E20 petrol: Centre says 3-5% mileage drop possible, rejects engine damage claims

Amid a growing nationwide debate over E20 petrol, the Centre on Friday defended its ethanol-blending programme, assuring motorists that the fuel is safe for vehicles and does not cause engine damage or major performance issues.

The clarification comes after a wave of complaints from vehicle owners and viral social media posts claimed that petrol containing 20% ethanol could damage engines and rubber components, increase maintenance costs and reduce fuel efficiency, particularly in older vehicles that were not originally designed for lower ethanol blends.

Fuel Economy

E20 petrol, a blend of 20% ethanol and 80% petrol, is a key part of India's plan to reduce crude oil imports, cut carbon emissions and boost domestic ethanol production. The government said the transition was backed by extensive scientific testing and consultations with automobile manufacturers before the fuel was rolled out nationwide.

According to the government, India achieved its E10 blending target in June 2022, five months ahead of schedule under the Ethanol Supply Year (ESY) 2020-21 programme.

“For E20, an even more rigorous process was followed. Extensive consultations were held with automobile manufacturers, component suppliers, testing agencies and research institutions,” the official statement.

“Every aspect was examined, starting from material compatibility, engine calibration, fuel systems, drivability, durability, emissions and fuel efficiency,” it added.

Before introducing E20 petrol nationwide, multiple rounds of discussions were held with automobile companies, testing agencies, industry experts and other stakeholders to ensure that manufacturers and fuel supply systems were prepared for the transition, the government said.

Citing industry experience, the government pointed to data from major automobile manufacturers. Maruti Suzuki serviced around 2.84 crore vehicles during the financial year 2025-26, including nearly 1.5 crore older vehicles that were not E20-certified. The company reportedly found no cases of ethanol-related corrosion, unusual wear, or reduced component life. Similar feedback has also been reported by Hero MotoCorp, the government added.

Impact on mileage

The Centre said real-world performance data from millions of vehicles provides a more accurate assessment of E20’s impact compared with isolated individual complaints or online claims.

“It is true that in some vehicles there may be a 3-5% reduction in fuel economy. But mileage is only one parameter,” the government said.

“E20 offers a significantly higher-octane rating, superior anti-knock characteristics, faster combustion, better pickup, smoother acceleration and cleaner engine operation,” it said.

Environmental benefits

Highlighting environmental benefits, the government said ethanol-blended fuel produces negligible particulate emissions and can reduce lifecycle carbon emissions by nearly 40%. It described E20 as a cleaner, more efficient fuel than E10 petrol or pure gasoline.

The government also stressed that India has developed a large fuel distribution network to support the transition, with more than one lakh retail outlets connected through refineries, storage terminals, depots and pipeline infrastructure.

The E20 rollout is part of India’s broader renewable energy and energy security strategy, aimed at reducing crude oil imports while supporting farmers and the domestic biofuel industry.

“E20 represents cleaner combustion, lower emissions, reduced crude oil imports, higher incomes for Indian farmers and greater energy security for the nation”, the statement said.

“Once a superior fuel has been scientifically validated, extensively tested and accepted by the automotive industry, the objective should be to move forward with confidence, not to retreat to an inferior standard,” it added.