Karnataka Alleges Petrol Contains Up To 31% Ethanol As Motorists Report Engine Trouble

Karnataka has alleged that petrol sold at some outlets in the state contains far more ethanol than the permitted 20 per cent, after thousands of motorists complained of falling mileage and engines stalling on the road. Chief Minister DK Shivakumar said on Sunday that samples collected from 67 locations are being tested, and the state will present its evidence at a press conference on Monday.

What The Tests Reportedly Found

Karnataka's food and civil supplies minister Rizwan Arshad had earlier said that tests on samples from seven districts, including Bengaluru and Mangaluru, found ethanol concentrations as high as 31.2 per cent. According to the state government, 11 of 14 samples tested exceeded the prescribed 20 per cent limit under the Centre's E20 programme.

The samples were tested by the Bengaluru-based Shriram Research Institute. The figures released by the government put Indian Oil Corporation at 31.2 per cent ethanol, Hindustan Petroleum at 30.5 per cent, Bharat Petroleum at 26.5 per cent, Nayara at 26.1 per cent and Shell at 25.5 per cent.

Shivakumar said the investigation, around 30 per cent complete, has expanded beyond petrol pumps to the blending and distribution stages, after thousands of motorists complained of poor mileage and engines stopping while in motion.

Oil Companies And The Centre Push Back

The oil companies have firmly rejected the findings. Indian Oil, Bharat Petroleum and Hindustan Petroleum said in a joint statement that their petrol complied with the Bureau of Indian Standards specification for E20 fuel. They questioned the sampling and testing procedures used in the state's October exercise, arguing that the findings rested on third-party laboratory certificates that did not follow the prescribed statutory and technical procedures.

The Ministry of Petroleum and Natural Gas has also rejected the claim, saying all 893 samples of E20 petrol drawn from public sector oil marketing companies across 27 states and union territories conformed to prescribed quality standards.

The Centre has acknowledged that E20 can cause a marginal 3 to 5 per cent drop in fuel efficiency in some vehicles designed for E10 petrol, while maintaining that studies found no significant adverse impact on engine components when the fuel meets prescribed standards.

Why This Row Matters For Every Motorist

India's E20 programme blends up to 20 per cent ethanol into petrol, a policy meant to cut crude oil imports, reduce emissions and support the farmers who supply the ethanol. With crores of vehicles using this fuel every day, even a small question over its quality becomes a national concern.

That is why the complaints matter. Motorists in Karnataka have reported lower mileage, repeated engine stoppages and mechanical problems — symptoms drivers across the country have been discussing since the E20 rollout gathered pace.

What Happens Next

All eyes are now on Monday's press conference, where Karnataka's minister is expected to present the test documents and explain how the samples were collected. The state says it has informed the Centre about all 67 locations where samples were taken, and that its teams are also inspecting fuel dispensing machines and vehicles.

For now, the claims remain allegations. The findings of the ongoing investigation are awaited, and the outcome could shape the national debate on how E20 fuel quality is checked.

The ethanol row has put India's E20 fuel programme under its sharpest scrutiny yet. With a state government and the country's biggest oil companies flatly contradicting each other, verified evidence — not claims — will decide the matter.

Have you noticed lower mileage or engine trouble after filling petrol recently? Tell us in the comments below.