India’s flagship ethanol programme, built on the promise of cheaper imports and cleaner air, has run into its most public challenge yet. Karnataka’s government says petrol sold at its pumps carried far more ethanol than the 20 per cent ceiling. The oil companies say the numbers cannot be trusted. Neither side has yet produced a result the other accepts.
What Karnataka says it found
The state’s Legal Metrology Department reported that 11 of the 14 petrol samples in its test results contained more than 20% ethanol, with a high of 31.2% in an IOCL sample. According to the state’s findings, an HPCL sample showed 30.5 per cent, BPCL 26.5 per cent, Nayara 26.1 per cent and Shell 25.5 per cent. The tests were done at the Shriram Research Institute in Bengaluru, which the state describes as accredited by the national testing body NABL. Samples came from seven districts including Bengaluru, Mangaluru, Kolar and Tumakuru.
Minister Rizwan Arshad warned that excess ethanol could cut mileage and harm filters, fuel pumps, injectors, hoses and seals. Chief Minister D K Shivakumar said the government had received thousands of complaints from motorists, ranging from reduced mileage to engines stalling midway. Karnataka wants legal action against offenders, compensation for affected owners through an E20 Damage Compensation Fund, and mandatory display of ethanol percentages at pumps.
What the oil companies say
Indian Oil, Bharat Petroleum and Hindustan Petroleum issued a joint statement rejecting the claims. They maintain that E20 petrol supplied across the country, including Karnataka, conforms to IS 17021, the Bureau of Indian Standards specification. Their objections are procedural. Under the Motor Spirit and High Speed Diesel Order of 2005 and the Marketing Discipline Guidelines of 2024, six one-litre samples must be drawn, with two for the dealer, two retained and two sent to a laboratory specified under the order. The companies say the October exercise involved samples collected without their representatives, that they never received the retention samples or outlet-wise details, and that the results came from a third-party lab rather than a specified one, with certificates too sparse to verify.
Their own data tells a different story. Indian Oil said all 56 E20 samples tested across Karnataka by the companies met specifications, with an average of 19.30%. The Ministry of Petroleum and Natural Gas has also rejected the state’s claim.
Karnataka’s rebuttal
The state has not backed down. It says every sample was drawn by officers authorised under the 2005 order and that labels were jointly signed with dealers. It points out that the first 63 samples were sent to the oil companies’ own laboratories, and that none of those reports gave the ethanol percentage. Testing by the companies’ own labs, it argues, makes them both accused and judge. And since blending is controlled at depots, it says, any excess is a failure at the source, not at the pump. Karnataka also says the oil firms’ fuel comes through six terminals serving the state.
Why Karnataka, and why now
The dispute appears confined to one state, but that does not mean the concern is. E20 has drawn complaints nationwide for months. A public interest petition in the Supreme Court alleged that millions of motorists had been forced to use fuel not designed for their vehicles, though the court declined to entertain it. What sets Karnataka apart is that its government went further than complaints. It sent its legal metrology officers to collect samples, sent them to an outside lab and published the results, the first time a state has put numbers against the oil companies’ compliance claims.
The sources reviewed do not establish a single reason for that choice. What is visible is a state government that has taken the volume of motorist complaints as grounds to act, and a political context in which it is run by the Congress and the Centre by the BJP. Congress leader Rahul Gandhi has joined in, with headlines citing his charge of “Petrol Chori” and the line that E20 had turned into 420. Karnataka’s government also alleged that industry concerns over E20 had been withdrawn or softened under pressure, citing a SIAM letter of 28 July flagging chloride and sulphur issues that was withdrawn within a week. These are the state’s allegations, and no response from the Centre on that point was found.
Two competing sets of numbers now sit on the table. Fuel samples are drawn from different outlets, tested in different labs under different protocols, and each side questions the other’s method. Only a joint, independently supervised re-test, with retention samples and open reports, can settle which numbers hold. Arshad has said he will convene a meeting with the oil companies. For millions of motorists wondering what is in their tank, the more basic demand, that the percentage be displayed at the pump, may prove the hardest for either side to resist.