New Delhi, July 21 -- E20 petrol may result in a marginal 3-5 per cent reduction in fuel economy in certain older vehicles designed for E10 fuel, while extensive testing and real-world experience have not found any widespread engine damage or vehicle breakdown attributable to ethanol blending, the government has informed Parliament.

In written replies in the Rajya Sabha, Minister of State for Petroleum and Natural Gas Suresh Gopi said fuel efficiency depends on several factors, including driving habits, vehicle maintenance, tyre pressure, wheel alignment and air-conditioning load.

"Any reduction in fuel economy in certain older E10-designed vehicles is generally marginal (around 3-5%)," the government said. It added that E20 provides hi...