Karnataka has collected and tested petrol samples from 67 locations across the state after thousands of motorists complained that excessive ethanol blending was damaging their vehicles and cutting fuel efficiency, Chief Minister D.K. Shivakumar said on Sunday.
The state government has taken the complaints seriously and will release a detailed inspection report on Monday, when Food and Civil Supplies Minister Rizwan Arshad is scheduled to hold a press conference setting out the findings and the next course of action.
Shivakumar said the government had taken serious note of complaints that ethanol content in petrol had crossed the prescribed 20 per cent limit under the Centre's E20 programme. In some samples, the ethanol content was reported to be as high as 31.5 per cent, far above the mandated level. The Chief Minister said the investigation had already established that the problem was real and widespread, and he placed the responsibility for resolving it squarely on the Centre.
"Thousands of motorists have complained about various issues, including reduced vehicle mileage and unexpected stalling of engines," Shivakumar told reporters in Bengaluru. He said vehicles were failing to cover the expected distance on a full tank, engines were switching off while in motion, and fuel efficiency had dropped sharply.
"In light of complaints that engine performance in vehicles is being adversely affected due to the increased proportion of ethanol in vehicle fuel, petrol samples were collected and tested at 67 locations across the state," he said.
The Chief Minister said about 30 per cent of the investigation had been completed so far, and the state government had already informed the Centre about all 67 locations from which samples were drawn. He said the findings would be made public and the government would not allow the matter to be covered up. "We have conducted an investigation first. Tomorrow, our minister will officially hold a press conference and give all details. The government cannot cover it up," Shivakumar said.
The row began earlier when Rizwan Arshad released details of an inspection carried out by the Food, Civil Supplies and Legal Metrology Department. According to Arshad, laboratory tests on petrol samples collected from seven districts had found ethanol content significantly above the prescribed E20 limit.
The samples covered outlets operated by Indian Oil Corporation, Bharat Petroleum and Hindustan Petroleum, as well as private retailers, in Bengaluru, Kolar, Chikkaballapura, Ramanagara, Mangaluru and Tumakuru.
Arshad said tests on 63 samples from the seven districts had recorded ethanol concentrations as high as 31.2 per cent, with 11 of 14 samples reportedly exceeding the prescribed 20 per cent limit. In one Indian Oil sample, the ethanol content was measured at 31.2 per cent, while a Hindustan Petroleum sample showed 30.5 per cent. According to the minister, most of the tested samples allegedly exceeded the 20 per cent threshold.
The samples were tested at laboratories accredited by the National Accreditation Board for Testing and Calibration Laboratories.
The three state-run oil marketing companies rejected the findings in a joint statement on Friday. Indian Oil Corporation, Bharat Petroleum Corporation and Hindustan Petroleum Corporation maintained that the petrol supplied by them across the country, including in Karnataka, complied with the Bureau of Indian Standards specification for E20 fuel.
They questioned the sampling procedure and testing methodology used in the state government's October 2026 exercise, arguing that the findings were based on third-party laboratory certificates that did not follow the prescribed statutory and technical procedures.
The companies also disputed the state's claim that petrol sold at some retail outlets contained between 26 and 31 per cent ethanol, saying the results could not be independently verified. The disagreement has now turned into a full-blown political confrontation between the Congress government in Karnataka and the Centre, with Shivakumar accusing the Union government of failing to act on a problem that affects millions of vehicle owners.
Shivakumar alleged that cheaper ethanol was being mixed with petrol in larger quantities to increase profits, and claimed that the excessive blending was taking place at petrol pumps during distribution rather than only at the supply stage. He said the government possessed documentary evidence to support its findings. "The Centre cannot shirk responsibility on this matter. Vehicle performance, fuel quality and public safety are paramount," he said.
The Chief Minister said the investigation had expanded beyond retail outlets to cover the stages where ethanol is blended and distributed. Officials have collected samples, records and documents from multiple stages of the fuel supply chain as part of the ongoing probe. Inspections were held not only at petrol pumps but also at the points where ethanol is blended and distributed, and documents detailing where and how the blending is done have been collected, he said.
The controversy has also spread beyond Karnataka. Kerala has ordered its own laboratory testing of petrol samples after the Karnataka findings, with the state's Food and Civil Supplies Department directing checks in several districts. Union Minister of State for Petroleum and Natural Gas Suresh Gopi said the Karnataka and Kerala governments were free to conduct their own tests on fuel quality.
The Petroleum Ministry has defended the ethanol blending programme, stating that all 893 E20 petrol samples tested across 27 states and Union Territories complied with prescribed quality standards. The ministry's statement stands in direct contrast to Karnataka's findings, and the dispute now turns on whose testing process is accepted as reliable. The oil companies have sought joint and transparent testing to settle the question.
The E20 programme requires petrol sold in India to contain 20 per cent ethanol, a biofuel largely produced from sugarcane and other feedstocks. The programme is intended to reduce the country's dependence on imported crude oil, cut carbon emissions and support farm incomes. The government has pushed the blending target aggressively in recent years, and E20 fuel is now sold widely across the country.
Motorists' complaints in Karnataka, however, have raised questions about whether the blending is being carried out within the prescribed limits at every stage of the supply chain.
For vehicle owners, the stakes are practical and immediate. Higher ethanol content can affect older vehicles in particular, because ethanol absorbs water, can corrode certain fuel system components and delivers less energy per litre than petrol, which reduces mileage.
Mechanics and motorists in Karnataka have reported a pattern of complaints that matches the state's findings: vehicles that stall without warning, engines that lose power, and fuel tanks that empty far sooner than expected. The state government says thousands of such complaints have reached it from across Karnataka.
What happens next will depend on the report that Rizwan Arshad presents on Monday. The minister is expected to release the full inspection findings, name the locations and outlets where samples were taken, and announce what action the government proposes to take. The report is likely to intensify the political dispute, since the Centre and the oil companies have already rejected the state's testing methods.
If the state stands by its findings, it could press for enforcement action against outlets found to be selling over-blended fuel, and for a re-examination of how blending is monitored nationally.
The episode has also sharpened the debate over who should police fuel quality in India. At present, the oil marketing companies test their own fuel and certify compliance with Bureau of Indian Standards specifications, while state food and civil supplies departments have powers to check weights, measures and adulteration at retail outlets.
Karnataka's exercise shows what happens when the two systems produce different answers, and the row is likely to prompt calls for independent, jointly supervised testing that both sides can accept.
For now, motorists in Karnataka are waiting for Monday's report to learn how widespread the problem is and what the government intends to do about it. The Chief Minister has promised full disclosure, and the oil companies have promised to cooperate with transparent testing. Until the two sides agree on the facts, the argument over what is actually in Karnataka's petrol will continue, with the state's 67 tested locations at the centre of the dispute.
(Reporting based on The Hindu and The Indian Express.)