New Delhi: Conflicting claims made by the Karnataka government and oil marketing companies (OMCs) over ethanol content in petrol have exposed the need for an independent mechanism to verify fuel quality, Vinay Piparsania, former executive director at Ford India and founder of MillenStrat Advisory & Research, an automotive consultancy firm, told ThePrint.
He said petrol containing more than the prescribed 20 percent ethanol cannot be sold as an E20 blend, and any move towards higher alcohol percentage would require a separate fuel specification, vehicle compatibility assessments and advance notification to consumers.
The controversy emerged after the Karnataka government alleged that petrol samples collected from retail outlets in the state contained ethanol concentrations of between 26 and 31 percent. The OMCs, however, disputed the findings and maintained that the fuel supplied through their networks met the prescribed specifications. The Kerala government has also sent petrol samples for testing.
Piparsania said Karnataka’s concern was legitimate if petrol sold as E20 was found to contain 26–31 percent ethanol. Such a deviation would constitute a serious fuel-quality violation and a consumer-protection issue.
The OMCs have presented their own dataset comprising 893 samples tested across 27 states and Union Territories, including 56 samples from Karnataka. According to the companies, all these samples were within the prescribed 19–21 percent range.
“The OMC response is technically substantive and cannot be dismissed,” Piparsania said. However, he pointed out that these results largely came from the companies’ own quality-control systems and could not serve as the final independent assessment. He said the OMCs had also raised questions about Karnataka’s sampling procedures and the analytical methods used in the third-party test certificates.
“The OMCs have raised credible technical questions about the Karnataka testing, but the OMC’s own testing cannot by itself be the final referee. The dispute should be resolved through jointly collected samples and independent testing to the same prescribed standard. That is how you protect both consumer confidence, and the credibility of India’s ethanol programme,” he said.
Also Read: Karnataka alleges excess ethanol in E20 petrol, oil firms question testing methodology
Independent testing and OMC accountability
Piparsania suggested a joint sampling exercise, involving the state government, OMCs and an independent regulator or observer. Samples should be sealed, counterpart samples preserved, and their movement documented through a clear chain of custody.
Testing should be conducted at an independent laboratory accredited by the National Accreditation Board for Testing and Calibration Laboratories (NABL), using prescribed methods under the Bureau of Indian Standards (BIS) IS 17021 specifications. Complete results, including details of individual retail outlets, should also be made public, he said.
He said the controversy was less about whether ethanol content could be measured accurately and more about the independence and transparency of the testing process. Laboratory testing is technically reliable when sampling procedures, calibration and methodology are properly controlled. Simple field checks, including density measurements and water-extraction tests, can identify major deviations but should not replace prescribed laboratory testing.
A former senior executive of a major automobile manufacturer, speaking to ThePrint on condition of anonymity, said the controversy also pointed to shortcomings in the OMCs’ quality-control management. He said oil companies needed to be more transparent about their quality-control procedures, including whether ethanol blending takes place at refineries, depots or retail outlets, and what checks are carried out at each stage.
He added that OMCs are responsible for ensuring fuel quality, they need to strengthen monitoring and make their quality-control measures more transparent to consumers.
On the possible side-effects of the higher blend fuels, the executive said “OEMs have not yet tested the E30 fuel, so the side-effects are not yet known, but fuel efficiency will definitely drop.”
Higher blending raises vehicle compatibility concerns
Beyond the immediate dispute, Piparsania said any move towards E25 or E30 could have implications for vehicles currently designed and certified for E20 or lower ethanol blends.
E20 is a defined fuel specification under IS 17021, not merely a government target for ethanol blending. Moving beyond it would effectively introduce a different fuel specification.
He explained that higher ethanol concentrations could affect fuel efficiency, engine performance and the durability of vehicle components.
Ethanol has lower energy content per litre than petrol, meaning higher blends could increase fuel consumption. They also require a richer air-fuel mixture, which could affect cold starts, drivability and combustion if vehicles have not been calibrated for them.
Higher concentrations could also raise durability concerns involving fuel pumps, injectors, seals, hoses and other fuel-system components.
However, Piparsania cautioned against assuming that every E20-compatible vehicle would immediately suffer damage if exposed to E25 or E30. “That does not mean an E25 or E30 blend will suddenly damage every E20 vehicle. But E20 certification is not E30 certification,” he said.
India’s existing vehicle fleet includes cars, two-wheelers and three-wheelers designed for different fuel specifications, ranging from E10 to E20. An older E10 vehicle cannot automatically be assumed to be compatible with higher blends. Similarly, E20 certification does not establish compatibility with E25 or E30.
Piparsania said automakers have not yet tested vehicles with ethanol blends beyond E20, making it difficult to assess the potential impact on vehicle components and long-term performance. However, higher ethanol concentrations are likely to reduce fuel efficiency, he said.
Piparsania said the government would need a vehicle-compatibility roadmap that considers vehicle categories, age and fuel-system technology.
He said the government had reportedly tasked the Automotive Research Association of India (ARAI) with evaluating E25 compatibility in existing E10- and E20-compatible vehicles, including long-duration testing of around 60,000–70,000 km. The findings should be available before any wider move towards E25, he added.
Higher blends would also require validation covering fuel-system durability, material compatibility, corrosion, engine starting, emissions, fuel economy and drivability.
Also Read: Centre questions Karnataka’s Ethanol testing process. So what is the prescribed procedure
Consumers need advance notice
Piparsania said any decision to move beyond E20 must be accompanied by advance public notification, a defined transition period and adequate time for automakers to validate their vehicles.
Other safeguards should include mandatory labelling of fuel grades at petrol pumps, clear manufacturer warranty positions for different ethanol blends, and continued availability of compatible lower blends for older vehicles during the transition.
The government should also establish a mechanism for consumers to report complaints and seek compensation if fuel is found to be off-specification.
“Consumers should not have to determine, at their own cost, whether the fuel they purchased was within specification,” he said.
He said the dispute should be resolved through independent testing against the same prescribed standards to protect consumer confidence as well as the credibility of India’s ethanol-blending programme.
(Edited by Nardeep Singh Dahiya)
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