Spilt the Beans BS6 Phase 2 rules for cars: A cleaner tomorrow

India’s move towards cleaner air saw a step-up with the rollout of Bharat Stage VI (BS6) emission norms in April 2020, and by 2025, the Phase 2 norms of BS6 for cars are changing the automobile landscape. Making its debut in April 2023, BS6 Phase 2 adds some extra pressure on vehicle emissions, deploying Real Driving Emissions (RDE) tests, as well as stricter limits on pollutants like nitrogen oxides (NOX) and particulate matter (PM). Phase 2 norms of BS6 for cars have started making an impact on cleaner engines, advanced technology, and a shift in market dynamics as of March 25, 2025. So, let’s dig deeper into how these norms are working towards bringing about change on Indian roads.

What Are BS6 Phase 2 Norms?

Phase 2 norms of BS6 to cars also have its impact since they have progressed beyond BS6 targets originally. Though BS6 Phase 1 brought Indian regulations in line with Euro 6 standards, BS6 Phase 2 adds Real world driving emissions (RDE) testing, which means cars will now be required to meet the emission limits under real-world driving conditions—not just in a lab.

These norms, which have been mandated by the Ministry of Road Transport and Highways (MoRTH) through the Central Motor Vehicles Rules (CMVR), set a limit for NOx at 60 mg/km for petrol cars and 80 mg/km for diesel cars, while PM limits are capped at 4.5 mg/km for diesel. The aim with the BS6 Phase 2 norms for cars is real-time compliance, which will help in providing cleaner air across the varied terrains of India.

Phase 2 norms encourage technological upgrades

The most prominent visible impact of BSVI Phase 2 norms on cars lies in what is found under the bonnet. Automakers have turned to high-tech systems to keep up with real-world emissions standards. Specific catalytic Reduction (SCR) systems using AdBlue (urea solution) have become commonplace in diesel cars to reduce NOx emissions, while Gasoline Particle Filters (GPFs) also aim to capture PM in petrol direct-injection engines.

Even though the OBD-II norms (Phase 2) for BS6 cars (which monitor emission systems in real time) have been in effect since April 2023 as per CMVR amendments, the introduction of stricter BS6 as well as PUC emissions tests raises concerns about compliance for manufacturers.

The same applies to the Tata Punch 2025, which employs a refined 1.2L petrol engine augmented with GPF, and the diesel variant of the Mahindra Thar, which works with SCR. Phase 2 norms of BS6 for cars come into effect only in 2024 and will either drive manufacturers to come up with innovative solutions or push up the cost of production by 8–10% without it, affecting performance.

Impact on Performance and Fuel Economy

We’re not just talking about how they drive either — the influence of Phase 2 norms of BS6 on cars. SCR and GPF retrofits do decrease the total output of the engine slightly, as an exhaust system in a purpose-built race car is built for emissions, not speed. For diesel cars, we are facing a bigger battle—some are losing as much as 5–7 bhp because tuning gets stricter. However, Phase 2 norms of BS6 do not necessarily bring only doom and gloom for cars. Losses are balanced by the optimized engine management systems (EMS) and hybrid tech present in models, such as the Hyundai Creta, which maintain efficiency.

Fuel economy also suffers, as diesel vehicles demand AdBlue top-ups (₹50–70/liter), which bumps up running costs. For instance,  car side makes it really important for manufactures to find a balance between mileage and compliance, which is of paramount importance when you consider India’s price-sensitive market.

The Diesel Fall and the Electric Surge

The norms on cars is having a major influence on Indian automotive industry. Diesel cars, once the stars of torque and mileage, are fading away. Stricter norms and higher compliance costs are why brands like Maruti Suzuki are set to discontinue diesel engines altogether by 2025, and will instead focus on petrol and CNG powertrains. The encroachment of Phase 2 norms of BS6 on cars is hastening this process, with diesel’s market share falling from 40% in 2019 to less than 15% in 2025.

