BS4 stands for Bharat Stage 4, as per the Central Pollution Control Board. In 2010, the board released BS3, which BS4 followed in 2017. The standard controls in this version were much stricter than the older norms. The BS4 rules cover all the standard protocols needed for the vehicle, such as engine emission, governing body and electronic control unit. One of the most significant changes in the BS4 model was the implementation of AHO, which stands for Automatic Headlight On. This was popularly applied to the two-wheelers and contributed significantly towards the safety measures.
After the implementation of BS4 in 2017, the board skipped the BS5 version. The BS6 version is meant to regulate the pollution emitted by vehicles. As per this version, there have been set levels of emissions permitted in a vehicle. This has been categorised differently for each type of vehicle for more accuracy. If your vehicle emits pollution beyond these levels, you need to get your vehicle checked immediately. If the problem persists, you should consider changing your vehicle, as you might face legal complications. As per the Union Ministry of India, this change shall reduce the pollution levels of vehicles by 80-90%. As per the Government of India, a mandated protocol is issued, which goes by the name Bharat Stage. These protocols were introduced to check vehicles and monitor their emissions effectively. It was implemented to keep a check on air pollution levels. Read More : Difference Between CGST, SGST And IGST
While understanding the BS4 vs. BS6 difference, a significant comparison can be made based on the engine and the fuel emissions of the vehicles. After the BS4, the Bharat Stage 5 was omitted, and the BS6 was introduced directly into the market. Here are the major BS4 vs BS6 differences in the engine and fuel emission. BS IV BS VI Fourth emission iteration Sixth emission iteration Fuel can only be used in BS IV vehicles, and cannot be used in vehicles with BS VI engines. Fuel can be used in both BS IV and BS VI vehicles. Not Applicable Introduction of Real Time Driving Emissions (RDE) Not Mandatory Mandatory onboard diagnostics Introduced in 2017 Introduced in 2020
After every few years, the board of Bharat Stage Emission Standards evaluates the existing version of norms that govern the aspects of a vehicle, such as their engine and fuel emission. Since these factors contribute significantly to the environment and ever-increasing pollution, certain steps are being taken to reduce these vehicles' harmful emissions. In 2017, as per the newer norms, the catalytic converter was added to the vehicles. This helped in reducing nitrogen-based emissions. In the next version, the BS6, carbon monoxide (CO) emissions from vehicles' tailpipes were reduced as per this standard. So, vehicle owners must have a certificate from the pollution control unit to drive their vehicles. This certificate entitles vehicles to follow the BE6. Fuel Type Pollutant Gases BS6 (BSVI) BS6 (BSIV) Petroleum Distillate Vehicle Nitrogen Oxide (NOx) Limit 60 mg 80 mg - Particulate Matter (PM) Limit 4.5 mg/km - Diesel Fuel Vehicle Nitrogen Oxide (NOx) Limit 80 mg 250 mg - Particulate Matter (PM) Limit 4.5 mg/km 25 mg - HC + NOx 170 mg/km 300 mg
The new government-mandated BSI, BSII, BSIII, BSIV, and BSVI norms are guidelines issued to reduce vehicle emissions. Aimed at capping release of harmful gases from vehicle exhausts, details of these norms are shared below:
All of the above have played a crucial role over the years in reducing vehicular pollution, improving air quality, and fostering the development of cleaner and more sustainable technologies in the automotive industry.
Check out the BS6 two-wheelers/bikes/scooters available in the Indian market now:
Model Engine Mileage Emissions Honda SP 125 123.94 cc 65 kmpl BS6 Bajaj Platina 110 115.45 cc 70 kmpl BS6 Hero HF Deluxe 97.2 cc 70 kmpl BS6 Bajaj Platina 100 102 cc 70 kmpl BS6 TVS Star City Plus 109.7 cc 66 kmpl BS6 Hero Splendor Plus 97.2 cc 0 kmpl S6 onda Shine 125 23.94 cc 5 kmpl S6 Honda CB Unicorn 150 162.7 cc 60 kmpl BS6
Model Engine Fuel Efficiency Emissions Honda Activa 6G 109.5 cc 47 kmpl BS6 Suzuki Access 125 124 cc 46 kmpl BS6 Honda Dio 109.51 cc 45 kmpl BS6 TVS Ntorq 125 124.8 cc 42 kmpl BS6 Yamaha Fascino 125 125 cc 49 kmpl BS6 Hero Maestro Edge 125 124.6 cc 45 kmpl BS6 Hero Destini 125 124.6 cc 50 kmpl BS6 TVS Scooty Pep Plus 87.8cc 68 kmpl BS6 Read More : Electric Vs Petrol Scooter
Now that you know the difference between BS4 and BS6 vehicles, it’s time to upgrade to the latest BS version bike. The latest BS version vehicles greatly contribute to the environment as they help control pollution levels. However, upgrading or buying a new two-wheeler will also impact your budget. So, why not get bike finance from Muthoot Capital Services? They provide the best bike loan interest rates. With Muthoot Capital Services, you can easily pay off your bike's value with lesser down payment options and monthly instalments.
In terms of power, the difference between BS4 and BS6 vehicles is as good as negligible. Norms for both focus on reducing emissions, and ignore engine performance. BS6 engines, though, may slightly reduce power output due to stricter emission controls.
In terms of fuel efficiency, BS6 vehicles are considered less fuel-efficient than BS4. Stricter emission norms require additional components like catalytic converters, slightlyly impacting fuel economy.
Bharat Stage 4 is the full-form of BS4.
Bharat Stage 6 is the full-form of BS6.
The next expected emission norm after BS6 in India is expected to be the BS7. BS7 is expected to further introduce stricter pollution controls and advanced emission technologies.
BS5 was skipped and BS6 was launched directly by India after BS4 for a quicker transition towards cleaner and more advanced technologies. The move was made with the intention of aligning as fast as we could with global Euro 6 standards to combat severe air pollution.
Yes. It is mandatory for BS4 vehicles to have a Pollution Under Control (PUC) certificate, to ensure compliance with emission norms.

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