The E20 transition: fuel for debate

“Business is brisk,” says 53-year-old Abdul Aziz, a mechanic and co-owner of a repair shop in Karol Bagh’s Nala market, New Delhi, a bustling car repair bazaar. He says this flashing a wry smile, his mouth stained red by paan. The surge in business, he says, is being driven by a growing number of owners arriving with strikingly similar complaints. 

Over the past few months, motorists have been reporting a sharp drop in fuel efficiency and vehicles that jerk while driving. Mechanics call it “gaadi missing de rahi hai” — a symptom that often points to poor fuel delivery. According to Aziz and his business partner, Tanveer Ahmed Khan, the most common causes are clogged fuel injectors and blocked fuel filters.

The Nala market, as the busy automobile hub is locally known, is home to nearly 100 repair shops lined up in two parallel rows beneath a sprawling canopy of old trees. Signboards advertising engines, tyres, and spare parts hang overhead. Even in a steady drizzle, bonnets remain propped open as mechanics slide beneath dashboards and around engine bays to reach inaccessible corners. Worn tools, grease-stained hands, and decades of experience keep both the vehicles and the market humming.

Khan says mechanics are also noticing unusually heavy carbon deposits in fuel injectors, and carburettors of older vehicles, along with a rise in oxygen (O2) sensor failures. “Almost every car that comes in now has to be opened up for inspection,” he says.

According to the mechanics, these complaints are a relatively recent phenomenon that coincides with the nationwide rollout of petrol blended with 20% ethanol (E20) as the default fuel at retail outlets since April 2025, 5 years ahead of the original timeline under the Ethanol Blended Programme. The programme seeks to improve India’s energy security by reducing dependence on imported fossil fuels, support farmers by creating a market for ethanol feedstock, and lower vehicular emissions.

India’s push towards ethanol is driven largely by its dependence on imported crude oil. With nearly 88.5% of its oil requirement met through imports, the country remains vulnerable to volatile global oil prices, geopolitical disruptions and supply uncertainties. By blending petrol with ethanol made from domestically grown crops such as sugarcane, maize and surplus rice, the government aims to reduce its reliance on imported fossil fuels while creating a more secure and self-reliant energy system. According to the government, the Ethanol Blended Petrol (EBP) Programme has helped lower crude oil imports, encouraged the use of renewable, indigenous fuel and strengthened India’s energy security. The government claims it has already saved ₹1.97 lakh crore in foreign exchange, and substituted nearly 316 lakh metric tonnes of crude oil.

According to the government and the automobile industry, all petrol vehicles sold since April 1, 2023 are E20 material compliant. They acknowledge that E20 may lead to a 3–5% reduction in fuel economy because ethanol has a lower energy content than petrol. However, many motorists claim that their real-world experience has been different, with some reporting mileage losses of up to 20% after switching to E20. These anecdotal claims have not been independently verified and can vary depending on the vehicle, driving conditions and maintenance.

However, while the government commissioned the Automotive Research Association of India (ARAI), an autonomous body under the Ministry of Heavy Industries, to study the impact of E20 on vehicles, it has not made the empirical findings public. 

The absence of official data has fuelled speculation and competing claims over the blend’s real-world impact. A media report on the study had suggested that some E10-compatible vehicles showed deterioration of rubber components such as hoses, gaskets, seals, and O-rings, while issues were also observed in certain BS-VI turbocharged engines.

On the ground, mechanics in Karol Bagh say they are increasingly seeing fuel-system failures. Another component that is failing more frequently, they claim, is the fuel pump. Its fine valves often become clogged, while the electric motor can short-circuit if excessive moisture is present in the fuel, as a result of which repair bills have risen sharply.

A service that previously cost ₹3,000-₹4,000 can now run to ₹12,000-₹15,000. Replacing the fuel pump assembly costs around ₹7,000 for a small hatchback such as a Hyundai i10 or i20, while for larger vehicles the bill can climb to ₹15,000 or higher. Replacing an oxygen (O2) sensor costs about ₹2,000 a piece, and many vehicles have 2 sensors. In severe cases, an engine overhaul or replacement can push repair costs to around ₹40,000, depending on the model.

