When was the China IV emission standard implemented?

[StJasmine]

The implementation time of the China IV emission standard is: From July 1, 2013, 19 regions including Beijing, Shanghai, Guangzhou, Shenzhen, Nanjing, Urumqi, and Lanzhou strictly enforced the China IV standard. The nationwide implementation of the China IV emission standard began on January 1, 2014. Extended content: The characteristics of the China IV standard are: The China IV standard is based on the Euro IV vehicle emission standard, with China's Phase 4 standard further reducing emissions by 60%. To ensure that vehicles stably meet the emission limit requirements during use and guarantee the durability of vehicle emission control performance, additional requirements for onboard diagnostic systems and in-use vehicle compliance were introduced.