Difference between BSIV & BSVI Engine: BS4, BS6 Performance

In order to prevent environmental damage, the Central Pollution Control Board(CPCB) introduced the Bharat Stage Emission Standards(BSES). It is a mandatory set of regulations that limits the amount of emission from four-wheelers and two-wheelers. All of these efforts were taken to prevent the rampant increase of pollution in our atmosphere. It is to everyone’s knowledge, that how dire the condition of air quality is in our capital city. But it is not only limited to one city, but the whole country is under threat. According to this regulation, automobile manufacturers must sell only BS VI Engine vehicles. But what is the BS VI engine anyway? In this blog know all the details about this engine and how it differs from BS IV engines.

What Exactly is BSES and BS VI Engine?

Let us give you some background on BSES whose full form of BSES is Bharat Stage Emission Standards. It was first introduced in the year 2000 and for that, this first emission norm was dubbed as ‘India 2000’. Later down the line, BS II was introduced in 2005 and in 2010, BS III was introduced. After seven years, in 2017, BS IV was materialised into existence which came with stricter emission norms.

In recent years, the Central government skipped BS V and jumped straight to BS VI. It is an even more strict emission norm that mandates vehicle brands to sell only BS VI vehicles starting from 1st April 2020. The regulations also made the output of pollution limited by determining the permitted level within the accepted standards. Now let’s look at the difference between BS IV and BS VI engines in terms of emission levels.

Difference in Terms of Emission Norms Between BS IV and BS VI Engine

BS IV norms were introduced in 2017 which is not too long time ago. However, due to the rising pollution levels in the country, the Central Pollution Control Board introduced new norms that prohibit BS IV vehicle sales from 1st April 2020. Thus, to limit the pollutants emitted by vehicles from spark ignition and internal combustion engines. In BS IV petrol engines, the permissible amount of pollutants Nitrogen Oxide is 80mg. In diesel engines, it is 250mg/km for Particulate Matter(PM) and 300mg/km for HC + NOx.

On the other hand, in the BS VI engine, the amount was reduced to 60mg or 4.5mg/km in patrol vehicles. The amount of pollutants was reduced from 250mg/km to 80mg/km on diesel engines. The allowable limit for particulate matter in both petrol and diesel vehicles was capped at 4.5mg/km. However, the limit on HC + NOx in diesel vehicles was 300mg/km in BS IV. This was reduced to 170mg/km in the BS VI engine emission norms.

Other changes that were introduced in BS VI engine from BS IV with the introduction of the Particulate Filter (DPF) and the Selective Catalytic Reduction (SCR). This was used to monitor the levels of emission in BS VI vehicles. Furthermore, On-Board Diagnostic was also introduced in BS VI and later Real Driving Emission(RDE) which was responsible for monitoring regulations on a real-time basis. None of these aforementioned features were available in BS IV.

What are RDE and ODB in BS VI Engine?

Real Driving Emissions (RDE) is a testing that measures the emission levels in a BS VI vehicle. Before this technology came along, BS IV engines had to be tested by laboratory methods. But RDE made it possible to test vehicle better while ensuring that they meet emission standards not only in controlled environments but also in actual driving scenarios.

On the other hand, BS VI also came with the OBD or On-Board Diagnostics system. This is used to monitor the performance of the emission control devices in real-time. The main purpose of this system is to alert the driver of any kind of malfunction as well as ensure timely maintenance and compliance with emission norms.

Major Difference in Fuel in BS IV and BS VI Engine

What distinguishes BS IV and BS VI engines is the different types of fuel they consume. BS IV consumes 50ppm Sulphur concentrated fuel, which was reduced by fivefold in BS VI engine, merely 10ppm. This made BS VI a lot more cleaner than BS IV. Making BS VI emit less amount of harmful pollutants from Sulphur. This feature alone makes BS VI a lot more environmentally friendly than BS IV.

But why is Sulphur used in engines in the first place? Well, the Sulphur is required in engines to help in the lubrication process. Where these two engines differ is their types of Sulphur usage. BS IV uses actual Sulphur for lubrication whereas BS VI utilises compounds that provide similar lubrication. Therefore, BS VI has the means to replace the direct use of Sulphur and uses compounds that reduce the amount of the chemical to a mere 10ppm.

Benefits of BS VI Engine in Comparision to BS IV

One of the obvious benefits that you will notice in BS VI engine is an increase in fuel efficiency. These engines are designed to be more fuel efficient by giving more mileage while consuming less fuel. This can take place thanks to better combustion technology and in-built emission control systems. This also ensures smooth operation as lower amount of Sulphur fuel is used.

BS VI engine comes with advanced filters that lead to smoother engine operations. This helps to reduce the pressure on the engines, leading to less wear and tear. Additionally, BS VI engine also comes with advanced technology like turbocharging and direct injection. Such advancements help to maintain longer engine performance while meeting emission standards. Thus, such features enhance the overall driving experience.

Conclusion

Thus, it can be seen that the transition from BS IV to BS VI engine is a great step towards better environment. With technologies like RDE and OBD, emission levels can be measured in real time and kept under permissible limits. Currently India is progressing towards cleaner and more efficient transportation and BS VI engine is positioning to be a crucial player in that endeavour.