BS4 vs BS6 Norms: Key Differences and Impact on Car Insurance
India moved from Bharat Stage 4 (BS4) to Bharat Stage 6 (BS6) emission standards for newRead more
What are BS4 and BS6 Emission Standards?
Bharat Stage Emission Standards (BSES) are emission norms established by the government of India to control and reduce the levels of pollutants emitted by vehicles with internal combustion engines (ICE). In 2020, India skipped BS5 and moved straight from BS4 to BS6 norms. It introduced stricter limits, specifically for pollutants such as nitrogen oxides (NOx) and particulate matter (PM). With this transition, automobile manufacturers were required to adopt more advanced emission-control technology, including improved fuel injection systems, catalytic converters and particulate filters.
What are the Differences Between BS4 and BS6 Emission Standards?
The shift from BS4 to BS6 emission norms changed both fuel and vehicle technologies. Here is an overview of the key differences between these two emission standards:
| Parameter |
BS4 |
BS6 |
| Year of Implementation |
2017 |
2020 |
| Fuel sulphur content |
Up to 50 ppm |
Up to 10 ppm |
| Emission Limits (NOx) |
Moderate |
Diesel: 70% lower, Petrol: 25% lower |
| After-Treatment Technology |
Basic catalytic converter, EGR |
Advanced EGR, DPF, SCR |
| Fuel Injection technology |
Conventional, multi-point |
High-pressure direction injection |
| Diesel emission control |
Basic emission-control systems |
Systems such as DPF and SCR used in applicable vehicles |
| On-board diagnostics |
Optional |
Mandatory requirements and more advanced |
Impact of BS6 Norms on Vehicle Prices and Performance
Compared to older BS4 models, BS6 vehicles are generally more expensive. Their increased manufacturing costs are mainly due to significant changes in engine designs and the introduction of advanced emission control technologies to meet stricter norms.
In terms of performance, BS6 petrol cars provide refined power output and slightly improved mileage due to more advanced fuel injection systems. However, BS6 diesel cars have components like Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR) systems that require periodic maintenance and BS6-compliant fuel for optimal operation.
In the early years of BS6 implementation, some diesel car owners noticed DPF clogging while driving short distances or in heavy city traffic. But with better software programming, this issue has been addressed.
Does BS6 Impact Car Insurance?
No. The shift to BS6 emission standards does not impact car insurance directly. However, it may indirectly influence the premium costs. Here's how:
-
Higher Initial Premiums (Due to IDV)
The premium amount is calculated based on a car's IDV (Insured Declared Value), engine capacity (cc) and city of vehicle registration, among other factors. It is not determined by which emission norms the engine complies with.
Since IDV is a percentage of a car's value, a costlier BS6 car generally starts with a higher IDV than an equivalent BS4 model did, which increases the premium for the own-damage component of car insurance. Third-party insurance premiums remain unaffected, as they are fixed by IRDAI based on the car's engine capacity (cc).
-
Expensive Repair and Replacement
BS6 cars have complex exhaust systems. The Diesel Particulate Filter (DPF), SCR unit, and oxygen sensors are highly sensitive and expensive. So, if any rear-end or undercarriage collision damages the exhaust system, the replacement cost is significantly higher than it would be for a simple BS4 exhaust pipe. Car insurance companies consider this risk of expensive repairs when calculating premiums.
Key Takeaway
BS4 and BS6 indicate a vehicle's emission compliance, not its insurance coverage. If you own a BS4 car, you can continue to insure it, provided it remains legally registered and eligible for coverage. Also, before you make a purchase, it is best to explore car insurance plans online from multiple insurers to get the right policy as per your car's requirements.
