India’s aggressive push towards ethanol-blended petrol may now be creating fresh concerns for many vehicle owners, especially those driving older petrol cars and two-wheelers.
A new LocalCircles survey has found that nearly 5 in 10 owners of petrol vehicles purchased in 2022 or earlier say they have experienced lower mileage after the rollout of E20 petrol in 2025.
The findings have added a new consumer angle to India’s large ethanol-blending mission, which the government has strongly pushed as part of its effort to reduce crude oil imports and cut dependence on foreign fuel.
India achieved its E20 rollout target years ahead of schedule and has increasingly put its foot down on expanding ethanol-based fuel adoption across the country. The government sees ethanol blending as an important long-term strategy to reduce oil imports, save foreign exchange and support domestic farmers linked to sugarcane and maize production.
But the latest survey suggests that some consumers believe the shift may be coming with hidden costs.
According to the survey, which gathered responses from over 24,000 vehicle owners, a large number of respondents said their vehicles were now giving lower average after the introduction of E20 fuel.
Among those reporting a decline, around 25% said mileage had dropped by over 20%. Another 7% said the fall was between 15% and 20%, while 13% reported a decline between 10% and 15%.
The findings are significant because official estimates earlier suggested E20 fuel could reduce fuel efficiency only marginally, generally in the range of 1% to 6%.
That gap between official projections and consumer experiences is now emerging as one of the biggest talking points around E20 petrol.
For everyday consumers, lower mileage directly means spending more money on fuel every month.
At a time when petrol prices remain elevated in several cities, even a small drop in fuel efficiency can significantly increase monthly commuting costs for middle-class households.
One important detail highlighted in the survey is that most complaints are coming from owners of vehicles purchased before 2023.
That is important because many older petrol vehicles were originally designed for lower ethanol blends such as E5 or E10, not E20.
Ethanol behaves differently from conventional petrol. It has lower energy density, which means vehicles may need to burn slightly more fuel to travel the same distance.
Industry experts have also earlier pointed out that ethanol can absorb moisture more easily and may affect certain rubber and plastic components in older fuel systems over long periods.
The survey suggests this may be one reason why some owners feel their vehicles are not performing the same way after the E20 rollout.
The survey also found that concerns are not limited only to mileage.
Nearly 29% of respondents said they had experienced unusual wear and tear, repairs or vehicle-related issues after using E20 fuel.
Some respondents reported problems linked to fuel lines, carburettors and engine performance.
While these claims are based on consumer responses and not a scientific mechanical study, the findings are likely to add to the growing debate around how older vehicles are coping with higher ethanol blends.
India’s ethanol-blending programme has been one of the government’s biggest energy-transition projects in recent years.
The country imports nearly 87% of its crude oil requirements, making it highly vulnerable to global oil price shocks and geopolitical disruptions.
By increasing ethanol blending in petrol, the government aims to: reduce crude oil imports, lower foreign exchange outflow and support domestic agriculture.
The E20 target was originally planned for later years but was achieved ahead of schedule.
The government has also been encouraging automobile manufacturers to prepare vehicles compatible with higher ethanol blends in the future.
The report points out that India is already preparing for even higher blending levels beyond E20, including E22, E25, E30 and eventually E85 in some segments.
That makes the current concerns around E20 even more important because they raise broader questions around how older vehicles will adapt if ethanol blending increases further.
For policymakers, ethanol blending is largely seen as a long-term economic and energy-security strategy.
But for consumers, the immediate concern is simpler: Does the vehicle now consume more petrol than before?
If mileage drops while fuel prices remain high, the monthly cost of running a vehicle rises automatically.
And if repair or maintenance costs also increase, owning older petrol vehicles could gradually become more expensive.
The survey also indirectly raises concerns around the long-term resale value and lifespan of older petrol vehicles if higher ethanol blends become the norm across India.
The findings are based on a LocalCircles consumer survey and reflect responses shared by vehicle owners. The report is not a government-backed technical study or peer-reviewed scientific research.
Still, the survey highlights a growing consumer debate that is likely to become more prominent as India deepens its shift towards ethanol-based fuels.