What E20 actually is, and how India got here

E20 is 20% ethanol blended with 80% petrol. Ethanol carries roughly 30% less energy per litre than petrol Advanced BioFuels USA. That single fact explains almost every mileage number on this site: a vehicle burning E20 needs more litres to travel the same distance than one burning pure petrol, unless the engine is specifically tuned to claw back the difference through a higher compression ratio and better combustion. The debate isn’t whether this happens — it’s how much, in which vehicles, and who absorbs the difference.

India’s Ethanol Blended Petrol Programme began in 2003, but progressed slowly — blending was still around 1.5% in 2014 Deccan Herald. The 2018 National Policy on Biofuels targeted 20% blending by 2030. That target was then advanced twice — first to 2025, then effectively delivered by 2025–26 — compressing what Brazil spent five decades building into roughly five years.

Before the rollout, a 2014–15 study by ARAI, the Indian Institute of Petroleum, and Indian Oil R&D found up to a 6% decline in fuel economy, varying by vehicle type. The 2021 NITI Aayog roadmap went further, estimating a 6–7% loss for older four-wheelers and 3–4% for two-wheelers not specifically calibrated for E20 — and recommended keeping lower-blend fuel available for those vehicles during the transition NITI Aayog Roadmap. That recommendation was not implemented as a consumer option — a decision explored further in Your Rights.