Bengaluru: Vehicle complaints rise amid concerns over ethanol-blended petrol

Bengaluru: Vehicle service centres across Bengaluru are reporting a rise in complaints of engine stalling, starting trouble and reduced fuel efficiency, with motorists increasingly raising concerns about the impact of ethanol-blended petrol on vehicle performance.

Service managers at major two-wheeler and car service centres said they had noticed an increase in complaints, particularly involving older vehicles.

A manager at a leading two-wheeler service company told DH that several customers had reported motorcycles stalling midway and having difficulty starting. During routine servicing, mechanics had also noticed sticky deposits inside engines, which they suspected could be obstructing
fuel systems and affecting
performance.

“When we service these vehicles, we notice sticky formations inside the engine that clog the system. We have therefore started suggesting that customers use certain aftermarket additives while refuelling,” the manager said.

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Another mechanic at a service centre in Peenya said BS4 vehicles and older bikes were more affected.

“Ethanol absorbs moisture, and this affects rubber hoses and gaskets. In older vehicles, we are seeing corrosion in the fuel tank and carburettor blockages. The company has not issued any official circular, but we are advising customers not to leave their bikes idle for many days with the same fuel,” he said.

A service manager at a major car service company said motorists had also reported a significant drop in mileage, with some claiming a reduction of 20–25%. Issues involving fuel tanks had also been flagged in recent weeks, the manager said.

“We are suggesting anti-corrosion agents to customers to help prevent corrosion and knocking and improve the vehicle’s overall performance and smoothness,” the manager added.

A rider said service providers had recently started offering an anti-corrosion liquid after servicing motorcycles and were advising customers to use it every time they refuelled, amid concerns over problems arising from ethanol-blended petrol.

The complaints come amid growing concerns over the compatibility of vehicles with higher ethanol blends. Chief Minister D K Shivakumar recently said the state government had tested petrol samples collected from 67 locations following complaints about allegedly high ethanol content in fuel.

India has adopted a 20% ethanol-blending target, with E20 petrol comprising 80% petrol and 20% ethanol. While newer vehicles are increasingly being designed to accommodate higher blends, older models may not have the necessary components and engine specifications.

Prof Krishnamurthy, head of the Department of Chemistry at Bangalore University, said engine compatibility was crucial in determining how vehicles responded to ethanol-blended fuel.

He explained that engines not designed for higher ethanol concentrations could experience knocking, potentially affecting spark plugs, cylinders and cylinder walls. A marginal decline in mileage and performance was also possible.

However, he cautioned against attributing the reported problems solely to ethanol without further investigation, pointing out that engine design, fuel quality and octane ratings also influenced vehicle performance.