  shows WLTP results for Fuel Consumption.

Results shown for CO2 emissions however, will continue to be NEDC or NEDC equivalent figures until 1st April 2020 (see  Statutory Instrument 2018 No. 673 – ROAD TRAFFIC ENVIRONMENTAL PROTECTION The Road Vehicles (Defeat Devices, Fuel Economy and Type- Approval) (Amendment) Regulations 2018).