Starting April 1, 2026, petrol stations across India will supply ethanol-blended petrol with up to 20% ethanol. The petrol will also have a minimum Research Octane Number (RON) of 95. This shift marks a significant step in India’s ethanol-blending roadmap.
Understanding RON 95
RON, or Research Octane Number, measures a fuel’s resistance to engine knocking. Knocking occurs when the fuel-air mixture ignites unevenly in the engine, reducing efficiency and causing long-term engine damage. The higher the RON, the better the fuel can withstand compression before igniting.
Higher RON = better resistance to knocking and improved performance, especially for high-compression or turbocharged engines. A RON 95 rating ensures that fuel performance and combustion stability remain intact, even with the higher ethanol content.
Why 20% Ethanol?
Ethanol is a renewable fuel made from agricultural products like sugarcane and maize. Increasing ethanol content to 20% aims to:
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Reduce crude oil imports
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Lower tailpipe emissions
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Support farmers and ethanol producers
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Enhance energy security
This fuel will comply with standards set by the Bureau of Indian Standards (BIS), ensuring quality consistency across states.
What E20 with RON 95 Means for Your Car
For E20-Compatible Vehicles
Most new vehicles and two-wheelers launched in India since 2023 are designed to handle E20 fuel. These vehicles have:
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Fuel lines, seals, and injectors that resist ethanol’s corrosive properties
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ECU mapping adjusted for ethanol-blended fuel
While performance remains stable, a slight decrease in fuel efficiency might occur. Ethanol has a lower energy density than pure petrol. However, the higher RON 95 rating may benefit turbocharged engines by improving combustion and consistency.
For Non-E20-Compatible Vehicles (Older Cars)
For older cars that are not compatible with E20, several issues may arise:
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Material compatibility: Ethanol is more corrosive than petrol and may degrade older fuel hoses, seals, and metal parts.
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Fuel efficiency: Ethanol contains less energy per litre than petrol, leading to reduced mileage and potential cold-start problems.
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Long-term wear: Continuous use of E20 in non-compatible engines may cause wear in fuel pumps and injectors.
Owners of older cars, especially pre-2020 models, should:
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Check their car’s owner manual for E20 compatibility
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Consult authorized service centers for guidance
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Perform preventive maintenance on fuel system components
Looking Ahead
India’s push for ethanol-blended fuel is part of a broader strategy to reduce oil imports and promote cleaner energy. Although new cars are prepared for E20, older vehicles may face some challenges. Awareness and proactive maintenance will help mitigate these issues.
April 1, 2026 marks a significant shift, but it won’t change your refueling habits overnight. However, it signals an important change in fuel requirements for your vehicle moving forward.