For mechanics in Karol Bagh, the spike in repair work has translated into better business. For car owners, however, it has meant more frequent workshop visits and significantly higher maintenance bills.

Besides Brazil, which is a global pioneer in ethanol blending, Paraguay, Thailand, Bolivia and Zimbabwe have already adopted E20 or higher ethanol fuel blends in various forms. In contrast, while most gasoline sold in the United States is E10, the country is gradually moving towards wider adoption of E15, alongside E85, which the U.S. defines as a fuel containing 51% to 83% ethanol. Europe too primarily uses E10.

On the road to change 

About three weeks ago, when 35-year-old Damajot Kaur, a schoolteacher based in Chandigarh, was out running errands, her 2012 Volkswagen Vento suddenly stalled in the middle of the road. When she tried to restart the engine, it would keep “missing”, implying engine misfire resulting in the vehicle jerking and moving unevenly.

She first took the car to an authorised Volkswagen service centre, where she was told it would cost her ₹18,000 for a new fuel pump and a total repair bill of ₹25,000, including labour. Instead, she approached a local mechanic, who fixed the problem for ₹7,000. Until the incident, Kaur says she had never heard of ethanol-blended petrol or the nationwide rollout of E20 fuel.

“People should know how E20 affects their vehicles, what its benefits are, what its limitations are, and whether it is compatible with their vehicle. Clear communication and consumer choice are important,” she says. She also argues that if consumers are expected to bear any trade-offs associated with the transition, they should see a corresponding benefit at the pump. “The price of the fuel should be fair,” she adds. But for now, many like her are contemplating buying the more expensive XP 100 fuel that is 60% costlier and sells at nearly ₹160.

Experts say ethanol itself is not the culprit. Instead, the problems may stem from older vehicles that were not designed or calibrated to run on E20 fuel, particularly models manufactured before 2023, or from issues related to fuel quality. “Ethanol behaves differently from petrol. It is a stronger solvent, so in older vehicles it can loosen deposits that have accumulated over time, occasionally leading to clogged filters or injectors. It also absorbs moisture more readily, making fuel quality, storage conditions, and the condition of ageing fuel-system components more important. These factors can contribute to symptoms such as rough idling or jerky driving,” explains Vinay Piparsania, Founder of Gurugram-based automobile consultancy MillenStrat Advisory & Research, and Former Executive Director at Ford India. He adds that the situation is different for vehicles specifically engineered for E20 fuel, that is those manufactured after 2023.

“Perhaps the most reassuring aspect of this transition is that manufacturers do not simply approve E20 — they engineer vehicles specifically for it,” says Piparsania. He explains that the entire fuel system is reviewed, including pumps, injectors, seals, hoses, pipes, and metallic components, to ensure long-term compatibility with higher ethanol content. The engine management software is also recalibrated to maintain the correct air-fuel mixture, performance, emissions, and cold-start behaviour. These changes are then validated through extensive durability testing before a vehicle is certified as E20 compatible.

“For consumers, this means that if a manufacturer has certified a vehicle for E20, it has undergone significant engineering and validation to support that claim,” he asserts. Therefore, he cautions against blaming E20 for breakdowns. “Vehicle compatibility, fuel quality, maintenance history, and component condition must all be evaluated before concluding that E20 is the root cause of any failure.”

Another key factor in the E20 debate

Those who work in the automotive space say contaminated fuel can independently cause injector fouling, poor drivability, fuel pump failures and, in severe cases, engine damage — the very problems mechanics say they are increasingly seeing in their workshops.

Fuel quality is also the issue that petrol dealers have been raising. They argue that ethanol’s hygroscopic nature, or its tendency to absorb moisture, has made fuel more vulnerable to water contamination if storage and dispensing systems are not properly maintained or upgraded. According to dealers, this has forced some retail outlets to discard hundreds of litres of E20 after it became contaminated with water and was deemed unfit for sale.

