What are China III, China IV, and China V?

[Robert]

China III, China IV, and China V are exhaust emission standards. Engine displacement is an important parameter for measuring a vehicle. The volume of space that the piston moves from top dead center to bottom dead center is called cylinder displacement. If the engine has multiple cylinders, the sum of the working volumes of all cylinders is called the engine displacement. Exhaust gases contain 150 to 200 different compounds. Since vehicle exhaust emissions are mainly released between 0.3 meters and 2 meters, which is exactly within the human breathing range, they cause significant harm to human health. The most harmful components include carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and solid suspended particles (PM). Vehicle emission standards are national regulations established to control the emission of harmful gases such as CO (carbon monoxide), HC and NOx (hydrocarbons and nitrogen oxides), and PM (particulates, soot) from vehicle exhaust.