E20 petrol woes persist: 6 in 10 pre-2023 car owners report over 10% mileage drop, survey finds

More than a year after India completed the nationwide rollout of E20 petrol, a majority of owners of older petrol vehicles continue to report a sharp decline in fuel efficiency, suggesting concerns around the higher ethanol blend remain far from resolved. A new LocalCircles survey found that 67% of owners of pre-2023 petrol vehicles said their mileage had fallen by more than 10% since early 2025, while nearly half also reported rising maintenance costs and vehicle wear.

The findings come as India pushes ahead with higher ethanol blends beyond E20 as part of its energy transition strategy. They also follow the first known consumer court ruling related to E20 fuel, in which the Raipur District Consumer Disputes Redressal Commission directed Maruti Suzuki to replace a vehicle or refund its owner after recurring engine problems allegedly linked to E20 usage.

Among the 22,541 respondents who answered the mileage-related question, 67% said their vehicles were delivering more than 10% lower mileage than they had in early 2025. Nearly one in four reported a decline exceeding 20%.

The findings indicate that consumer complaints have remained broadly unchanged from previous surveys conducted in May and June, suggesting the issue has become persistent rather than temporary.

The survey also found that only 13% of respondents said they had noticed no impact on mileage.

According to the survey, 45% of owners of pre-2023 petrol vehicles said they had experienced an unusual increase in wear and tear or repairs involving components such as the engine, fuel line, fuel pump, injectors and fuel tank since early 2025.

The proportion reporting maintenance-related problems has risen steadily from 29% in May 2026 to 45% in the latest survey, pointing to mounting concerns among motorists.

Respondents cited issues including rough idling, increased engine vibration, harder cold starts, lower pickup and more frequent repairs.

A parallel LocalCircles survey of more than 22,000 owners of petrol vehicles purchased in 2023 and 2024 found that 59% also reported a mileage decline of more than 10% since early 2025. One in four respondents said the reduction exceeded 20%, despite these vehicles being marketed as E20 compatible.

LocalCircles said the scale of the reported mileage loss exceeds the Government’s own estimates and may indicate fuel quality issues beyond ethanol blending alone.

The organisation flagged the possibility of petrol adulteration or contamination, including ethanol concentrations above the mandated 20% and cases of water contamination within the fuel supply chain. It called for an independent investigation and regular, transparent testing of ethanol content at fuel stations.

The Government has acknowledged that E20 petrol can reduce fuel efficiency in older vehicles not calibrated for the blend, estimating a decline of around 3% to 5%. Controlled tests conducted by the Automotive Research Association of India (ARAI) have similarly indicated a mileage reduction of between 2% and 6%.

Union Road Transport and Highways Minister Nitin Gadkari has maintained that there is no conclusive evidence that E20 causes engine damage, while government agencies including ARAI, the Society of Indian Automobile Manufacturers (SIAM), the Indian Institute of Petroleum (IIP) and Indian Oil Corporation Limited (IOCL) have said their studies found no abnormal engine wear when E20 is used in vehicles built to applicable standards.

However, the latest survey suggests that many motorists continue to experience problems under real-world driving conditions.

On July 16, 2026, the Raipur District Consumer Disputes Redressal Commission ordered Maruti Suzuki and its dealer to replace a Grand Vitara Strong Hybrid purchased in 2024 after the owner reported repeated stalling, misfiring and declining performance following the use of E20 petrol.

If the vehicle is not replaced within the stipulated period, the Commission directed the company to refund ₹20.50 lakh, including registration and insurance costs, along with ₹1 lakh as compensation for mental harassment and ₹10,000 towards litigation expenses.

Maruti Suzuki has said it will challenge the order, maintaining that the vehicle was already compatible with E20 fuel.

While the ruling applies only to an individual case and remains subject to appeal, it is widely seen as the first judicial decision directly addressing consumer complaints linked to E20 petrol.

The Government is now preparing for the next phase of the programme, including possible introduction of E25 and higher ethanol blends. In May 2026, the Bureau of Indian Standards notified IS 19850:2026, establishing the regulatory framework for fuels beyond E20.

Officials have clarified that E25 remains under evaluation and that any commercial rollout will depend on ecosystem readiness.