What are China 5 and China 6 vehicles?

[StCharlotte]

China 5 refers to the National Fifth Stage Emission Standards for Motor Vehicles, abbreviated as China 5 Emission Standards. The China 6 standard is divided into China 6a and China 6b standards. Compared to the China 5 standard, China 6a only requires lower carbon monoxide emissions. The China 6b standard is more stringent than China 5 in all aspects. China 6a serves as a transitional phase from China 5 to China 6, with China 6b expected to be implemented by 2023. Below are the differences between China 5 and China 6: 1. The China 6 standard imposes 40% to 50% stricter emission limits compared to China 5. 2. China 6 adopts a fuel-neutral principle, meaning emission limits are the same regardless of the fuel type. In contrast, under China 5, diesel and gasoline vehicles had different emission standards. 3. Compared to China 5, China 6 reduces nitrogen oxides (NOx) by 77% and particulate matter (PM) by 67%. It also introduces a limit on particulate number (PN) and tightens requirements for emission control device durability and on-board diagnostics (OBD). 4. China 6 enforces stricter compliance and regulatory requirements, including type approval and information disclosure, production conformity checks, new vehicle inspections, and in-use compliance checks, while simplifying the compliance determination method.