DIFFERENCE BETWEEN BS-III EMISSION NORMS & BS-IV EMISSION NORMS
There is Lot Of Confusion Between BS III & BS IV ENGINES/VEHICLES Bharat Stage (BS) is an emission norm which is regulation in India for automobile manufacturers. Basically BS-4 is regulation for everything that is emitted from vehicle. The regulations not only covers exhaust emission but for evaporation emission, light emission, noise emission, tyre gas emission and perhaps a few more.History
The first emission norms were introduced in India in 1991 for petrol and 1992 for diesel vehicles. These were followed by making the Catalytic Converter mandatory for petrol vehicles and the introduction of unleaded petrol in the market.
On 29 April 1999 the Indian Supreme Court ruled that all vehicles in India have to meet Euro I or India 2000 norms by 1 June 1999 and Euro II will be mandatory in the North Capital Region by April 2000. Car makers were not prepared for this transition and in a subsequent judgement the implementation date for Euro II was not enforced.
In 2002, the Indian government accepted the report submitted by the Mashelkar committee. The committee proposed a road map for the roll out of Euro Based emission Norms for India. It also recommended a phased implementation of future norms with the regulations being implemented in major cities first and extended to the rest of the country after a few years.
Based on the recommendations of the committee, the National Auto Fuel policy was announced officially in 2003. The roadmap for implementation of the Bharat Stage norms were laid out till 2010. The policy also created guidelines for auto fuels, reduction of pollution from older vehicles and R&D for air quality data creation and health administration.
| Standard | Reference | Date |
|---|---|---|
| Bharat Stage II | Euro 2 | 1 April 2005 |
| Bharat Stage III | Euro 3 | 1 April 2010 |
| Bharat Stage IV | Euro 4 | 1 April 2017 |
| Bharat Stage VI | Euro 6 | April 2020 with mandate (proposed) |
Changes from BS3 to BS4 for motorcycles are more than just tailpipe emissions. Regulations also (for the first time) restrict evaporation emissions from fuel tanks, which mean a new breather value and additional or changed stamps in the body structure or additional brackets that hold these new systems. This is very difficult to retrofit considering the fact that major design changes might be needed.
Coming to tail pipe emissions, BS4 motorcycles in most cases require larger catalytic converters in terms of flow volumes to eliminate harmful nitrogen based gasses. And although that could be adapted within the exhaust system, most bikes also need a secondary airflow system that adds oxygen (or natural air) to the exhaust stream just before the catalytic convertors. This of course, is a more complex system for which retro fitment is more difficult. Many manufacturers have also resorted to a more complex ECU and ignition control setup that has more than the standard idle map and full throttle map for a better control of the ignition timing which in turn makes for a cleaner burn and thus, less pollution. The byproduct of this is also a more linear acceleration curve and better fuel economy.
Coming to tail pipe emissions, BS4 motorcycles in most cases require larger catalytic converters in terms of flow volumes to eliminate harmful nitrogen based gasses. And although that could be adapted within the exhaust system, most bikes also need a secondary airflow system that adds oxygen (or natural air) to the exhaust stream just before the catalytic convertors. This of course, is a more complex system for which retro fitment is more difficult. Many manufacturers have also resorted to a more complex ECU and ignition control setup that has more than the standard idle map and full throttle map for a better control of the ignition timing which in turn makes for a cleaner burn and thus, less pollution. The byproduct of this is also a more linear acceleration curve and better fuel economy.
No comments:
Post a Comment