India has completed its transition to E20 petrol across the country, which means regular petrol sold at the pumps now contains 20% ethanol. The transition was achieved in April 2025, much ahead of the earlier 2030 target.The government is now preparing for the next phase of ethanol blending. It has exempted petrol containing 22-30% ethanol from central excise duty, putting it at the same tax level as E20. Separately, it has proposed changes to the Central Motor Vehicle Rules to formally recognize E85 and E100 fuels.For consumers, the main questions are how E20 affects the engine life and mileage of their vehicles and whether ethanol blending will eventually exceed 20%.
Debate: What happens next?
The immediate controversy is around E20, but the bigger concern is where India’s ethanol program goes from here. Bureau of Indian Standards has already notified fuel standards for E22, E25, E27 and E30. This has led to speculation that the government may eventually move the mandatory ethanol content in regular petrol beyond E20.Officials say any move towards higher mix will happen only after research, testing and consultation with stakeholders. The Petroleum Ministry has also said that the apprehensions regarding ethanol blending are not supported by scientific evidence. However, automakers are more cautious about blends beyond E20.He says any move to E25 or higher will require new validation of engines, fuel systems, materials, emissions and durability.
Why are drivers restless?
Many vehicle owners are still adjusting to the change from E10 to E20. The rollout happened rapidly, and consumers now have no option to buy petrol without 20% ethanol at regular pumps.Some owners have reported low mileage. Others have raised concerns about long-term reliability, particularly vehicles manufactured before 2012. Vehicles manufactured before April 2023 are also at the center of the current debate as they were not all originally certified for E20 use.
mileage is the first problem
For most vehicle owners, mileage is one of the most important factors. This is why the fuel-efficiency effects of E20 have become the most visible part of the controversy.The government and automobile companies acknowledge that E20 can reduce mileage. They typically reduce power by about 3-4% compared to E10.A 2021 study by the Automotive Research Association of India (ARAI), Indian Oil Corporation And the Society of Indian Automobile Manufacturers (SIAM) found that depending on the vehicle, fuel consumption with E20 can increase by 2-6% compared to E10.Maruti Suzuki It is said that the lower calorific value of E20 results in a drop in mileage of about 3-3.5%. For a 20 km/l car, this would be a reduction of about 0.6 km/l.However, consumers argue that real-world harm is often more felt. They also point out that they are buying more fuel without any price cuts to compensate for the lower energy content of ethanol-blended petrol.Vehicle manufacturers say mileage is also affected by many other factors, including tire pressure, driving style, gear selection, traffic, road conditions and vehicle maintenance.
What this could mean for older vehicles
The biggest concern is not just mileage, but also long-term vehicle health.Ethanol contains oxygen and absorbs moisture more easily than petrol. Over time, this may increase the risk of corrosion or degradation of some materials if the vehicle was not designed with ethanol compatibility in mind.Engineers warn that high ethanol blends can affect rubber and plastic parts in the fuel system. Components such as hoses, gaskets, seals and O-rings may be more vulnerable than metal parts. Concerns have also been raised about potential effects on valves, piston heads and fuel-system durability in older vehicles.Some people have raised the issue of having more difficulty starting cold with E20 fuel in the winter, but automakers said there should be no such problem.The risk is not the same for all vehicles. Newer ones are more likely to have ethanol-compatible materials and calibrations. Older vehicles, especially those originally designed for E0 or E10 fuel, are more likely to encounter long-term compatibility problems.
What the 2021 study found
The 2021 ARAI assessment is central to government and industry advocacy for E20. The study found no significant corrosion, pitting or discoloration of the metal components tested. This has been used to argue that E20 does not cause widespread damage to vehicles.
How does blending work?
However, the same report also states that some rubber materials, including NBR-PVC blend emulsions, perform worse with E20 than with E10. It recorded SIAM’s view that rubber parts used in fuel-system components, such as hoses, gaskets, seals and O-rings, may deteriorate and require replacement for E20 use.
Why do automakers say E20 is safe?
Major automobile manufacturers have publicly supported the use of E20 in existing gasoline vehicles.At a recent government press conference, representatives from Maruti Suzuki, Toyota Kirloskar Motor, Hyundai Motor India, Hero MotoCorp, TVS Motor Company and Bajaj Auto said that years of testing and real-world experience show that E20 is already safe for vehicles on the road.Toyota Kirloskar Motor’s Vikram Gulati said the E20 was introduced only after rigorous testing, including on older vehicles, and India’s certification process follows internationally accepted UNECE standards. Maruti Suzuki cited service-network data to support its position. The company said it serviced 2.84 crore vehicles in FY26, which includes over 1.5 crore vehicles older than three years and hence, not originally certified for E20. According to the company, it found no evidence of E20-related corrosion, abnormal wear or reduction in component life.Maruti also said that existing petrol vehicles do not require retrofitting to use E20, arguing that modern vehicles are engineered with safety margins beyond basic E20 compatibility.Hero MotoCorp made a similar claim for two-wheelers, saying its service data showed no higher incidence of damage in vehicles using E20 compared to earlier petrol blends.
