Why BS-III petrol and BS-IV diesel four-wheelers have been banned in Delhi-NCR
The Delhi government has implemented GRAP Stage III to combat pollution and smog, including a ban on BS-III petrol and BS-IV diesel vehicles. Bharat Stage emission norms were introduced to regulate air pollutants. India decided to adopt BS-VI norms by 2020 with hopes of ensuring an 80% reduction in sulphur levels due to vehicular emissions.