India’s next vehicle emission standards would look beyond the smoke coming out of a vehicle’s exhaust. The proposed Bharat Stage VII (BS-VII) rules would also address pollution from brakes and tyres, check how well electric-vehicle batteries hold up over time, and require manufacturers to test vehicles under more realistic driving conditions.
The Ministry of Road Transport and Highways has proposed bringing in the standards gradually, starting with passenger cars from April 1, 2029, light commercial vehicles from April 2030, and buses and heavy trucks from April 2031. The draft notifications were published in October 2026. They invite public comments for 30 days from the date copies of the notifications are made available to the public. The standards could change before they are finalised.
What is changing from BS-VI to BS-VII?
India moved to Bharat Stage VI (BS-VI) emission standards nationwide in April 2020. Those rules tightened limits on pollutants such as nitrogen oxides and particulate matter and introduced real-driving emissions tests for applicable vehicles.
The proposed BS-VII standards would go beyond exhaust emissions measured in tests. They propose measuring smaller particles, checking emissions under real-world driving conditions and monitoring how vehicles’ emissions-control systems perform over time.
For passenger cars, the draft retains the principal tailpipe emission limits for carbon monoxide, nitrogen oxides and exhaust particulate matter. The proposed changes focus instead on additional emissions testing and monitoring, along with controls on pollution beyond the exhaust.
The draft proposes on-road testing with portable equipment as part of type approval from April 2030. It also provides for monitoring emissions and fuel or electric energy consumption, with requirements phased in over time.
In effect, BS-VII would place greater emphasis on how vehicles perform under real-world driving conditions and how their emissions-control systems behave over time, rather than relying only on laboratory tests.
How will exhaust emissions and particulate pollution be curbed?
For cars, the draft retains the principal limits on three main exhaust pollutants: carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM). For particulate emissions, it proposes lowering the particle-number measurement threshold from 23 nanometres to 10 nanometres, bringing smaller particles within the measurement regime.
The proposed standards also strengthen the focus on emissions under real-world driving conditions, through on-road testing with portable equipment and monitoring of emissions-control systems over time.
Under the proposed standards, a petrol car would be allowed to emit up to 1,000 mg of carbon monoxide and 60 mg of nitrogen oxides per kilometre. For a diesel car, the respective limits would be 500 mg and 80 mg per kilometre. For both types of car, the proposed limit for particulate matter would be 4.5 mg per kilometre.
Cars would also face a limit on fuel vapour escaping from the fuel system. An on-board monitoring system would have to detect specified emissions exceedances, including levels at least 2.5 times the relevant limit. The draft says the monitoring data must be available through the vehicle’s diagnostic port for vehicles manufactured from April 1, 2032.
The proposal also seeks to address particles released by brakes and tyres, rather than just vehicle exhausts. Brakes release particles as their surfaces wear down, while tyres shed material as they rub against the road.
For passenger cars, the draft proposes brake-particle limits of 3 mg per km for pure electric cars and 7 mg per km for other specified vehicle types from April 2031. The limit would be 3 mg per km across powertrains from April 2035. Tyre-abrasion requirements are proposed from April 2031, but the numerical limits are to be notified separately.
Will car engines have to change?
The draft sets emission limits and testing requirements but does not prescribe a particular engine design. The changes manufacturers may need to make to meet the proposed standards will depend on the vehicle and its existing technology.
Manufacturers will have to show that vehicles meet the proposed standards through testing and checks. Some may need to assess changes to sensors, engine controls, exhaust-treatment systems or software.
The rules also go beyond engines. Electric vehicles and plug-in hybrids would have to meet proposed battery-performance benchmarks, while manufacturers would need to demonstrate compliance with the proposed brake and tyre-particle requirements.
What about trucks, buses and light commercial vehicles?
Light commercial vehicles, such as small goods carriers, would follow a year after cars, from April 2030. The draft sets category-specific emission limits, with requirements varying by vehicle weight. Their brake-particle requirements would begin in April 2032, with a common limit across powertrains proposed from 2035. The numerical limits are to be notified separately.
Buses and heavy trucks are covered by a separate draft and would be brought in from April 2031. Because they do much heavier work than cars, their exhaust limits are expressed against the energy produced by the engine, rather than the distance driven. The draft sets limits for nitrogen oxides and particles, and also for gases such as ammonia, methane and nitrous oxide.
The heavy-vehicle rules would come in stages. Exhaust limits, on-road testing and onboard monitoring are proposed from April 2031. From April 2033, the draft proposes additional monitoring and brake-particle requirements. Tyre-abrasion requirements are proposed from April 2035. The numerical limits for brake particles, tyre wear and battery performance are to be notified separately.
The draft also proposes emissions-durability requirements for buses and trucks, with periods varying by vehicle category and weight. The longest proposed period extends to 875,000 km or 15 years.
What is in store for older vehicles?
The proposed BS-VII standards set new emission and testing requirements for vehicles manufactured from the specified dates. They do not set out a nationwide programme to retrofit or replace existing BS-VI cars.
For passenger cars covered by the draft, emissions compliance would be checked over the vehicle’s lifetime. The proposed main period is up to 160,000 km or eight years, whichever comes first, followed by an additional period extending to 200,000 km or 10 years.
What will the rules mean for electric cars?
The draft sets battery-energy performance benchmarks for applicable electric vehicles and plug-in hybrids. Batteries would have to retain at least 75% of their original energy capacity after five years or 1,00,000 km, and at least 67% after eight years or 1,60,000 km, whichever comes first at each stage. However, the detailed minimum-performance requirements and test procedures for battery durability are to be notified separately.
The proposal also includes an Environmental Vehicle Passport, which would give vehicle users access to up-to-date information on fuel consumption, traction-battery health and pollutant emissions, including data generated by onboard systems and monitors. The draft also requires the passport to be displayed inside the vehicle.
What have manufacturers said?
Automakers have reportedly been considering seeking a later start for the proposed BS-VII emission standards, along with a phased rollout in 2032 and 2035. They have cited the technological changes involved and what they view as inadequate lead time to prepare for the new requirements.
The proposed timelines could affect vehicle-launch schedules and add to the cost of testing, certification and compliance. Industry concerns have reportedly also included the possibility that engineering resources needed to meet BS-VII requirements could be diverted from electric-vehicle development.