Starting April 1, every petrol pump across India will sell a new standard fuel. The Centre has made it mandatory for oil marketing companies to supply petrol blended with up to 20% ethanol, along with a minimum Research Octane Number (RON) of 95, across all states and Union Territories.
The move marks a major milestone in India’s long-running ethanol blending programme. While exemptions may be allowed in exceptional cases for specific regions and limited periods, the policy effectively makes E20 petrol the default fuel for the country.
Bigger policy push
India reached 10% ethanol blending in June 2022, five months ahead of schedule. Encouraged by the progress, the government advanced its 20% blending target from 2030 to the 2025-26 ethanol supply year.
The policy is driven by three strategic goals, that are cutting crude oil imports, reducing emissions and boosting farm incomes. Replacing a portion of petrol with ethanol since 2014-15 has helped save over Rs 1.40 lakh crore in foreign exchange, news agency PTI reported citing the oil ministry.
What exactly is E20 fuel?
Ethanol, produced from sugarcane, maize and other grains, is a domestically manufactured renewable fuel. By creating a stable demand for agricultural feedstock and surplus produce, the blending programme is also designed to strengthen the rural economy.
E20 petrol contains 20% ethanol and 80% conventional petrol. One key requirement under the new mandate is a minimum RON of 95.
RON measures a fuel’s resistance to knocking or premature combustion inside the engine. Knocking can reduce performance and over time, damage engine components. A higher RON means greater stability under high compression.
This is where ethanol helps. With a natural octane rating of around 108, ethanol improves the anti-knock quality of blended fuel. The higher RON specification is intended to ensure engine safety even as ethanol content rises.
In simple terms, the policy does two things at once — it increases renewable content while upgrading fuel quality.
What it means for vehicles
For most newer vehicles, the transition is unlikely to cause major issues. The PTI report quoted industry officials suggesting that the majority of vehicles manufactured between 2023 and 2025 are already calibrated to run on E20.
However, the older vehicles may see some impact. Experts indicate a possible drop in fuel efficiency of about 3-7% because ethanol has lower energy content than petrol. Over long periods, there could also be minor wear in certain rubber or plastic components not designed for higher ethanol concentrations.
The government has sought to address these concerns. Technical evaluations by agencies such as the Automotive Research Association of India (ARAI), Indian Oil Corporation (IOCL) and the Society of Indian Automobile Manufacturers (SIAM) found no major performance risks for compatible vehicles.
In fact, ethanol’s high octane value can improve combustion. Vehicles designed for E20 may experience smoother acceleration and better performance, especially in urban driving conditions.
Environmental gains
Beyond energy security, emissions reduction is a core objective. A life-cycle analysis by NITI Aayog found that ethanol from sugarcane and maize can cut greenhouse gas emissions by roughly 65% and 50%, respectively, compared with petrol.
The government also estimates that moving from E10 to E20 can reduce tailpipe carbon emissions by about 30%.
Another technical advantage is ethanol’s higher heat of vaporisation, which lowers intake temperatures in engines. This improves air-fuel mixture density and overall efficiency in high-compression modern engines.
An industry-wide shift
For oil companies, the mandate formalises a supply chain transformation already underway, from ethanol procurement to storage, blending and distribution. For automakers, it accelerates the shift toward E20-compatible engines as a standard requirement.
The April 2026 rollout also signals the government’s intent to use biofuels as a bridge strategy in the energy transition, alongside electric mobility and alternative fuels.