What does China 5 refer to in automobiles?

[DeRobert]

China 5 refers to the National Fifth Stage Emission Standard for motor vehicle pollutants, which is equivalent to the Euro 5 emission standard currently implemented in Europe. Compared to the China 4 standard, the China 5 standard reduces nitrogen oxide emissions by 25% for light-duty vehicles and 43% for heavy-duty vehicles. After the implementation of the China 5 emission standard, vehicle pollutant emissions will be significantly reduced, and vehicles meeting the China 2 emission standard will be mandatorily scrapped. For environmental protection, China has now promulgated the China 6 emission standard, which is divided into two phases: China 6a and China 6b. Compared to the China 5 standard, the China 6 standard imposes stricter controls on vehicle exhaust emissions.