What is the difference between China 6a and China 6b?
1 Answers
The difference between China 6a and China 6b lies in their implementation timelines. China 6a became mandatory for light-duty vehicles starting from July 1, 2020, while China 6b will be enforced from July 1, 2023. Another key distinction is that China 6a serves as a transitional phase between China 5 and China 6, whereas China 6b represents the formal stage three years after China 6a. China's automotive emission standards are modeled after European emission standards, with the latest being the National Phase 6 emission standard. The Phase 6 standard imposes stricter limits, significantly reducing the permissible levels of various harmful gases. Automotive emission standards regulate the maximum allowable emissions of harmful gases such as carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM) from vehicle exhaust. These standards are established to curb the production of these pollutants, encouraging manufacturers to improve vehicle emission performance and reduce harmful emissions. Most regions in China officially implemented the China 6 standard on July 1, 2019. The deadline for registering China 5 vehicles in various regions corresponds to the local implementation date of the China 6 standard. Some areas have extended grace periods for China 5 vehicle registration; for example, China 5 vehicles purchased before July 1 may be registered until August 1 in certain regions.
