Explained: Bharat Stage IV emission norms and the history behind it

How does BS-IV differ from BS-III and why are automobile manufacturers worried

In a move that is likely to have huge repercussions on the automobile industry, today, the Supreme Court banned the sale of Bharat Stage III vehicles with effect from April 1.The verdict came on pleas seeking a ban on sale and registration of BS III-compliant vehicles from April 1, when BS IV emission norms will come into force.

Centre had earlier backed auto manufacturers who said they had unsold stock of about 8 lakh vehicles that do not meet BS IV emission norms. The companies had suggested the government deadline for 1 April 2017 was for stopping manufacture of BS