What is increasing the controversy?
Although the E20 was introduced earlier, nationwide availability was only achieved in April 2025. This is why complaints about mileage loss and potential vehicle impact are becoming more visible.Quick rollout is also important. If the original 2030 target had remained in place, many older E0 vehicles built before 2012, and a large portion of E10-compliant vehicles built after 2013, would have completed the majority of their useful lives before E20 became the national standard. The notification of standards for E22, E25, E27 and E30 has raised concerns. Many motorists now worry that E20 may only be an intermediate step and that higher ethanol blends may become mandatory in the future.
E25 is a huge leap forward from E20
Automakers have supported E20, but they are more cautious about E25 and higher blends. “Increasing the ethanol content will require them to re-verify engine calibration, fuel-system durability, corrosion resistance, material compatibility and emissions performance,” said one automotive engineer.Vehicles currently certified for E20 may require new homologation and regulatory approval for E25 or higher blends. This will involve compliance costs, which may ultimately be reflected in vehicle prices. Higher ethanol content may also make mileage loss more noticeable because ethanol contains less energy than gasoline. That’s why any move beyond E20 is likely to face intense scrutiny from both automakers and consumers.
E85 is not for regular cars
E85 should not be confused with E20 or E25. It is a high-ethanol fuel intended only for flex-fuel vehicles.Flex-fuel vehicles are specifically engineered to run on a wide range of ethanol-petrol blends, from E20 to E85 or in some cases pure ethanol. They require compatible fuel systems, engine calibration, and materials that can withstand high ethanol content.
Petroleum Minister Hardeep Singh Puri inaugurating E85 pump in Delhi
Maruti Suzuki has showcased the E85 compatible flex-fuel WagonR. Hero MotoCorp has unveiled flex-fuel versions of the Splendor Plus and HF Deluxe that can run on a blend of up to E85. Suzuki Motorcycle India also offers a flex-fuel motorcycle.Using E85 in a conventional gasoline vehicle can damage components, reduce performance and affect reliability. Toyota has also stressed that E85 is for flexfuel vehicles and should not be seen as a replacement for E20 in normal petrol cars.
Can motorists choose the fuel?
Currently, consumers have no choice between regular petrol and E20. E20 is now the standard petrol sold across the country. This differs from Brazil, where motorists can choose between different ethanol-petrol blends based on vehicle compatibility, price and availability. Brazil’s flex-fuel ecosystem evolved over several decades and gives consumers multiple options at the pump.In India, experts say the government should consider making higher ethanol blending optional rather than mandatory, at least initially. This will allow compatible vehicles to be used while protecting owners of older or non-compatible vehicles.Going forward, India may develop two parallel fuel ecosystems. Regular petrol can gradually move from E20 to a higher blend like E25. Separately, E85 and E100 pumps will serve flex-fuel vehicles.The rollout of E85 has already begun, with India’s first E85 retail outlet opened in New Delhi. The next phase is expected to focus on Delhi-NCR, Mumbai, Pune and Ahmedabad, followed by wider expansion of E85 dispensing stations.
Why is the government emphasizing on ethanol?
India is a major importer of crude oil, making it vulnerable to global price shocks and supply disruptions. Ethanol blending aims to reduce oil imports, save foreign exchange, improve energy security and create a larger market for domestically produced ethanol.The government also argues that ethanol blending can help reduce emissions and support farmers by creating demand for ethanol feedstock. The benefits of blending have received renewed attention after geopolitical tensions impacted global fuel supplies and crude oil prices. The long-term outlook appears to be similar to Brazil’s flex-fuel model. The difference is that Brazil built its system gradually and allowed consumers to choose. The change in India has been rapid and as of now, motorists do not have the option to buy 100% petrol instead of E20.
test, trust, trust
The government and automakers say E20 is safe, tested and essential to India’s energy security. However, many consumers remain concerned about the impact on mileage, maintenance and aging vehicles.The next phase will be more sensitive. Moving from E20 to higher blends will require strong evidence, transparent testing and clear communication. Consumers will also want answers on whether older vehicles require component replacement, whether fuel prices will reflect lower mileage, and whether they will have a choice at the pump.
