BS I and II Diesel Vehicles
Government has tightened the emission norms from time to time depending upon the availability of engine technology, quality of fuel made available by oil companies etc.
Bharat Stage IV
Bharat Stage IV emission norms for four wheeled vehicles have been implemented in the National Capital Region and other cities from 2010. Since then, the BS IV emission norms have been mandated across the cities and States in a phase wise manner.
It is now mandated that BS IV fuel emission norms will be applicable throughout the country by April 2017, including two wheelers and three wheelers. Furthermore, Government has proposed introduction of Bharat Stage VI fuel emission norms by the year 2020 throughout the country.
It is expected that with the new norms there will be reduction in vehicular pollution.