Government mandates minimum 95 octane rating for petrol from April

The Indian government has mandated the sale of petrol with an octane rating of at least 95 RON (Research Octane Number) from April 1, 2026. This will take effect exactly a year after the nationwide rollout of petrol with a 20 percent ethanol blend (E20). Interestingly, ethanol by itself has a high octane rating of around 108 RON. When blended with petrol at up to 20 percent, it helps increase the fuel’s overall octane level.

1. Regular petrol has an octane rating of around 91-92 RON
2. BIS norms to be standardised for ensuring consistency in fuel quality

As per oil companies, a 20 percent ethanol blend raises the octane rating by about 6 RON. So, if regular petrol earlier had an octane rating of around 91-92 RON, E20 fuel should now be closer to 97-98 RON.

Ethanol blending aimed at cutting imports

This move marks the next phase of India’s ethanol-blending programme aimed at reducing crude oil imports and lowering emissions. Ethanol, which is made from sugarcane, maize and other grains, is a domestic and renewable fuel. Increasing the blending ratio helps cut dependence on imported oil while also supporting farmers by boosting demand for agricultural feedstock. 

What’s also noteworthy is that the fuel will be standardised under Bureau of Indian Standards (BIS) norms to ensure consistency in fuel quality across India. This directly addresses one of the key concerns we had flagged regarding contamination of ethanol. Since ethanol is hygroscopic and can absorb moisture and impurities, poor blending practices can lead to issues, especially in fuel-injected engines.

With BIS specifications in place, stricter quality control at the blending and distribution stages should minimise the risk of contaminated ethanol entering the supply chain. Additionally, some brands have already begun offering E20 conversion kits for older vehicles to tackle compatibility concerns.