India's ministries give differing estimates on mileage loss from E20 petrol

In a parliamentary briefing, the road transport ministry referenced research by the Automotive Research Association of India, the Society of Indian Automobile Manufacturers and Indian Oil Corporation, indicating that vehicles designed for E10 gasoline may experience a 2-6% reduction in mileage when switched to E20, with the exact figure varying by vehicle class and vintage. Earlier, the petroleum ministry had informed the Rajya Sabha that any efficiency loss in certain older E10-compatible models is typically limited to about 3-5%.

Officials from both ministries highlighted that E20 offers a higher octane rating, superior anti-knock performance, cleaner combustion and smoother engine operation. They also noted that real-world fuel economy is influenced by factors such as driving conditions, driver behavior and maintenance practices. The government has dismissed social-media claims of a dramatic mileage drop linked to the new fuel blend.