Guwahati: As the Union government pushes ahead with its ethanol-blending programme to cut emissions and reduce crude oil imports, a group of engineers has urged for more research and public awareness on its long-term impact, particularly on vehicle performance and personal savings.
The forum of Assam Engineering College graduates raised concerns after the Centre set a target of 30% ethanol blending in petrol by 2030, with 20% blending (E20) already being rolled out nationwide.
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India introduced ethanol blending in 2000 with E5, which later increased to E10 by 2022. The country achieved E20 in 2025, five years ahead of schedule, as part of Prime Minister Narendra Modi’s mission to cut greenhouse gas emissions and boost energy security.
Ethanol, a renewable and cleaner-burning biofuel, is produced from crops like sugarcane, maize, rice, and other agricultural biomass.
The petroleum ministry claims ethanol blending saved India over Rs 1 lakh crore in foreign exchange between 2014 and 2024, with additional savings of Rs 43,000 crore expected this year alone. Farmers have also benefited, earning over Rs 1.2 lakh crore through ethanol-linked crop procurement since 2014–15. India now ranks as the world’s fourth-largest ethanol producer.
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While supporting the government’s push for cleaner fuel, the engineers cautioned that ethanol has lower energy density than petrol, leading to a marginal drop in mileage — estimated at 1–2% in vehicles designed for E20, and 3–6% in older models. The petroleum ministry maintains that efficiency losses are minor and can be minimized through improved engine tuning, with leading carmakers already manufacturing E20-compatible vehicles.
However, the forum argued that many older vehicles, designed for E5 or E10, may face wear and tear if run on E20 without modifications. They suggested one-time repairs to parts such as fuel tanks, carburetors, and gaskets to adapt to higher ethanol blends.
The engineers also questioned whether ethanol-free or lower-blend petrol (E5 or E10) would remain available at India’s 90,000 fuel stations, giving older vehicle owners a choice.
They called for a nationwide study to evaluate the long-term effects of E20 on vehicles not originally designed for higher ethanol intake, stressing the need for a clear strategy to balance environmental goals with consumer interests.