Are China 6a and China 6b Different?
2 Answers
China 6a and China 6b are different. The specific differences are as follows: Different Standards: China 6a and China 6b have different requirements for the content of carbon monoxide, non-methane hydrocarbons, nitrogen oxides, and PM fine particles in vehicle emissions. Compared to China 6a, China 6b imposes stricter emission requirements for carbon monoxide, non-methane hydrocarbons, nitrogen oxides, and PM fine particles. The data shows that the requirements are significantly stricter, making China 6a essentially a transitional phase to China 6b. Different Implementation Times: China 6a became mandatory for light-duty vehicles starting from July 1, 2020, while China 6b will be mandatory from July 1, 2023. Here is some relevant information: The China 6 standard, also known as the National Sixth Stage Emission Standard for Motor Vehicles, includes "Limits and Measurement Methods for Emissions from Light-Duty Vehicles (China 6)" and "Limits and Measurement Methods for Emissions from Heavy-Duty Diesel Vehicles (China 6)." The implementation of the China 6 standard will impose stricter requirements on emissions such as carbon monoxide, nitrogen oxides, and hydrocarbons.
As someone who usually pays attention to car usage, I can tell you that China 6a and China 6b do have differences. Simply put, China 6b is an upgraded version with much stricter emission standards. China 6a has relatively lenient limits, allowing higher carbon monoxide emissions, which eased the pressure on manufacturers during the transition period. However, China 6b significantly lowers the limits for various pollutants, such as nitrogen oxides and particulate matter, and adds real driving emissions (RDE) tests to detect exhaust emissions, preventing manufacturers from cheating. This means China 6b-compliant vehicles are better for air quality, but they may have more complex systems and slightly higher maintenance costs for owners. If you're buying a car, I recommend choosing a China 6b model—though sometimes more expensive, it’s more environmentally friendly and reliable in the long run, as most new cars now comply with China 6b. Driving a China 6b car feels no different in daily use, with normal power and fuel consumption, but China 6a vehicles may face future driving restrictions due to policy changes. Overall, from a user’s perspective, the difference is quite noticeable and affects decision-making.
