What do China V and China VI mean?

[StCassidy]

China V refers to the China 5 standard. China VI represents the China 6 standard. Below is relevant information about China 5 and China 6: 1. China 5, the full name is the National Fifth Stage Emission Standard for Motor Vehicle Pollutants; China 6, the full name is the National Sixth Stage Emission Standard for Motor Vehicle Pollutants. Both refer to the emission standards for vehicle exhaust. Vehicle emission standards regulate the content of harmful gases such as CO (carbon monoxide), HC+NOx (hydrocarbons and nitrogen oxides), and PM (particulates, soot) emitted from vehicle exhaust. 2. The emission control level of the China 5 standard is equivalent to the European Union's Stage 5 emission standard currently in effect. It imposes stricter limits on nitrogen oxides, hydrocarbons, carbon monoxide, and particulate matter from vehicle emissions. From China I to China IV, each upgrade in the standard reduces vehicle pollution by 30% to 50%. The China 6 emission standard improves upon China 5 by 40%-50%, reaching a level comparable to the United States, making it one of the most stringent emission standards globally at present.