New Delhi: The Centre has issued an order that updates norms for piston rings – a key component of internal combustion engines (ICE) – to help reduce carbon emissions, replacing standards that had been in place since 1977. The new standards came into effect on 10 February, said the order dated 12 February.
Experts said the cost impact for most automakers was likely to be limited, as many already follow similar global specifications. However, smaller component manufacturers may need to upgrade materials and testing processes to comply with the new norms, they said.
Piston rings help reduce emissions by ensuring fuel burns cleaner and more efficiently, so these updated specifications by the Bureau of Indian Standards (BIS) are a significant development for the world's third-largest automobile market. These rings have an important role to play in controlling the amount of lubricating oil on the cylinder wall, ensuring that excess oil is scraped back into the crankcase while maintaining enough lubrication for smooth engine operation. The transport sector accounts for around 14% of India’s GHG and particulate matter emissions.
The updated standards incorporate revised dimensional tolerances, material requirements and testing procedures, and are part of the government’s plan to bring conventional ICE vehicles at par with global manufacturing standards, said a government official who did not wish to be named. They added that the need for new standards stems from significant developments in engine design, materials science, stricter emission norms, and higher fuel-efficiency requirements.
The revised specifications are also aligned with internationally accepted engineering and quality benchmarks, and will make Indian automotive components easier to compare and integrate with global supply chains, the official said.
Earlier standards under IS 8422 (parts VI, VII and VIII) covered different types of slotted oil control rings for internal combustion engines. These will be withdrawn on 10 August 2026, giving manufacturers a six-month transition period. The government official cited above said, “The new standard updates and consolidates specifications based on modern design and performance expectations. Instead of covering only slotted oil control rings, the revised framework now includes a wider range of piston ring designs and configurations used in contemporary engines.”
Queries sent to the BIS, and ICE vehicle makers Maruti Suzuki, Tata Motors, Mahindra & Mahindra, Hyundai, and Kia remained unanswered till press time.
‘Will help advance industry’
India’s auto parts industry, worth about $116 billion in 2026 according to market research firm Mordor Intelligence, is largely made up of micro and small enterprises. “For MSME manufacturers, updating these standards is important as it helps align their production with modern engine technologies and evolving industry requirements. It will also help MSMEs improve product quality and stay competitive in both domestic and global supply chains,” said Vinod Kumar, president, India SME Forum.
Auto industry executives said the move indicated that regulatory upgrades for internal combustion engines would continue even as the country accelerated its transition to electric mobility. They argued that technical standards often play a key role in improving safety, performance and manufacturing quality across the automotive sector.
Jaideep Wadhwa, managing director, Sterling E-Mobility Solutions Ltd, said government regulations facilitating industry upgrades have helped improve vehicle safety and technological standards. “The government facilitates the industry and the new norms introduced are very useful. Take the case of seat belts, airbags and several other measures. All of them have proved useful over time. Similarly, these standards for internal combustion engines will also help advance the industry,” he said.
Environmental experts said improvements in engine components that affect combustion efficiency play an important role in reducing vehicular emissions and air pollution. Harjeet Singh, a climate expert and founding director of the Satat Sampada Climate Foundation, said the government's move was a pragmatic step toward immediate emissions reduction. “In a country where millions of internal combustion vehicles will remain on the road for the next decade, every percentage point of friction reduction and fuel efficiency counts as a win for our climate targets and urban air quality,” he said.
“This focus on continuous greening of the existing supply chain is vital for a just transition. It provides a lifeline to the millions of workers in India’s massive auto-component sector, allowing for a phased skilling process and avoiding major manufacturing disruptions,” Singh added.
He cautioned, however, that such technical refinements to fossil-fuel engines must remain a bridge, not a destination. “The automotive industry must not use these efficiency gains as a pretext to lock in internal combustion technology or delay the inevitable and urgent transition to full electric mobility,” he added.
Dr Anil Prakash Joshi, an environmentalist and Padma Bhushan awardee, said, “This is a very good step by the government because vehicles are a major contributor to carbon emissions and air pollution. When one litre of petrol or diesel is burned, it produces 1.5 to 2 kg of carbon dioxide. The piston ring plays a very important role in combustion efficiency.”
“If better piston ring design allows the engine to produce more energy with lower fuel combustion, it can reduce emissions and have a positive impact on the environment,” added Joshi, founder of Himalayan Environmental Studies and Conservation Organization (HESCO).
Clean mobility experts agreed, saying updating component standards can lead to more energy-efficient vehicles. Sharif Qamar, associate director of transport and urban mobility at The Energy and Resources Institute (TERI), said, “After nearly five decades, piston ring standards for internal combustion engines have been upgraded from the old standards. The new framework reflects advances in materials, manufacturing, and performance requirements, ensuring better performance, durability, and compliance with current regulations.” The move also aligns with contemporary requirements in auto engine design, he added.
Many automakers one step ahead
Automobile sector experts said many automakers may have already adopted similar global standards, meaning the new BIS specification may not require significant technological adjustments from them. Ashim Sharma, senior partner and group head at Nomura Research Institute Consulting and Solutions, said, “There may be some automakers that have already adopted global standards, since the new Indian standards refer to changes in materials and coatings, among other requirements. Commonly, such upgrades in standards are made to incorporate technology changes.”
Mint reported in July 2025 that the union heavy industries ministry was also working on a scheme to increase auto parts exports by providing capex, opex, and intellectual-property-related support to the industry.
The revised norms come at a time when India is seeing rapid electric vehicle (EV) adoption even as ICE vehicles continue to dominate the domestic market. EVs accounted for around 8% of total new vehicle registrations in 2025, with sales of about 2.3 million units, largely two- and three-wheelers. Electric passenger vehicles made up roughly 5% of new car sales, while petrol and diesel vehicles accounted for the overwhelming majority of overall vehicle sales.
India is also working on tightening its car energy efficiency norms. The third iteration of the Corporate Average Fuel Efficiency (Cafe 3) norms is imminent, and will be enforced in April 2027. These norms nudge automakers to upgrade their technology and improve vehicle efficiency.