Vehicles release harmful gases like carbon monoxide, nitrogen oxides, and particulate matter that pollute the air and damage health. To control this, India follows Bharat Stage (BS) emission norms, with BSVI being the latest standard since April 2020.

BSIV, introduced in 2017, allowed higher emissions compared to BSVI. For example, BSIV diesel engines emitted 0.25 g/km of nitrogen oxides, while BSVI reduced it drastically to 0.06 g/km. Petrol vehicles under BSVI must also meet tighter limits, with hydrocarbon and nitrogen oxide discharge reduced from 0.18 g/km to 0.16 g/km.

Fuel quality also improved. BSIV fuel had 50 parts per million (PPM) sulphur, whereas BSVI fuel contains only 10 PPM, making it much cleaner. This not only cuts pollution but also improves engine life.

Overall, BSVI engines and fuels are around 25% cleaner, reducing pollutants by up to 82% in diesel cars. While BSIV was a step forward, BSVI is a major leap toward cleaner air and a healthier environment.