The Indian government has found itself issuing repeated clarifications following the mandatory rollout of ethanol-blended petrol last year. Criticism has continued to mount — with declining mileage and engine performance flagged as primary points of contention.

According to an Indian Express report, the government is likely to delay a proposed shift to E25 fuel amid growing backlash. The Centre has led a speedy rollout of ethanol blended fuel since 2023 — raising the percentage to E20 well ahead of its 2030 deadline. The fuel variant with 80% petrol and 20% ethanol is now the nationally available standard.

“There is a view (within the government) that the transition beyond E20 will need to be spaced out. That is the sense we have got from vehicle manufacturers too. The idea is to go to E25 in a calibrated, graded manner for existing vehicles,” a senior government official told The Indian Express.

A meeting was reportedly held at the seniormost levels of government last week to discuss the situation — with officials advising the need to scientifically address some of the genuine concerns. As per the Indian Express report, this included an effort to ask original equipment manufacturers to address the consumer complaints. The government believes sufficient time must be given for  ecosystem readiness, and consequently the transition to E25 fuel. 

Two recent government decisions have triggered concerns about an imminent rollout — although no formal date has been announced for dispensing E25 blended petrol. A central excise duty exemption for blended fuel (22%-30% ethanol) was announced recently and fuel standards notified by BIS for these blends.

What exactly is the issue?

Industry officials have acknowledged a minor trade-off to the E20 blend: a slight reduction in fuel efficiency because of its lower energy content. A Reuters report citing industry officials put this figure in the the 3% to 3.5% range — but surveys suggest a significantly higher impact. 

According to a recent survey by LocalCircles, a growing number of petrol vehicle owners are now reporting significant mileage drop and “unusual increase” in wear and tear. Complaints have surged sharply in recent weeks and the number of vehicle owners reporting a mileage drop higher than 10% “surged from 45% in May to 66% in June”. LocalCircles found that reports about unusual increase in wear and tear or need for repairs has nearly doubled from 29% to 55% in the same one-month period.

Older vehicles fare comparatively worse in this transition — with auto companies now concerned that filling internal combustion engine vehicles with E25 fuel could see some damage to parts. The hygroscopic nature of ethanol promotes water uptake and could lead to corrosion. Ethanol has lower calorific value than petrol, which results in a perceptible drop in mileage.  Regular cars running on higher ethanol blends are also harder to start on winter mornings because ethanol burns at a higher temperature than petrol. 

Mounting backlash 

Motorists have repeatedly questioned whether older vehicles could suffer corrosion, wear or reduced performance due to the growing use of ethanol. 

According to a recent ANI report, petrol dealers have also asked the government to reconsider its E20 fuel rollout. The President of the Odisha Petroleum Dealers Association flagged customer complaints, vehicle compatibility issues and a pending commitment on dealer margins as key points of contention during a recent interview. He also noted that dealers were being questioned by customers even though the fuel switch was a policy decision.

“Earlier, there were no complaints. Now that the E-20 has been introduced, we have problems,…A car’s carburettor gets jammed. There are many problems. They come and make a mess in the petrol pump. The owner of the petrol pump has nothing to do with it. The government has introduced it. It has sent us. We have sold it,” Sasanka Sekhar Sahu told ANI. 

He also suggested that the Association planned to formally request the government to reconsider its E20 mandate — proposing a return to E10 until vehicle compatibility improved. Sahu signaled that dealers support the broader ethanol programme but want a phased approach and start with a 10% ethanol blend rather than a 20% that aligns with vehicle readiness and ensures margins keep pace with costs. 

Govt pushes back against ‘rumours’

Officials have pushed back vehemently against the claims — noting that years of testing and service data showed no evidence of widespread vehicle damage. Union Minister Hardeep Singh Puri also dismissed concerns about E20 fuel attracting pests or damaging vehicle engines as mere “rumours” circulating on social media. He insisted that the government remained open to constructive criticism, but urged people to rely on scientific evidence rather than misinformation. 

“We did not invent the concept of ethanol usage; work on this has been going on for a century…India, the Congress government was the first to formulate a plan for this in India…They use it in racing cars also, the acceleration increases. Mileage, yes, it may drop a little,” Puri said in separate remarks last week.

The controversy intensified this week after Attorney General R. Venkataramani told a court hearing that E20 was an “experiment” whose results would only come out next year. The government has denied the remark was ever made.