What are the symbols for emission standards from National I to National VI?

[LeOwen]

The symbols for emission standards from National I to National VI are: I, II, III, IV, V, VI. Additional information is as follows: 1. Implementation of vehicle pollutant emission standards: The purpose is to reduce vehicle exhaust emissions and environmental pollution. Vehicle exhaust refers to harmful gases such as CO (carbon monoxide), HC (hydrocarbons), NOx (nitrogen oxides), and PM (particulates, soot) emitted from the exhaust. 2. The country has currently introduced the National VI emission standard: Compared to the National V emission standard, the National VI emission standard is considered a relatively strict emission standard. The National VI emission standard is divided into two phases, namely National VIa and National VIb, which are planned to be uniformly implemented nationwide on July 1, 2020, and July 1, 2023, respectively.