Delhi was recently reported as the most polluted city in the world. India currently is not very stringent on emission norms and vehicle age, however, that is all set to change.
They have now finalised that no manufacturer can sell or an individual can register a vehicle that does not pass BS-4 emission norms. It will be mandatory for vehicles to pass emission norms from April, 2017.
Most metro cities are already complying to BS-4 emission norms. Chennai, Delhi-NCR, Hyderabad, Kolkata and Mumbai are provided with vehicles that are already BS-4 compliant.
Several other cities will be soon following BS-4 emission norm. So that the entire country will be less polluted than it already is. April, 2017 is the last date for all new vehicles sold and registered to be BS-4 compliant.
BS-4 equipped vehicles cost slightly more and it is expected that sales of lower emission models will witness an increase until April, 2017. In a way, it is bad and there is currently no way to curb this problem.