Electric vehicles (EVs) indirectly gain. While BS6 norm has no effect on EVs, Phase 2 norms of BS6 will make conventional engines expensive, which will bridge the pricing disparity with EVs such as Tata Punch EV. With government incentives provided under the FAME II scheme, this trend is set to go even higher, and aligns perfectly with India’s 2030 clean mobility vision.

Legal Context and Compliance

BS6 Phase 2 norms do have an association with legal terms in the country which has a profound impact on cars. Applicable under the Motor Vehicles Act, 1988, and subsequently updated via the CMVR amendments in 2023, Phase 2 rules require RDE testing for type approval and Conformity of Production (CoP) checks. According to Section 182A of the Act, non-compliant vehicles will be subject to substantial fines or sales bans. This also dots with the goals for the National Clean Air Programme (NCAP) in India as these Phase 2 norms of BS6 is also in sync with the Air (Prevention and Control of Pollution) Act, 1981.

The agencies such as Automotive Research Association of India (ARAI) need to be submitted with the RDE data by automotive manufacturers and will hold their accountable. Thus, the Phase 2 norms of BS6 also have accountable implications on cars — the enforced accountability of these norms are key to protecting public health, especially in cities like Delhi, where air quality remains a continuing crisis.

Cost Implications for Buyers

 BS6 Phase 2 norms for cars, the regulations which hit consumers’ wallets. The implementation of advanced technology such as SCR and GPF escalate the ex-showroom pricing by ₹50,000–₹1 lakh depending on the vehicle model. Maintenance costs surge as well — AdBlue top-ups and OBD-II servicing cost ₹2,000–₹5,000 every year. For budget cars, such as the Maruti Suzuki Brezza, the BS6 Phase 2 norms have been a double-edged sword for affordability, though tax benefits for submeter cars help mitigate the price impact.

But that payoff in the long run is cleaner air and potentially less spent on fuel due to efficient engines. With the car industry impacted by BS6 Phase 2 norms, buyers will have to balance their initial costs against that of the environment, and this trade off becomes the tipping point for car purchases in 2025.

Environmental Benefits

The of a circular BS6 Phase 2 norms on the existing golf course is the environment. Ensuring the emissions stay as dow both urban stop-go traffic or highway cruising as low is covered by RDE testing, which cuts NOx for the new range compared to BS4 formations by 43% and PM by 82%. In cities such as Mumbai and Bangalore, where vehicular pollution is responsible for AQI peaks, the Phase 2 norms of BS6 applied to cars brings meaningful relief. Hybrid and CNG models, bolstered by these norms, further shrink carbon footprints, reinforcing India’s commitments under the Paris Agreement.

Challenges for Manufacturers

The Phase 2 norms of BS6 is not without its share of barriers for cars. Retrofitting existing models requires a huge R&D outlay — industry estimates say it will be ₹500 crore. The smaller players only lag behind, while conglomerates like Tata and Hyundai expand their adaptability. Supply chain issues — including AdBlue availability — also loom, though government mandates to stock the fluid at fuel stations alleviate such worries. BS6 Phase 2 norms, which are set to come into force just before the end of India’s fiscal 2024—will cut deep into the cars business—but in doing so it will test the mettle of brands, rewarding those with deep pockets (to invest in new powertrains) and those who have been innovative.

Future Outlook

With the introduction of BS6, the challenge now is Phase 2 norms for BS6, which will impact only the vehicles in the years to come. uniforms or the CAFE (Corporate Average Fuel Efficiency) guidelines in 2027. The National Biofuel Policy has mentioned flex-fuel options in vehicles and the move to blend ethanol as the next step that’s now been captured in the Tata Punch 2025. EVs will be gaining more acceptance, however, the improvements brought about by BS6 Phase 2 norms for cars continue to ensure that internal combustion engines are cleaner than ever while the world transitions to an all-EV future.

Conclusion

 From cleaner engines and greater costs to a diesel downturn and EV upswing, these norms are reshaping how cars are built, driven and bought. It aims to make innovating and simultaneously doing good for the environment possible, and achieving the restricted compared to the NGT in being compliant in what will be 2025. With the effect of the Phase 2 norms of BS6 on cars starting to take shape, India’s roads aren’t just getting busier; they’re going green as well.