Bengaluru drivers report mileage drop, engine trouble after E20 petrol rollout

The nationwide introduction of E20 petrol — a blend of 20% ethanol and 80% fossil fuel — is causing significant distress among vehicle owners in Bengaluru. While the policy is aimed at cutting oil imports and emissions, commuters are reporting a sharp decline in performance, with many two-wheeler and older car owners experiencing frequent breakdowns.

A key complaint is a noticeable fall in fuel efficiency. K. Vinay, a delivery executive from J.P. Nagar, said his scooter's mileage has dropped by nearly five kilometres per litre since local stations switched to the new blend. He also reported erratic engine behaviour, including violent jerking at signals and sudden stalling, which he attributes to moisture buildup in the fuel tank.

Local garages are seeing a rush of vehicles with similar issues. Mechanics point to the chemical properties of high-concentration ethanol, which can damage components in vehicles manufactured before April 2023 that were not designed for biofuel compatibility. Common problems include clogged fuel injectors, ruptured rubber gaskets, and corroded fuel lines.

M. Anthony, a senior mechanic on Bannerghatta Road, explained that ethanol absorbs water from humid air. In a city like Bengaluru with frequent weather shifts, this mixture can separate and settle as a corrosive sludge in the tank. He noted that drivers often mistake this for adulterated fuel, but it is actually a result of chemical phase separation.

Transport expert M. N. Srihari has urged the government to prioritise user concerns, suggesting the rollout was too hasty. He believes authorities should have consulted stakeholders, explained the pros and cons, and built public confidence before implementation. While acknowledging ethanol's advantages, such as a longer shelf life and lower hazard in some emergencies, he stressed that the impact on fuel economy and repair costs must be weighed carefully.