A petrol pump owner who wanted to remain anonymous as oil marketing companies have advised dealers against speaking publicly on the matter, says, “The underground tanks that store fuel often have some amount of water due to ingress during rains or moisture. There is also condensation from the fuel tanker that brings petrol to the petrol pump.” He adds that when the water content in the entire E20 stock in underground tanks exceeds 0.5%, ethanol binds with water. This results in phase separation, where the water-ethanol mixture settles at the bottom of the tank, while the petrol forms a separate layer above.

Also read: E20 fuel safe for use in all running vehicles, says ARAI

As fuel is drawn by the dispensing unit from the bottom of the underground tank, some vehicles may end up being dispensed this water-rich mixture instead of E20, pump owners further explained. They also said that the concerns were compounded in coastal areas where there is sub-soil water which can further contaminate E20 stock if the seals on the underground tanks are not properly in place.

Earlier this month, a video of an SUV owner in Bihar went viral after he claimed his vehicle broke down soon after refuelling. Holding up a bottle containing what appeared to be muddy, contaminated fuel, he alleged it was responsible for the breakdown. Toyota executives later said the incident was not caused by any defect in the vehicle but by fuel contamination. The YouTube content creator, Manish Kashyap, is among at least four who face an FIR from Nagpur Cyber Police for “false and defamatory” statements.

Oil marketing companies (OMCs), Indian Oil Corporation Limited (IOCL), Bharat Petroleum Corporation Limited (BPCL), and Hindustan Petroleum Corporation Limited (HPCL), have instructed petrol pumps to test underground tanks for water contamination 3 times a day and every 2 hours during periods of heavy rain. Dealers use a dipstick coated with a water-finding paste that turns red on contact with water. If contamination is detected, the outlet must inform the OMCs, which send a tanker to remove the water from the storage tank.

The losses can be substantial. One dealer said he had to discard about 600 litres of contaminated fuel, while another claimed losses of nearly 20,000 litres. There is no compensation from OMCs for such losses, they rued.

Even as they absorb these costs, petrol pump owners say they are often left to face irate customers whose vehicles develop problems after refuelling.

They argue that consumers need to be better informed about E20 and the precautions it requires. For instance, they say motorists should ensure that water does not enter their vehicle’s fuel tank during heavy rain or while washing the vehicle. However, dealers allege they have been actively discouraged from sharing such information with customers

“Some petrol pumps had put up hoardings saying E20 was being dispensed on government orders, but the oil marketing companies objected and directed us to remove them. They don’t want customers to know even this much,” says one dealer, requesting anonymity.

Communication is key

The concerns raised by petrol pump owners underscore the complexity of India’s transition to E20. Experts say the shift is not merely about introducing a higher ethanol blend at the fuel pump, but also about ensuring that every link in the supply chain is equipped to handle it.

“An E20 transition is not simply about changing the fuel in the vehicle. It is also an end-to-end engineering exercise involving refineries, logistics, storage terminals, fuel stations, vehicle manufacturers, and service networks. The transition succeeds only when every link in that chain is engineered and managed to the same standard,” says Piparsania.

So, if vehicles were already using E10 without much concern, why are more issues being reported with E20? “The move from E10 to E20 is more significant than simply doubling the ethanol percentage. The chemical characteristics of ethanol become more pronounced, making compatibility requirements more demanding,” explains Piparsania. 

But that is only part of the picture. “India’s vehicle fleet is one of the most diverse in the world, with millions of vehicles that were designed well before E20 became the intended standard. Many also have ageing fuel systems, or inconsistent maintenance histories,” he says. 

Add to this increasing awareness around ethanol blending. “As a result, owners are more likely to associate a fuel-system issue with the change in fuel,” says Piparsania. He feels both the government and auto industry players must use field data and systematic analysis to help separate perception from measurable engineering trends.

But couldn’t the transition from E10 to E20 could have been managed differently, automobile users ask? Piparsania feels this is an opportunity to strengthen the transition, but the move could have been done through more coordinated communication from the government, oil marketing companies, vehicle manufacturers, and dealer networks. 

“Equally important is a visible commitment from all stakeholders that any genuine issues arising during the transition will be investigated promptly, transparently, and resolved fairly. That assurance is essential for building consumer confidence,” asserts Piparsania. 

jagriti.chandra@thehindu.co.in

Edited by Sunalini Mathew and Amarjot Kaur