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

Research Octane Number (RON) is the standard measure of a gasoline's ability to resist engine knocking (pre-ignition/detonation) at low speeds and under light loads, simulating typical city driving. A higher RON indicates better stability and higher knock resistance, allowing for higher compression ratios in engines.