The government has not estimated how many vehicles in India are fully compatible with E20 fuel, Parliament was informed on Monday. It, however, maintained that the ethanol blending programme is backed by scientific studies and consultations with automobile manufacturers and technical institutions.Responding to a query, minister of state for petroleum and natural gas Suresh Gopi said that no assessment to determine how many vehicles in the country are fully compatible with E20 fuel was carried out, while maintaining that studies and industry data have found the ethanol-blended fuel to be safe for use.“Ministry of Heavy Industries (MHI) have informed that no such assessment has been done by them,” the minister replied.While no estimate is available on the number of E20-compatible vehicles, said that the Ethanol Blended Petrol (EBP) Programme has been introduced through a phased, scientifically validated and consultative process. It said the programme involved NITI Aayog, automobile manufacturers, Oil Marketing Companies (OMCs), the Automotive Research Association of India (ARAI), the Society of Indian Automobile Manufacturers (SIAM), the Indian Institute of Petroleum (IIP) and other technical institutions.According to the reply, laboratory studies and field trials carried out by ARAI, SIAM, IOCL, IIP and vehicle manufacturers assessed engine durability, drivability, startability, corrosion resistance, material compatibility, emissions and fuel efficiency. These studies confirmed that E20 fuel is safe for use under prescribed standards.The government also said the studies established that legacy vehicles did not show any significant variation in performance or abnormal wear and tear when operated on E20 fuel.The reply said E15+ petrol has been in widespread use for more than three-and-a-half years, while E19-E20 fuel has been used for over two-and-a-half years. During this period, more than 20 crore two-wheelers and over 3 crore petrol cars have operated on these fuel blends without any verified evidence of widespread engine failure or vehicle breakdown attributable to ethanol blending.It also cited manufacturer service data, saying there has been no abnormal corrosion, wear or reduction in vehicle life linked to E20 fuel. Vehicle manufacturers, the government added, continue to honour warranty obligations for vehicles using the fuel.On fuel efficiency, the government said vehicles originally designed for E10 petrol may witness a mileage reduction of around 3-5 per cent. However, it added that E20 offers a higher octane rating, cleaner combustion, improved acceleration and lower emissions.As part of the data placed before Parliament, the government said one leading automobile manufacturer serviced 2.84 crore vehicles during FY 2025-26, including nearly 1.5 crore that were not originally certified as E20-compatible, and reported no E20-linked corrosion, abnormal wear or reduction in component life. Another manufacturer tracked 1.4 crore vehicles using E20 over an extended period and similarly found no evidence of ethanol-induced corrosion.