Difference Between BSIV & BSVI Engine: BS4, BS6 Performance

Every year, we see global temperatures rising due to continuous pollution. Vehicular pollution is one of the biggest factors behind this ^[1]. The Indian government has been taking various steps to tackle this problem. One of the concerns in this direction has been to limit the emission that is generated via the bikes that people ride on a daily basis. You may have heard the terms BS4 and BS6 being used repeatedly when it comes to bikes and the pollution they can cause. It is important that you understand the differences between the two terms and if it impacts the price of your bike insurance. More information for the same has been given below.

What are Emission Norms?

Before we get to the differentiation part, let us first understand what the emission norms are. Emission norms are regulations set by the government to limit the amount of pollutants that vehicles can emit into the environment. In India, the Bharat Stage (BS) emission norms are used to regulate the emissions of vehicles. In 2017, BS4 norms were introduced by the government across India. BS4 was replaced by BS6 emission norms in 2020. Here are the two major emission norms that you may find in India:

What is BS4 (BSIV)?

BS4 emission norms were introduced in 2010 in a few states before being enforced across India in 2017. It was introduced to set limits for the amount of pollutants that vehicles can emit into the environment. These norms applied to all vehicles, including cars, buses, trucks, and two-wheelers. The main pollutant controlled by BS4 norms is nitrogen oxide (NOx). BS4 norms used the Euro IV emission standards, which set limits for NOx at 80mg for petrol vehicles such as bikes. These norms also set limits for other pollutants such as hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM).

What is BS6 (BSVI)?

BS6 emission norms were introduced to replace BS4 norms in April 2020. These norms are more stringent and have even lower limits for pollutants emitted by vehicles. The main pollutants controlled by BS6 norms will be PM and NOx, just like BS4 norms. BS6 norms uses the Euro VI emission standards, which set limits for PM at 4.5mg/km and for NOx at 60mg for petrol vehicles. These limits are significantly lower than the limits set by BS4 norms. BS6 norms have also set limits for other pollutants such as HC and CO, but these limits are almost similar to the limits set by BS4 norms.

How Do BS6 (BSVI) Diesel Engines Work?

BS6 diesel engines incorporate advanced technology such as selective catalytic reduction (SCR) and diesel particulate filters (DPF) to minimise pollutants like nitrogen oxides (NOx) and particulate matter (PM). These engines use low-sulphur fuel and advanced exhaust systems to ensure that emissions are kept within strict limits. The implementation of these technologies helps vehicles comply with the stringent emission standards set under the BS6 full form norms.

Difference Between BS4 and BS6 Emission Norms

As you can see, the main difference between BS4 and BS6 emission norms is the level of pollutants that vehicles are allowed to emit into the environment. BS6 norms have been made more stringent to reduce the amount of pollutants being emitted from bikes. Therefore, the limits are lower for pollutants, particularly PM and NOx, than BS4 norms. Other points of difference include:

Parameter	BS4 Norms	BS6 Norms
Emission Standard	Permits higher levels of NOx and PM.	Drastically reduces NOx and PM levels.
Fuel Type	Higher sulphur content (50 ppm).	Low sulphur content (10 ppm).
OBD Norms	Basic OBD standards.	Advanced OBD standards with real-time data.
Technology Requirement	Conventional technology.	Advanced technology like SCR and DPF.

Difference Between BS4 and BS6 Fuels

Fuel Component	BS4 Fuel	BS6 Fuel
Sulphur Content	50 parts per million (ppm)	10 parts per million (ppm)
Engine Compatibility	Compatible with BS4 engines only.	Suitable for both BS4 and BS6 engines.
Impact on Emissions	Higher emissions due to more sulphur.	Lower emissions due to less sulphur.

What are BSI, BSII, BSIII, BSIV and BSVI Emission Norms?

1. BSI (Bharat Stage I)

Introduced in 2000, the first emission standard in India aimed to reduce pollutants from vehicles.

2. BSII (Bharat Stage II)

Launched in 2005, these norms were stricter than BSI, requiring lower sulfur levels in fuel and better vehicle technology.

3. BSIII (Bharat Stage III )

Implemented in 2010, this stage mandated further reduction in nitrogen oxides (NOx) and particulate matter (PM) emissions.

