What does China 5 and China 6 mean for vehicles?

[LeJosie]

China 5 and China 6 refer to vehicle emission standards, which regulate the content of harmful gases such as carbon monoxide, PM, and soot emitted from vehicle exhaust. The transition from China 5 to China 6 involves improvements in intake and exhaust efficiency, exhaust gas recirculation efficiency, etc., with the ultimate goal of reducing the levels of harmful gases. More detailed information is as follows: 1. The China 6 emission standard is an upgraded version of the current China 5 standard, imposing stricter limits on the emission of CO (carbon monoxide), THC (total hydrocarbons), NMHC (non-methane hydrocarbons), NOX (nitrogen oxides), and PM (particulate matter). It also introduces new regulations on PN (particulate number). According to estimates, under the China 6 standard, light gasoline vehicles will see a reduction of approximately 50% in CO, HC, NMHC, and NOX emissions compared to the China 5 stage, with particulate emissions reduced by about 40%. For heavy-duty diesel vehicles, NOX and particulate emissions will be reduced by more than 60% compared to the China 5 stage. 2. In addition to stricter emission requirements, the cold-start test cycle has been adjusted from the NEDC cycle under China 5 to the WLTC cycle under China 6, leading to an increase in actual emissions. Starting from July 1, 2023, the dual-idle test will be replaced with a real driving emissions (RDE) test, resulting in higher exhaust emissions. Given that vehicle exhaust accounts for 20% to 40% of air pollution in first-tier cities, implementing the China 6 standard can lead to a noticeable improvement of over 10% in urban air quality.