Looking at the Difference between BS-IV and BS-VI Emission Norms

Emissions are gases released by vehicles during fuel combustion, which is necessary for vehicle operation. These emissions include pollutants such as Carbon Monoxide (CO), Nitrogen Oxides (NOx), Hydrocarbons (HC) and Particulate Matter (PM). High levels of these pollutants contribute to air pollution, smog and environmental damage, while also affecting public health and overall well-being.

However, the levels of these pollutants can be controlled and reduced through improved vehicle technologies and stricter regulations. To manage vehicle-related pollution more effectively, governments across the world have introduced emission standards that regulate the amount of pollutants vehicles are allowed to release.

The Bharat Stage (BS) Emission Standards are India’s emission control norms regulated by the Central Pollution Control Board (CPCB) under the Ministry of Environment, Forest and Climate Change. These standards are similar to the European Emission Standards, commonly known as Euro norms.

Introduced in 2000, the Bharat Stage system has progressed through multiple phases, with each stage becoming stricter than the previous one. These standards specify the maximum level of pollutants a vehicle is allowed to emit, helping reduce air pollution and control harmful emissions such as Particulate Matter (PM).

Below are key Bharat Stage Emission Standard details: 

The Indian government introduced Bharat Stage 4 or BS 4 in 2010. Initially, Bharat Stage emission norms were implemented in the National Capital Region (NCR) and 14 other cities due to rising air pollution levels. Increasing pollution was affecting daily life and creating serious public health concerns in these regions. Later, in 2017, the standards were implemented across the country.

The nationwide implementation encouraged automobile manufacturers to adopt more advanced engine technologies and cleaner fuel systems. It also promoted the use of cleaner fuels among consumers, helping reduce vehicle emissions and contribute to better air quality over time.

The Indian government skipped the implementation of BS V norms mainly to accelerate the shift towards stricter emission standards and address worsening air pollution levels more effectively. The nationwide transition from BS III to BS IV took longer than expected, while pollution levels continued to rise in several cities across the country.

During this period, regions such as Delhi and the National Capital Region (NCR) experienced severe air quality issues that significantly affected public health and daily life. In some instances, schools and public activities were disrupted due to hazardous pollution levels. To respond more aggressively to these environmental concerns, the government decided to move directly from BS IV to BS VI emission norms instead of introducing BS V separately.

Bharat Stage VI (BS VI) norms are currently the latest emission standards implemented in India. They were first introduced in Delhi in 2018 and later expanded across the National Capital Region (NCR) in 2019 due to rising air pollution levels. In 2020, the Indian government implemented BS VI norms nationwide.

Initially, compliance with BS VI standards was not mandatory for all vehicles. However, the Supreme Court later prohibited the sale and registration of BS IV-compliant vehicles, reinforcing the country’s transition directly from BS IV to BS VI norms.

The primary objective of BS VI norms is to reduce harmful vehicle emissions, especially pollutants such as nitrogen oxides (NOx) and particulate matter (PM). To achieve this, automobile manufacturers adopted advanced emission control technologies such as Diesel Particulate Filters (DPFs), Selective Catalytic Reduction (SCR) systems and Lean NOx Traps (LNTs) in vehicles.

BS VI-compliant vehicles are also designed to run on BS VI fuel, which contains significantly lower sulphur levels compared to earlier fuel standards. Lower sulphur content helps reduce harmful emissions and supports cleaner vehicle operation.

The following are key pointers to understand the difference between BS4 vs BS6:

The Bharat Stage (BS) Standards system is India’s vehicle emission framework aimed at controlling vehicular pollution. Each stage introduces stricter emission norms than the previous one to help reduce air pollution. BS VI is the latest emission standard in India and focuses on cleaner fuels, advanced engine technologies and lower harmful emissions.

With these advancements, vehicles are becoming more sophisticated, making it equally important for owners to ensure adequate protection. Thus, vehicle owners can explore SBI General Insurance motor insurance solutions to safeguard their vehicles alongside staying informed about evolving regulations.

1. What is the major difference between BS-IV and BS VI norms?

The difference between BS IV and BS VI norms lies in parameters such as particulate matter emissions, sulphur content, nitrogen oxide levels, and hydrocarbon emissions. BS VI has s lower levels of these pollutants, helping reduce emissions and control air pollution.

2. How to check if a car is BS4 or BS6?

Reaching out to the car manufacturer can help you know if the car is BS4 or BS6.

3. How much difference in pollution is there between BS4 and BS6?

The main difference between BS4 and NNS6 is that BS4 results in lower pollution levels compared to BS6 due to the adoption of advanced emission control technologies and reduced pollutant content in fuel. 

4. Can I convert BS4 to BS6?

Get in touch with the car manufacturer to find out whether you can convert your BS4 car to BS6. 

5. Can I use BS6 fuel in a BS4 car? 

Ideally, BS VI fuel should not be used in a BS IV vehicle, as it may lead to fuel-related issues. It is best to confirm with your local garage or manufacturer for details.