4. BSIV (Bharat Stage IV)

Enforced in 2017, these norms focused on stricter control of NOx, PM, and hydrocarbon emissions, requiring advanced catalytic converters.

5. BSVI (Bharat Stage VI)

Skipping BSV, India adopted BSVI in 2020, aligning with Euro VI standards. It mandates ultra-low sulfur fuel (10 ppm) and advanced emission control technologies, drastically reducing NOx and PM levels.

Significance 

These norms aim to curb air pollution, improve fuel efficiency, and ensure the adoption of cleaner technologies in the automotive industry.

Impact of BS6 norms

The introduction of BS6 norms had a significant impact on the automotive industry in India. Manufacturers have invested in the new technology to meet the more stringent emission limits set by BS6 norms. This has led to an increase in the cost of vehicles and insurance policies. You can use the two-wheeler insurance premium calculator to see the difference between the cost of BS4 and BS6 two-wheeler insurance. With time, BS6 norms may have a positive impact on the environment as vehicles will emit fewer pollutants into the air. This will lead to improved air quality, which will have a positive impact on public health. But more importantly, this might benefit the environment in the long run.

Impact of BS6 on CNG Cars

1. Lower Emissions: BS6 norms have significantly reduced nitrogen oxides (NOx) and particulate matter (PM) emissions, making CNG cars even cleaner.
2. Improved Fuel Efficiency: Advanced technology under BS6 ensures better combustion, enhancing mileage for CNG vehicles.
3. Advanced Engine Design: BS6-compliant CNG cars use upgraded engine components to meet stricter emission standards.
4. Higher Costs: The integration of advanced technologies has slightly increased the manufacturing and purchase cost of BS6-compliant CNG cars.
5. Cleaner Fuel Requirement: CNG cars now benefit from cleaner fuels with ultra-low sulfur content, reducing engine deposits.
6. Better Air Quality: Enhanced emission control contributes to improving overall air quality, especially in urban areas.
7. Focus on Maintenance: Regular servicing and adherence to maintenance schedules are crucial for BS6 engines to perform efficiently.

Conclusion

Overall, the BS4 and BS6 emission norms are aimed at reducing the pollution caused by vehicles, improving the overall air quality, and helping in the recovery of our environment. If you have a bike with either of the engines, it is vital to do the timely renewal of your two-wheeler insurance  to enjoy its safety and additional features. For more information on vehicle insurance and the transition to BS6 engines, you can visit the Bajaj Allianz General Insurance Company website.

FAQs

1. Why is BS4 better than BS6?

BS4 engines are simpler and more affordable. However, they emit more pollutants compared to BS6 engines, making them less environmentally friendly.

2. Can BS4 vehicles run on BS6 fuel?

Yes, BS4 vehicles can run on BS6 fuel. Using BS6 fuel in BS4 engines results in lower emissions, but there are no performance benefits.

3. Why India shifted from BS4 to BS6?

India shifted to BS6 norms to reduce air pollution and comply with global emission standards, ensuring cleaner air and a healthier environment.

4. When will BS4 stop in India?

The sale and registration of BS4 vehicles stopped in India from April 1, 2020, after the implementation of BS6 norms.

5. Is BS6 fuel more fuel-efficient than BS4 fuel?

BS6 engines are designed for cleaner emissions, but fuel efficiency largely depends on the engine tuning and driving conditions. While some BS6 vehicles may show slight improvements, others may have similar mileage to BS4 models.

6. Can BS6 fuel be used in BS4 vehicles?

Yes, BS6 fuel can be used in BS4 vehicles without issues. It has a lower sulfur content, which helps reduce emissions and can benefit the engine’s longevity.

7. Is BS6 fuel more expensive than BS4 fuel?

Yes, BS6 fuel is slightly more expensive due to the additional refining processes required to lower sulfur content.

8. Can old BS4 cars be converted to meet BS6 norms?

Converting BS4 cars to BS6 compliance is technically complex and expensive. It usually involves significant modifications that are not practical for most vehicles.

9. Do BS4 vehicles need a pollution control certificate (PUC)?

Yes, all vehicles, including BS4 models, are required to have a valid pollution control certificate as per Indian regulations. *Standard T&C apply Insurance is the subject matter of solicitation. For more details on benefits, exclusions, limitations, terms, and conditions, please read the sales brochure/policy wording carefully before concluding a sale.