What is BS4 (BSIV)?
The Bharat Stage Emission Standards (BSES) is an organisation that manages regulations imposed on emissions from all types of vehicles in India. It established the first emission norm in the year 2000, known as ‘India 2000’. Following this, BS2 and BS3 were introduced in the year 2005 and 2010, respectively.
BS4, also known as BS-IV, came into effect from 2017 and primarily focused on making emission standards more stringent. From all the regulations managed by the BSES, some of the emission-related changes involve tailpipe emission, Electronic Control Unit (ECU), ignition control, and so on.
What is BS6 (BSVI)?
As we mentioned earlier, BSES manages the output of emissions from vehicles in India. The standards to maintain this output is set by the Central Pollution Control Board which is further governed by the Ministry of Environment, Forest and Climate Change.
The BS6 emission standard, as the name suggests, is the sixth iteration of the norm. It further pushes to reduce pollution across the country compared to the current BS4 standard.
The Difference Between BS4 and BS6?
Here are a few key differences between BS4 and BS6 emission norms –
- With the implementation of BS6 standards, the Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) have been established as well. This was previously not present in the BS standard.
- Along with the implementation of BS6 emission norms, India is all set to introduce the Real Driving Emission (RDE). It is said to measure the real-time emission of the vehicles against the laboratory conditions.
- The Onboard Diagnostics (OD) is now mandatory for all vehicles under the BS6 emission norm.
- With the introduction of BS6 emission norms, there is also a change in the fuel used in the vehicles. So, the vehicles that are BS6 compliant will require BS6 fuel. If the vehicles happen to use the BS4-grade fuel, it will not adhere to the BS6 emission norms. Likewise, if the BS4 compliant vehicles use the BS6 fuel, its engine will be affected and increase the emission.
- Another crucial difference between the two is in terms of Sulphur and Nitrogen Oxide emitted. The Sulphur trace in BS6 fuel is five times lesser than the ones in BS4 fuel. Moreover, nitrogen oxide levels of BS6 diesel and petrol engines are said to be brought down by 70 percent and 25 percent, respectively.
To understand the difference between the permissible emission norms of BS4 vehicles and BS6 vehicles, consider the following table –
|Fuel Type||Pollutants||BS4 (BSIV)||BS6 (BSVI)|
|Petrol-Based Vehicles||Nitrogen Oxide (NOx)||80 mg||60 mg|
|Particulate Matter (PM)||~||4.5 mg/km|
|Diesel-Based Vehicles||Nitrogen Oxide (NOx)||250 mg||80 mg|
|Particulate Matter (PM)||25 mg||4.5 mg/km|
|HC + NOx||300 mg/km||170 mg/km|
What are BSI, BSII, BSIII, BSIV, and BSVI Emission Norms?
The Bharat Safety Emission Standard (BSES) manages the pollutant emission from vehicles running on the Indian roads. As we mentioned before, the permissible emission levels are set by the Central Pollution Control Board that works under the Ministry of Environment, Forest and Climate Change.
The standard is denoted by an abbreviation ‘BS’ – which stands for Bharat Stage. It is followed by the iteration of the respective emission norm. The emission levels in India are based on the European Norms, also known as EURO 1, EURO 2, and so on.
The first standard was implemented in India in the year 2000 and is known as ‘India 2000’. The BSII (BS2) and BSIII (BS3) standards were introduced in the year 2005 and 2010, respectively. The BSIV (BS4) emission standard was introduced in the year 2017.
Since there was a significant delay between the implementation of BSIII and BSIV standards, the introduction of the BSVI standard was fast-tracked instead of BSV (BS5). As a matter of fact, each iteration imposes more stringent permissible emission standards compared to the previous one.
To get an overview of the emission standards implemented along with their timelines, consider the following table –
|Emission Standard||European Norm Reference||Implementation Year|
|India 2000||EURO 1||2000|
|Bharat Stage II (BS2)||EURO 2||2005|
|Bharat Stage III (BS3)||EURO 3||2010|
|Bharat Stage IV (BS4)||EURO 4||2017|
|Bharat Stage V (BS5)||EURO 5||Skipped|
|Bharat Stage VI (BS6)||EURO 6||2020|
What are The Benefits of BS-VI Engine?
The advantages of moving from BS4 to BS6 compliant vehicles are as follows –
- The BS6 emission norms are said to reduce the nitrogen oxide emission by 25 percent in petrol cars
- Due to upgrade in the engine control software, there is an ever more precise fuel injection control for further cleaner emission control
Over To You
We believe that this article helps you understand the difference between BS4 and BS6 engines. So, if you are planning to buy a new vehicle this year, choosing the engine power will be no hassle.
Just like choosing between BS4 and BS6 engines is imperative to stay safe on the Indian roads, so it is essential to choose a vehicle insurance plan. Selecting the right car insurance plan will allow you to safeguard your vehicle in case of an accident financially. In fact, you can compare different plans online and then choose the one that fulfils all your requirements.
Q: What if BS4 compliant cars are filled with BS6 fuel?
A: If the BS4 compliant vehicles are filled with BS6 fuel, it may affect the engine and increase the emission.
Q: Can BS6 compliant cars run on BS4-grade fuel?
A: Although the BS6 compliant vehicles can run on BS4 fuel, it will not comply with the BS6 emission norms.
Q: Between BS6 fuel and BS4 fuel – which is cheaper?
A: The costs of BS6 and BS4 fuels do not have a significant difference. However, after BS6 fuel is implemented across the nation, the prices may fluctuate. This is due to input costs incurred by the Oil Marketing Companies (OMCs) when updating facilities on their side.
Q: Is it possible to convert my old car to fit the BS6 emission norms on my own?
A: No. It is illegal to convert your old car to fit the BS6 emission norms.