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rom NEDC to WLTP: Why is this big change in testing standards so important
As the world pays more and more attention to environmental protection and energy conservation and carbon reduction, the testing methods of vehicle emission standards need to be adjusted accordingly. Starting from September 1, 2019, the new global standard - the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) officially replaced the old European New Driving Cycle (NEDC). This change not only affects the registration and sales of vehicles, but also has important implications for environmental protection and economic benefits.
Background and objectives of WLTP
WLTP is a global driving cycle standard designed to more accurately assess the emissions of traditional internal combustion engine vehicles and hybrid vehicles based on actual road conditions, and to verify the full electric driving range of plug-in electric vehicles. This standard has been recognized by many countries including China, Japan, the United States and the European Union, and its final version was released in 2015.
“The main purpose of WLTP is to make laboratory test results closer to fuel consumption and emissions data under actual road conditions.”
Main differences between NEDC and WLTP
NEDC's design was rooted in the 1980s and was more suitable for the driving environment at the time. In the past, NEDC was evaluated at an average speed of 34 km/h and in calm test conditions. However, the way people drive today has changed significantly, making the NEDC outdated. The WLTP is more realistic. The average test speed is increased to 46.5 km/h, and it begins to simulate various driving scenarios including cities and highways.
"The WLTP test structure is more dynamic than the NEDC and can more realistically reflect the current driving environment."
Rigorousness of testing procedures
The WLTP test procedure provides strict guidance on the test environment and test conditions, including the vehicle's gross weight, fuel quality and tire pressure. In WLTP, vehicles are divided into three categories and tested according to their power-to-weight ratio. Such grading standards combined with more complex test cycles make the test results more comparable.
Real driving emissions test
WLTP is not just a laboratory test procedure, it also includes an additional test called Real Driving Emissions (RDE), which checks whether the vehicle's emissions comply with the regulations under real-life conditions. The use of a portable emission measurement system (PEMS) provides more accurate data for this process.
"The introduction of RDE is a powerful supplement to WLTP and is of great significance in solving the air pollution problem."
Summary: Where is the future?
The implementation of WLTP undoubtedly marks a major leap forward in automobile emissions testing. However, as standards change, manufacturers must strike a balance between technological innovation and compliance costs. The world will observe how this change affects the prospects of the global automotive industry and will find an ideal combination between environmental protection and economy. Will this become a benchmark for the future automotive industry?
