The sale of ethanol blended petrol has been made compulsory effective April 1, 2026. The government has made it mandatory to market petrol blended with ethanol at levels of up to 20% and with a minimum Research Octane Number (RON) of 95. This mandate is applicable across all states and Union Territories of India.In a notification issued on February 17, the oil ministry has said that oil marketing companies must supply ethanol-mixed motor spirit (petrol) containing ethanol up to 20%, in accordance with specifications set by the Bureau of Indian Standards, and meeting the requirement of a minimum RON of 95 across the country.The Centre may, however, permit exemptions under exceptional circumstances for certain areas and for limited durations, a PTI report said.After India achieved 10 per cent ethanol blending in petrol in June 2022 – five months ahead of schedule — the government brought forward the target for 20% blending to 2025-26 instead of 2030. At present, most fuel stations across the country supply E20 petrol, which contains 20% ethanol.The oil ministry estimates that since 2014-15, replacing a portion of petrol with ethanol has resulted in foreign exchange savings of over Rs 1.40 lakh crore.
What is ethanol-blended E20 petrol?
- Fundamentally, E20 petrol has 20% ethanol and 80% petrol.
- The requirement to blend ethanol with petrol has been introduced to lower dependence on imported crude oil and curb emissions.
- The policy is also intended to benefit farmers by increasing demand for crops such as sugarcane and maize as well as surplus agricultural produce.
- Ethanol is produced from sources such as sugarcane, maize and other grains. It is a renewable fuel, manufactured domestically, and burns more cleanly compared to conventional petrol.
- The requirement for a minimum Research Octane Number (RON) of 95 has been introduced to safeguard engines from potential damage.
- RON indicates a fuel’s ability to resist knocking, or premature ignition inside the engine. Knocking occurs when fuel combusts irregularly, leading to a pinging noise, reduced engine performance and, over time, possible mechanical damage.
- A higher RON rating means the fuel is better able to withstand knocking. In simple terms, octane reflects how stable a fuel remains under pressure – the higher the RON, the greater its stability during high compression.
- Ethanol naturally has a high octane rating of roughly 108 RON. Mixing petrol with 20% ethanol improves resistance to knocking.
Concerns about mileage & what government has said
Industry officials said that the majority of vehicles produced in India between 2023 and 2025 are engineered to operate on E20 fuel, and significant technical problems are not anticipated.However, older vehicles could experience a modest decline in fuel efficiency of around 3-7%. There may also be some deterioration in rubber and plastic components over time.Last year, the Ministry of Petroleum & Natural Gas moved to dismiss concerns of damage to vehicles due to E20 petrol.A life-cycle emissions assessment conducted by NITI Aayog found that ethanol derived from sugarcane and maize results in greenhouse gas emissions that are approximately 65% and 50% lower, respectively, than those associated with petrol.Issues relating to vehicle performance and fuel efficiency had already been anticipated by the government as early as 2020, and these concerns were examined in detail by an inter-ministerial committee of NITI Aayog. The evaluation was supported by technical studies conducted by IOCL, ARAI and SIAM.Use of E20 fuel has been found to provide improved acceleration and smoother driving performance, while also reducing carbon emissions by roughly 30 per cent compared with E10 fuel, the government said. Ethanol’s naturally higher octane rating — about 108.5 compared with petrol’s 84.4 — makes ethanol-blended fuels particularly suitable for engines requiring higher octane levels, especially modern high-compression engines. Vehicles calibrated for E20 fuel tend to offer better acceleration, which is especially beneficial under urban driving conditions. In addition, ethanol’s higher heat of vaporisation lowers temperatures in the intake manifold, increasing the density of the air-fuel mixture and enhancing volumetric efficiency, the government had said.
