Facing backlash, Centre likely to delay E25 rollout amid concerns over mileage and older vehicles

The Centre is expected to adopt a more gradual approach to introducing petrol blended with 25 per cent ethanol (E25), following growing concerns from motorists and automobile manufacturers over the impact of higher ethanol content on fuel efficiency and older vehicles. Government officials indicated that while policy measures have laid the groundwork for fuel blends containing more than 20 per cent ethanol, there is no immediate plan for a nationwide rollout of E25. Instead, the transition is likely to be phased in only after wider consultations, technical validation and greater readiness across the automotive ecosystem. The rethink comes against the backdrop of criticism surrounding the accelerated shift from E10 to E20 petrol. Although the National Biofuel Policy had initially envisaged widespread adoption of E20 by 2030, the target was achieved several years ahead of schedule, making E20 the standard petrol grade available across the country.

Recent policy decisions had fuelled speculation that the government was preparing for the next stage of ethanol blending. These include an excise duty exemption for petrol containing 22-30 per cent ethanol and the notification of fuel quality standards by the Bureau of Indian Standards (BIS) for higher ethanol blends. Officials, however, said these measures should not be interpreted as an indication of an imminent nationwide E25 rollout. According to people familiar with recent high-level discussions, the government believes the transition beyond E20 should proceed in a calibrated manner, allowing sufficient time for consumers, vehicle manufacturers and fuel suppliers to adapt. The issue has gained prominence after many vehicle owners reported a noticeable reduction in fuel economy following the introduction of E20 petrol. Owners of older cars and two-wheelers have also expressed concerns over long-term effects on engines and fuel-system components that were not originally designed for higher ethanol concentrations.

Officials acknowledged that while some consumer apprehensions may be overstated, others require scientific evaluation. The government is also expected to engage original equipment manufacturers (OEMs) to address complaints through technical guidance and consumer awareness. Automobile manufacturers have similarly urged caution, pointing out that moving to E25 would require additional engineering work, including recalibration of engines, testing of fuel-system durability, corrosion resistance and compatibility of materials with higher ethanol content. Vehicles would also need fresh homologation before being certified for commercial use. Industry representatives have indicated that such development and validation processes cannot be completed within a short timeframe, making a rushed transition impractical.

Experts note that ethanol contains lower energy content than petrol, which can lead to reduced mileage as blending levels rise. Higher ethanol blends may also affect cold-start performance in certain weather conditions and increase the risk of corrosion in older fuel systems because ethanol readily absorbs moisture. At the same time, ethanol offers several advantages. It has a higher octane rating than petrol, supports cleaner combustion, reduces dependence on imported crude oil and contributes to lower carbon emissions. These benefits form the basis of India's ethanol blending programme, which is aimed at improving energy security while supporting domestic sugar and grain producers. Automakers have already begun developing engines specifically optimised for higher ethanol blends, including designs with revised compression ratios to improve efficiency. However, industry executives maintain that widespread adoption of E25 will require significant lead time before such vehicles become common on Indian roads. Government sources reiterated that any move beyond E20 would be preceded by extensive testing, stakeholder consultations and a phased implementation strategy to minimise disruption for existing vehicle owners while ensuring that fuel infrastructure and vehicle technology are adequately prepared.