When did China implement the National IV vehicle standard?

[LaLayla]

National IV vehicles were introduced in 2011. The National IV emission standard was implemented starting in 2011 and remained in effect until 2018 when the National V standard was introduced. Vehicles produced between 2011 and 2017 adhered to the National IV standard. Below is an introduction to the National IV emission standard: 1. The full name of the 'National IV standard' is the National Fourth Stage Motor Vehicle Emission Standard, which is equivalent to Europe's 'Euro IV standard'. 2. The National IV emission standard is the fourth stage of China's motor vehicle pollutant emission standards. The main pollutants emitted by vehicles include HC (hydrocarbons), NOx (nitrogen oxides), CO (carbon monoxide), and PM (particulate matter). 3. The National IV standard requires that the emission levels of various pollutants be approximately 50% lower than those of the National III standard. This is achieved through the application of technologies such as improved catalytic converter active layers, secondary air injection, and exhaust gas recirculation systems with cooling devices, which control and reduce vehicle emissions to levels below the specified standards.