Around 59% of owners of petrol vehicles bought in 2023-24 reported a mileage drop of over 10% after the rollout of E20 petrol in early 2025, a LocalCircles survey found. About 25% said the drop exceeded 20%, far above the 3-5% that the government claimed. Among owners of pre-2023 petrol vehicles, 66% said mileage had fallen by over 10%.