Need for Stringent Emission Limits, BS VI

Due to the worsening air quality, there is an overwhelming concern for public health, as vehicular emissions are considered a large contributor to airborne pollution. As a result, the Govt of India decided to jump straight from BS-IV norms to the Bharat Stage VI norms which came into effect from 1st April 2020 for On-road vehicles i.e 2W-Scooters & bikes, 3W-Autos, 4W-Passenger cars, Buses & Trucks. The Bharat Stage VI (BS-VI) norms put limits on emissions of CO, HC, NOx, PM (Particulate Matter) and PN (Particulate Number). The new norms reduce NOx by 89% & PM by 50% from BSIV values & in addition have a new limit on the particulate count to 8×1011 (particles/kWh).


A very important aspect for BS-VI introduction is the level of fuel refining improvements that have been made by Indian Oil Refineries to bring down the sulphur levels in the fuels.
This was necessary since high sulphur levels will be detrimental to the functioning of after-treatment Systems as Sulphur reacts with the precious metals in the catalyst and reduces their efficiency.

– Article contributed by Amogh Krishna Atreya