Policy Overview The central government has issued a notification directing all oil companies to sell petrol blended with up to ethanol blending of 20% (known as E20 ) and a minimum Research Octane Number (RON) of 95 across all States and Union Territories, effective 1 April 2026 . The specification follows the standards set by the Bureau of Indian Standards (BIS) . Key Developments Mandatory sale of E20 from 1 April 2026. Minimum RON 95 to safeguard engines against engine knocking . Exceptions may be granted for special regions or temporary situations. Most vehicles manufactured between 2023‑2025 are engineered for E20 , with no major performance issues expected. Older cars could see a marginal mileage drop of 3‑7% and possible wear of rubber/plastic components. Important Facts Ethanol is derived from sugarcane, maize or other grains , making it a renewable domestic fuel. Blending 20% ethanol raises the fuel’s octane rating (ethanol’s intrinsic RON ≈ 108), enhancing knock resistance. The policy aims to curb oil imports and reduce vehicular emissions, while creating a market for agricultural surplus. Since FY 2014‑15, India has accrued over ₹1.40 lakh crore in foreign exchange savings through petrol substitution. India achieved 10% ethanol blending in June 2022, five months ahead of schedule, prompting the accelerated target of 20% by 2025‑26 instead of 2030. UPSC Relevance The mandate touches upon multiple GS papers: GS III (Economy) – energy security, renewable fuel policy, balance of payments; GS II (Polity) – role of the Ministry of Petroleum & Natural Gas and regulatory framework; and GS I (Geography) – agricultural linkages and regional disparities. Understanding ethanol blending helps answer questions on sustainable energy, while the RON requirement illustrates technical standards influencing policy. Way Forward Monitor compliance by oil companies and address supply‑chain bottlenecks for ethanol feedstock. Strengthen infrastructure for ethanol production, especially in sugarcane‑rich states. Periodically review the impact on vehicle performance, consumer costs, and foreign exchange savings . Consider phased incentives for retrofitting older vehicles to mitigate mileage loss.