NEW DELHI: Both the automobile industry and the government have admitted that E20 ethanol-blended petrol reduces vehicle mileage by 2%–6%, leaving consumers with the double burden of paying higher fuel prices while getting fewer kilometres out of their tanks.
Take the case of Surender Pal Singh, a Delhi-based automobile engineer. He said the mileage of his less than three-year-old car has dropped sharply in the past six months. “When I bought the car, it averaged 17–17.5 km per litre on Delhi roads. Last year, it slipped to 16.5 km, which I assumed was due to traffic or my driving style. But in the past few months, it has fallen to 14.5 km,” said Singh, who previously headed a major driving institute. Switching to premium fuel—around ₹7 costlier per litre—helped improve his mileage, he added.
Many motorists have shared similar experiences on social media, questioning why they must pay more for fuel that delivers less efficiency.
A 2021 NITI Aayog report on India’s ethanol-blending roadmap recommended that the retail price of higher ethanol blends should be kept lower than regular petrol to offset reduced calorific value and encourage adoption. It also suggested tax breaks on ethanol fuels. The report noted that E20 could lower efficiency by 6%–7% in four-wheelers designed for pure petrol (E0) and calibrated for E10, and by 3%–4% in two-wheelers. For vehicles designed for E10 and calibrated for E20, the drop was estimated at 1%–2%. Engine modifications, it added, could reduce this loss.
Meanwhile, the Automotive Research Association of India (ARAI), citing studies from 2016 and 2021, maintained that its tests found no adverse impact of E20 on vehicles.
