The Centre has made the sale of E20 petrol compulsory across India from April 1, directing oil marketing companies to supply only fuel blended with 20 percent ethanol. The Petroleum Ministry has issued a formal notification stating that all states and Union Territories must ensure the availability of E20 petrol at fuel stations. While several regions had already introduced E20 fuel in 2023 on an optional basis, the new order makes it mandatory nationwide. The government had recently advanced its ethanol blending target from 2030 to 2025-26, and the full rollout now puts that plan into action.

Fuel specifications and octane requirement

Under the new norms, only E20 petrol with a minimum Research Octane Number of 95 can be sold. The RON standard has been fixed to protect engines from damage and prevent knocking, which refers to premature ignition inside the engine. RON measures a fuel’s ability to withstand pressure before igniting. The higher the RON value, the better the fuel performs under compression without causing noise or vibration. A higher rating also supports smoother functioning and enhances engine life. So far, regular petrol sold in India carries 91 RON, while premium variants such as XP95 offer 95 RON.

Impact on vehicles and mileage concerns

Industry experts say most vehicles manufactured between 2023 and 2025 are designed to run on E20 fuel and are unlikely to face issues. However, older vehicles could experience certain challenges. The possible impact includes:

• Mileage drop: Fuel efficiency in older vehicles may decline by 3 to 7 percent.
• Component wear: Prolonged use may affect rubber and plastic parts in ageing engines.

Officials have clarified that in exceptional circumstances, limited and temporary exemptions may be granted in specific areas. However, the rule will largely apply to all fuel stations across the country.

Foreign exchange savings and farm boost

The government has cited reduced dependence on crude oil imports as the primary reason behind the decision. According to estimates by the Oil Ministry, ethanol blending in petrol since 2014-15 has helped India save over Rs 1.40 lakh crore in foreign exchange. Ethanol is produced from sugarcane, maize and other grains, providing an additional income stream for farmers. The blending programme is therefore being positioned as both an energy security measure and an agricultural support initiative.

What ethanol is and how it is made

Ethanol is a type of alcohol produced through the fermentation of starch and sugar. It is mixed with petrol and used as a relatively eco-friendly automotive fuel. In India, ethanol production mainly relies on sugarcane juice, but it can also be derived from maize, rotten potatoes, cassava and other starch-containing materials.

There are different generations of ethanol and biofuels:

• 1G ethanol: Produced from sugarcane juice, sweet sorghum, maize, sugar beet and rotten potatoes.
• 2G ethanol: Derived from cellulose and lignocellulosic materials such as rice husk, wheat straw, corn cobs, bamboo and woody biomass.
• 3G biofuel: Planned to be developed from algae; research is currently underway.

Blending journey and future roadmap

India began ethanol blending with a 5 percent mix, gradually raising it to 20 percent. E20 petrol has been sold in the country since April 2023, but its supply was not compulsory until now. Governments worldwide are exploring ethanol-blended fuels to curb vehicular air pollution and moderate fuel prices, and India sees ethanol as an alternative to conventional petrol and diesel.

The government has also initiated steps under the National Bio Fuel Policy to eventually move from E20 to E80, which would contain 80 percent ethanol and 20 percent petrol. From April onward, only flex-fuel compliant vehicles are being sold in the country. Older vehicles, officials say, can be converted into ethanol-compliant models, marking a broader transition in India’s fuel ecosystem.