E20 petrol can reduce fuel economy by 2-6%, says Gadkari defending ethanol blending

Petrol blended with 20% ethanol, commonly known as E20, can reduce fuel economy by 2-6% depending on the vehicle category, informed Union Minister for Road Transport and Highways, Nitin Gadkari, in the Parliament. The minister, however, argued that tests for engine durability on a dynamometer and on-road vehicle tests have not shown any failures due to E20.

In a written reply to questions in the Lok Sabha, while defending the ethanol blending programme, Gadkari said E20 fuel provides better acceleration, improved ride quality and approximately 30% lower carbon emissions compared to E10 fuel. He also said that a study to evaluate the effect of E20 on BS-III, BS-IV and BS-VI E10 two-wheelers and four-wheelers was carried out jointly by ARAI, SIAM and Indian Oil Corporation Ltd (IOCL). The study claimed to comprise standard testing as per the respective certification requirements & customized test protocols developed along with the Original Equipment Manufacturers (OEMs).

The minister, in his response in Lok Sabha, accepted that the fuel efficiency of vehicles may be reduced by 2-6% depending on the vehicle category and vintage. However, he also stated that the tests for engine durability on a dynamometer and vehicle tests on the road have not shown any failures due to E20.

The rollout of E20 petrol, which is 80% petrol blended with 20% ethanol, has drawn sharp criticism from opposition parties and some consumer groups. Many motorists have raised concerns about the impact of E20 on older vehicles, which are not specifically designed for 20% ethanol blended petrol. Critics have also questioned whether all vehicles are fully compatible with E20, flagged the possibility of reduced fuel efficiency and higher maintenance costs, and sought clarity on liability if engine or fuel-system problems arise.

The government has maintained that the transition to E20 has been phased and backed by extensive testing. The automobile manufacturers have said they continue to honour warranty claims for vehicles using E20 fuel.

Responding to these concerns, Gadkari explained that the Ethanol Blended Petrol (EBP) programme has been implemented through a phased, scientifically validated and consultative process involving NITI Aayog, automobile manufacturers, Oil Marketing Companies (OMCs), Automotive Research Association of India (ARAI), Society of Indian Automobile Manufacturers (SIAM), Indian Institute of Petroleum (IIP) and other technical institutions. He noted that more than 20 crore two-wheelers and over three crore petrol cars have been operating on these blends without any verified evidence of widespread engine failure or vehicle breakdown attributable to ethanol blending. "Manufacturer service data confirm that there is no abnormal corrosion, wear or reduction in vehicle life due to E20 fuel," he said, adding that manufacturers continue to honour warranty obligations for vehicles using E20 fuel, providing further confidence in its safety and reliability.

Claims regarding E20 are misleading: Petroleum ministry

The Ministry of Petroleum and Natural Gas has refuted what it termed as ‘misleading claims’ regarding E20, asserting that there is no verified evidence of widespread engine damage linked to the fuel following years of scientific vetting and real-world usage across crores of vehicles. Addressing the concerns raised on social media platforms, the ministry clarified that its conclusions stem from over 25 years of phased implementation, continuous field tracking, and exhaustive stakeholder consultations.

In a detailed clarification, the ministry said its conclusion is based on over 25 years of phased implementation, extensive scientific validation, continuous field experience across crores of vehicles, manufacturer service records, stakeholder consultations, and ongoing quality monitoring. Responding to concerns over older vehicles, the ministry cited service data from a leading automobile manufacturer, which serviced 2.84 crore vehicles in FY2025-26, including around 1.5 crore vehicles that were not originally certified as E20-compatible, and found no E20-linked corrosion, abnormal wear or reduction in component life.

The ministry also addressed concerns over fuel economy, saying any reduction in mileage for some older E10-designed vehicles is generally limited to 3-5%, while factors such as driving habits, tyre pressure, traffic conditions and vehicle maintenance have a much greater impact. It added that E20 offers a higher octane rating, cleaner combustion and smoother engine performance.

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