Overview

• Government files obtained via RTI show the first 5% ethanol blend mandate was issued in 2002 under Atal Bihari Vajpayee after 2001 pilots in Maharashtra and Uttar Pradesh.
• Subsequent UPA notifications extended blending across more states and, in 2013, directed oil companies to retail petrol with up to 10% ethanol, setting a national policy framework that the Modi government later accelerated.
• Recent orders under the current government mandated E10 nationwide from 2019, legally codified E100 in 2021, authorised E20 the same year, and set the path that has led to broad E20 availability since April 2025, with norms for E27 reported as expected soon.
• Guwahati workshops and motorists report lower mileage and mechanical issues, particularly in older vehicles, while pump‑level labelling remains limited according to consumer reports.
• The Supreme Court dismissed a petition seeking ethanol‑free options and mandatory labelling, as Transport Minister Nitin Gadkari defends the programme’s safety even as automakers caution many legacy models may require recalibration or could face corrosion risks.