What is the equivalent of Euro 4 in domestic emission standards?

[ElainaLynn]

Euro 4 emission standard is equivalent to China's National IV standard. Below is the relevant information: 1. National IV: The National IV emission standard is China's fourth-stage motor vehicle pollutant emission standard. The main pollutants emitted by vehicles include HC (hydrocarbons), NOx (nitrogen oxides), CO (carbon monoxide), PM (particulate matter), etc. Through the application of technologies such as improved catalytic converter active layers, secondary air injection, and exhaust gas recirculation systems with cooling devices, the standard controls and reduces vehicle emissions to below specified levels. 2. Euro 4 and National IV: China's vehicle emission standards are based on European standards, but Euro 4 and National IV are not entirely identical. China's National IV emission standard for light-duty vehicles is completely identical to the Euro Ⅳ standard in terms of pollutant emission limits. However, some improvements have been made in the implementation methods, and there are significant differences in the regulatory format compared to the Euro Ⅳ standard.