Auto industry executives said E20 fuel itself isn’t harmful to compliant vehicles, emphasising that the real issue is of adulterated or contaminated fuel reaching consumers.
Investigations triggered by complaints of stalled or non-starting vehicles repeatedly revealed elevated chloride and moisture levels in the petrol supplied. Given this, carmakers are calling for an independent body to test and certify fuel quality at pumps, ensuring what’s dispensed matches the prescribed standards and doesn’t damage engines. Fuel pump owners too have been highlighting the issue of contaminated petrol.
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“The maker cannot be the checker,” a senior industry executive said, requesting anonymity. “At present, oil marketing companies (OMCs) check the quality of fuel being dispensed at pumps. An independent body needs to be made responsible to examine whether the fuel being retailed meets the specifications outlined by BIS.”
Bureau of Indian Standards (BIS) norms states there should be “no addition of detergents, dispersants, silicon, chlorine containing additives, materials and metallic additives” in E20 fuel.
Also Read: Maruti Suzuki to hike car prices by up to Rs 30,000 from AugustIndia mandated sales of E20 petrol nationwide from April. Several consumers since have complained of falling fuel efficiency and, in some cases, damage to non-compliant vehicles. The government and industry have dismissed claims that E20 has harmed vehicles.
Production of vehicles, which are E20 material compliant began in April 2023. All vehicles sold in the country from April 2025 are both material and fuel compliant with E20.
“The quantum of ethanol being blended in petrol has doubled to 11 billion litres in the last two years,” said a second industry executive. “But while the ratio of ethanol in the fuel has increased, the infrastructure remains the same. Trucks which were used in alternate applications are carrying E20 fuel; depots and fuel storage tanks at petrol pumps have not been upgraded. Therefore, the instances of fuel contamination.”
Ethanol is hygroscopic in nature or has an affinity to water. Since the existing underground tanks and pipelines were designed to carry conventional petrol, higher ethanol blends can result in contamination of E20 stocks. Industry insiders said the underground tanks that store fuel often have some amount of water due to ingress during rains or moisture or condensation or from the fuel tanker that brings petrol to the outlet.
When the water content in the entire E20 stock in underground tanks exceeds 0.5%, ethanol binds with water because of its hygroscopic nature. This results in phase separation, where water-ethanol mixture settles at the bottom of the tank, while the petrol forms a separate layer on the top. When petrol is drawn from the underground tank, some vehicles may get the water-rich mixture from the tank’s bottom instead of E20 fuel, causing them to break down or fail to start.
Underground tanks and fuel pipelines made of mild steel also stand the risk of corrosion, if not upgraded, due to ethanol’s tendency to absorb water. This again leads to fuel contamination.
“The necessary infrastructure has to be in place,” said a third industry executive. “The auto industry body had informed the ministry of these risks of contamination towards the end of 2024. The BIS has already outlined the specs for E20 fuel. Instead of OMCs, possibly the BIS can be made responsible for carrying out checks to ascertain that these standards are being adhered to and that contaminated fuel is not being dispensed from fuel pumps.”