Every country has a legislation norm for the vehicles ‘ emission standards.Different countries have come up with a set of rules or laws that define as to what amount of pollution or emission quantity can be emitted by any vehicle that plies on the roads. These Emission norms / legislation is what is known as the Bharat stage emission norms in India.
Owing to the increasing pollution caused by the exhaust produced by numerous vehicles on the road, it became imperative that increased levels of pollution would be detrimental to the health of the urban dwellers. With high amounts of noxious gases such as NO2(nitric oxides) and fine particulate matter(carbon particles) that were attributed to cause lung and breathing disorders, the first of the emission norms were released in Europe and US.
The European norms are known as EURO –I,II,III,IV ,V ,where the number indicates the improved and more recent standard. Similarly U.S has its own norms that are known as US OBD(on board diagnostic) norms. Bharat stage norms closely follow the EURO norms that are specified for the Diesel and Gasoline vehicles. In effect bharat stage –IV that was introduced on April 1 in 13 cities of India is closely following the EURO-IV regulations. The only difference is that EURO-IV was introduced a few years ago in Europe and India still lags behind in implementing the norms.
The norms are based on a calculation of quantities of gases and pollutants emitted,basically measured in ppm(parts per million) or grams per cm3(volume). Any change in the Bharat stage norms usually demands a change or upgrade in the existing Engines as the norms demand a cleaner fuel and lean exhaust gases.
Many Indian car manufacturers have not yet upgraded to Bharat Stage-IV. Although cars such as the latest Swift Vdi, Ritz, Hyundai I20 and newer models are all conforming to Bharat Stage –IV, older existing models such as the Ford ikon, Older Skoda variants , Indicas and most of the commercial vehicles and trucks have still not reached bharat stage –IV compliance in India.