In which year was China 5 implemented?

[LeCooper]

China 5 was implemented nationwide starting from 2017. Below are two related introductions about China 5: 1. Introduction one: It aims to control and reduce vehicle emissions, with later standards being more energy-efficient and emission-reducing. Compared to the fourth-stage standards, the implementation of China 5 standards will significantly reduce vehicle pollutant emissions. 2. Introduction two: New vehicles can reduce nitrogen oxide and particulate emissions by 25% and 80% respectively, while in-use vehicles can reduce overall emissions by 10% to 15%, which is of great significance for improving air quality.