Amid growing complaints from vehicle owners about declining fuel efficiency, experts have warned that the use of 20 percent ethanol-blended petrol (E20) in India could lead to a mileage drop of 2–5 percent. According to automotive industry sources, the extent of the decline depends largely on the vehicle type. Older cars that are not E20 compliant may suffer long-term damage such as erosion of gaskets, fuel hoses, and rubber pipes, which could further impact efficiency. The drop, experts note, is mainly due to the lower calorific value of ethanol compared to petrol.
Government Defends E20 Fuel, Cites Marginal Mileage Impact and Engine Safety
The Indian government has promoted ethanol blending as a national initiative to reduce dependency on crude oil and promote cleaner fuels, using ethanol primarily derived from sugarcane or maize. The oil ministry earlier maintained that any efficiency loss in E10 vehicles is marginal and dismissed claims of a “drastic” reduction with E20 as misplaced. It also pointed out that some manufacturers have been producing E20-compatible vehicles since 2009, and in such cases, there should be no drop in mileage. In fact, E20-tuned vehicles can deliver better acceleration, a significant advantage in urban driving conditions.
Government data suggests that ethanol’s lower energy density results in a small decrease in mileage—1–2 percent for four-wheelers designed for E10 and recalibrated for E20, and about 3–6 percent for non-compliant vehicles. Another industry expert emphasized that E20-compatible vehicles face no engine damage since their components are designed to withstand ethanol use. However, for non-compliant cars, gradual wear and tear of internal parts could emerge over time, though not immediately.
Public Slams Overpricing of Ethanol-Blended Fuel
Despite these clarifications, the policy has faced public criticism. Social media users argue that while ethanol-blended petrol costs at least ₹9 less per liter to produce, consumers are not seeing the benefit, as they continue to be charged higher prices, effectively accusing the government of overpricing fuels.
Summary:
Experts warn that E20 petrol may reduce mileage by 2–5%, especially in older, non-compliant vehicles, due to ethanol’s lower calorific value. The government defends the policy, citing marginal impact and better acceleration in tuned cars. Public criticism persists, with accusations of overpricing despite ethanol-blended fuel being cheaper to produce.
