New Delhi, Feb. 26 -- Starting 1 April, petrol sold across Indian states and Union Territories must contain up to 20% ethanol and maintain a minimum Research Octane Number (RON) of 95. While the administration retains the authority to grant regional or time-bound exemptions under special circumstances, this directive signals a nationwide shift toward greener fuels.

The oil ministry, in a 17 February notification, said: "The central government hereby directs that oil companies shall sell ethanol-blended motor spirit (petrol) with percentage of ethanol up to 20% as per the Bureau of Indian Standards specifications and having minimum Research Octane Number (RON) of 95, in states and the Union Territories."

Ethanol, a renewable energy sourc...