Conversation so far:
when were manufacturer responsibility regulations for heavy vehicles introduced in china
China first implemented nationwide emission standards for heavy-duty vehicles in 2000 (China I) for diesel and in 2003 (China I) for gasoline.
what were china's emissions standards for heavy duty vehicles based on
Emission standards for new heavy-duty truck and bus engines in China follow the European precedent.

Question: how long does it take to implement new standards
Self-contained rewrite: how long does it take for china to implement new emissions standards for heavy duty vehicles