BENGALURU, November 7, 2026 — A dispute over the ethanol content of petrol has widened after Karnataka said laboratory tests on samples collected from seven districts found levels above the 20 per cent blend associated with E20 fuel. The state cited a highest reading of 31.2 per cent in one sample and publicly released 14 readings from the 63 samples it collected. Eleven of those 14 published readings were above 20 per cent; three were below it. Indian Oil Corporation, Bharat Petroleum Corporation and Hindustan Petroleum have rejected the allegation, arguing that the state’s results were not produced through the prescribed statutory and technical testing process. The companies say a separate exercise covering 893 samples across 27 States and Union Territories found all tested fuel within a 19–21 per cent range, including 56 samples from Karnataka.
The competing claims leave motorists with a real question but not yet a settled answer: whether any retail outlets supplied petrol outside the applicable specification, and whether the difference can be established through a jointly observed, repeatable test. The state’s figures are allegations based on its laboratory exercise; the oil companies’ figures are also claims based on their own quality-control exercise. Neither set of numbers should be treated as a final nationwide finding. The immediate issue is the quality-control process, the disclosure of test records and the ability of consumers to obtain a clear explanation from the authorities.
Food, Civil Supplies and Consumer Affairs Minister Rizwan Arshad said the department collected 63 samples from petrol stations in Bengaluru Urban, Bengaluru Rural, Kolar, Chikkaballapura, Ramanagara, Mangaluru and Tumakuru. The state said the samples were first sent to oil-company laboratories and that the information returned did not provide the ethanol-content detail it had requested. It then arranged further testing at laboratories described by the state as accredited. The figures released publicly included 31.2 per cent for an Indian Oil sample, 30.5 per cent for a Hindustan Petroleum sample, 26.5 per cent for a Bharat Petroleum sample, 26.1 per cent for a Nayara sample and 25.5 per cent for a Shell sample.
Among the 14 readings made public, three were below 20 per cent: 19.9 per cent for one BPCL sample, 19.2 per cent for a Mangalore Refinery and Petrochemicals Limited sample and 13.5 per cent for a Shell sample. That spread matters. It means the public allegation is not simply that every pump in Karnataka was selling fuel with an excessive blend. It is a claim about particular samples collected at particular outlets and tested under a procedure that the oil companies have challenged. A complete assessment requires the outlet identifiers, collection dates, seals, chain-of-custody records, laboratory certificates and the exact test method used for every sample.
The state has asked the Union government to examine the results and has called for action against companies if violations are established. It has also raised the question of compensation for vehicle owners who can demonstrate damage or additional costs caused by non-compliant fuel. Those demands are political and administrative requests at this stage, not an announced compensation entitlement. Motorists should not assume that a claim of over-blending automatically proves that a particular vehicle has suffered damage or that a payment scheme has been approved.
The three public-sector oil marketing companies issued a joint response saying the Karnataka claims were not supported by testing carried out in accordance with the relevant statutory and technical procedures. They said their quality exercise involved 893 samples from depots and retail outlets across 27 States and Union Territories. According to the companies, all 893 samples were within the 19–21 per cent range, while the 56 samples from Karnataka recorded between 19 and 20 per cent, with an average of 19.30 per cent.
The companies have questioned how the state samples were collected, handled and tested. Their response refers to the Motor Spirit and High Speed Diesel Regulation of Supply, Distribution and Prevention of Malpractices Order, 2005, and the Marketing Discipline Guidelines, 2024. The prescribed procedure is intended to preserve evidence and give the dealer, the oil company and the testing authority a documented share of the sample. The companies have said the certificates disclosed publicly did not identify enough technical detail about the test method, dilution procedure or reference material used to correct the readings. These objections do not prove that the state’s results are wrong, but they explain why the dispute cannot be settled by comparing two headline percentages.
A fair resolution would require both sides to disclose the records and agree on a repeat test at a mutually accepted laboratory. The exercise should specify the pump, product grade, date and time of collection, sampling container, seal numbers, storage conditions, test method and measurement uncertainty. If the results differ, an independent technical review should establish whether the difference arose from sampling, handling, laboratory method or the fuel itself. Without those safeguards, the public is left with competing claims rather than a result that can withstand scrutiny.
