The Central government on Wednesday said that E20 petrol may lead to a marginal reduction in fuel efficiency in some older vehicles originally designed for E10 fuel, but that there is no verified evidence of widespread engine damage or vehicle breakdowns linked to ethanol-blended petrol. 

In a written reply to questions in the Rajya Sabha, Minister of State for Petroleum and Natural Gas Suresh Gopi said that any reduction in mileage in older E10-designed vehicles is generally limited to around 3-5 per cent.