New Delhi: The government on Wednesday said some rubber parts and gaskets in BS-III vehicles, introduced from April 1, 2005, and manufactured before 2016, may need to be replaced when operated with E20 fuel (petrol containing 20 per cent ethanol).
In a written reply to the Rajya Sabha, Road Transport and Highways Minister Nitin Gadkari said that with regard to the concern of vehicle mileage due to the use of E20 fuel, automobile manufacturers and vehicle/engine testing agencies have clarified that vehicle mileage is influenced by a host of factors beyond just fuel type.
Gadkari said a study for the evaluation of effects of E20 on two-wheelers and four-wheelers was carried out jointly by Indian Oil Corporation Limited (IOCL), Indian Institute of Petroleum (IIP) Dehradun, Society of Indian Automobile Manufacturers (SIAM) and Automotive Research Association of India (ARAI).
He said studies have not shown any need to modify the car and two-wheeler engines.
According to him, these studies confirmed that even legacy vehicles did not exhibit any significant variations in performance, nor do they show abnormal wear-and-tear when operated with E20 fuel.
The minister said no issues were reported in parameters such as drivability, startability, metal compatibility, and plastic compatibility.
“Only in case of testing done on BS-III vehicles introduced from 1st April, 2005, and manufactured prior to 2016, some rubber parts and gaskets may require replacement, which can be easily managed during routine servicing regime of the vehicle,” he said.
The rollout of E20 petrol (80 per cent petrol, 20 per cent ethanol) has drawn criticism from opposition parties and some consumer groups, who have raised concerns about its impact on older vehicles not specifically designed for 20 per cent ethanol blends.
Critics have 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 has been phased and backed by extensive testing, while automobile manufacturers have said they continue to honour warranty claims for vehicles using E20 fuel. Opposition parties have repeatedly sought greater transparency on vehicle compatibility and consumer safeguards.
The minister explained that an Inter-Ministerial Committee (IMC), constituted on December 26, 2020, under the Niti Aayog, comprehensively examined vehicle compatibility and mileage/efficiency aspects of ethanol blending. This assessment was supported by research conducted by Indian Oil Corporation Ltd (IOCL), Automotive Research Association of India (ARAI), and Society of Indian Automobile Manufacturers (SIAM).
The committee’s “Roadmap for Ethanol Blending in India 2020-25”, released in June 2021, was prepared after extensive consultation with automobile manufacturers, oil companies and agricultural experts, and examined material compatibility, engine calibration, fuel systems, drivability, durability, emissions and fuel efficiency.
The committee’s report preceded the introduction of E-20 fuel.
The Ethanol Blended Petrol (EBP) Programme has been implemented through a phased, calibrated, scientifically validated and consultative approach.
It has been used globally for over a century, with countries such as Brazil operating higher ethanol blends for decades.
In India, the Ethanol Blended Petrol (EBP) Programme commenced with a pilot in 2001, and E5 was introduced in 2006. Although blending remained around 1.53 per cent till 2013-14, it has since been increased progressively in a calibrated manner after creating the necessary production capacity, infrastructure and regulatory framework.
Before the introduction of E20 in April 2026, extensive laboratory studies, durability trials, and field validation were undertaken covering engine durability, material compatibility, fuel systems, corrosion resistance, drivability, emissions, fuel economy and overall vehicle performance.
BS, or Bharat Stage, refers to India’s vehicle emission standards that set limits on pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC) and particulate matter (PM).