E20 is petrol blended with ethanol at a nominal proportion of 20 per cent by volume. Ethanol is an alcohol produced from biological feedstocks such as sugarcane, maize and other crops. India’s blending programme is intended to reduce dependence on imported crude oil, diversify fuel supply and create a market for domestic ethanol producers. The Ministry of Petroleum and Natural Gas has reported an average blending level of 20 per cent for the November 2025–June 2026 Ethanol Supply Year. That programme-level figure is not a certificate for every batch or every retail outlet; fuel quality still has to be controlled through specifications, supply-chain checks and retail inspections.
The relevant Indian Standard for E20 motor gasoline is IS 17021. It sets technical requirements for the fuel, including properties that matter to engine operation and storage. The public dispute has focused on ethanol percentage, but a complete fuel-quality assessment is broader than one number. Gasoline must also meet requirements for volatility, distillation characteristics, acidity, water content, appearance and other parameters. A laboratory result on ethanol content is important, but it should be interpreted alongside the full certificate and the standard’s prescribed test method.
The term “E20” is a product specification, not a guarantee that every vehicle on Indian roads is designed for every ethanol blend. Automakers have issued compatibility guidance for different model years and engine systems. Owners should use the fuel grade recommended in the vehicle handbook and check manufacturer guidance for their specific model. A general statement that all older vehicles will fail, or that every E20 vehicle will be damaged by a disputed sample, would go beyond the evidence available in this case.
Higher-than-specified ethanol content could matter because ethanol has different energy content and material-compatibility characteristics from petrol. If a fuel batch falls outside the required specification, the consequences may depend on the engine design, fuel-system materials, calibration, storage conditions and the extent of the deviation. A vehicle’s mileage can also change for reasons unrelated to fuel composition, including traffic, tyre pressure, driving style, load, maintenance and weather. A driver who notices lower mileage after refuelling should not assume that ethanol content is the cause without evidence.
For vehicles designed and approved for E20, the existence of a disputed laboratory result does not establish that the entire fuel programme is unsafe. For older vehicles, the practical advice is to consult the manufacturer rather than rely on social-media claims. If a vehicle develops unusual knocking, starting trouble, warning lights or a sudden performance change after refuelling, the owner should record the date, outlet, pump number, fuel grade and bill, then contact the vehicle maker and the fuel retailer. A service inspection can help establish whether the problem is connected to fuel, maintenance or another fault.
Motorists should keep the original fuel receipt where possible. It provides a time and location record that may help an oil company investigate a complaint. A consumer should describe the symptoms and request a written complaint number rather than making an unsupported accusation at the pump. Do not attempt to test petrol with household chemicals, store a sample in an unsafe container or drain fuel without professional assistance. Petrol is highly flammable, and informal sampling can destroy evidence or create a serious safety risk.
Retail outlets and oil companies also have a responsibility to explain their quality-control process. If a complaint is raised, the response should identify the relevant inspection procedure and the channel for escalation. State enforcement authorities can inspect retail outlets and collect samples under the applicable rules. The Centre can clarify the national specification and the procedure used to reconcile state and company results. A transparent, jointly witnessed testing programme would be more useful than another exchange of accusations.
The next meaningful development should be the release of complete test records and a decision on whether the samples will be retested through a jointly agreed process. Karnataka has said it wants the matter examined by the Union government. The oil companies have asked for the state’s records and have offered their own results as evidence of compliance. The Ministry of Petroleum and Natural Gas will need to clarify the applicable specification and the process for resolving a dispute between a state inspection and the companies’ quality-control exercise.
Until that happens, the most accurate description is that Karnataka has alleged excessive ethanol in some samples and the oil companies have disputed the testing method while presenting a separate set of results. There is no verified basis for saying that all E20 petrol across India contains more than 20 per cent ethanol, and no final finding has established that every sample identified by the state was non-compliant. The issue deserves independent testing, clear documentation and a public explanation because fuel quality affects household transport costs as well as confidence in a national energy policy.