Steamrolling ethanol-blended petrol puts seasoned mechanic, customers in trouble

Even as the Supreme Court on Monday (September 1, 2025) dismissed a petition challenging the nationwide rollout of 20% ethanol-blended petrol (E-20), seasoned mechanics are finding it difficult to retain their hard-earned legacy after the introduction of E-20. The use of E-20 is causing mechanical issues in the functioning of the fuel system, including the carburettor and engine, of vehicles, which is hard to fix due to the continued use of ethanol-blended petrol.

“Over the past year, I have been finding it hard to fix the mechanical issues in the fuel line system of vehicles. We hardly had to service the carburettor of the vehicles in the past, as its fuel supply system was simple and did not cause any major inconvenience to the riders or the mechanics,” said George Abhraham of Thrissur (name changed), a veteran mechanic who has been repairing only different models of Enfield Bullet for the last 40 years.

However, after the introduction of E-20, bikers have been repeatedly complaining about the fuel system degradation, missing firing order in the engine of the vehicle while throttling, rusting inside the carburettor contributing to starting troubles, power loss, etc. “Each time an issue is reported, we service the fuel line system, including the carburettor. However, the very next day, the customer will ring back saying that the problem has not been rectified, leaving us red-faced,” said Mr. Abhraham.

Shyam Hareendran, a native of Thiruvananthapuram who owns a 2008 model Gypsy, said the latest model vehicles with electronic fuel injectors are relatively free from complaints. However, the fuel injector attached to the engine unit of his Gypsy has repeatedly been reporting mechanical issues. It was only after the adoption of XP-100, premium high-octane petrol, that the issue was addressed temporarily. However, this is costly, as the premium petrol costs roughly about ₹160 per litre, he said.

Shalu V.S., another mechanic with 20 years of experience, said the blending of ethanol in petrol not only reacts with certain metals in the fuel supply system, but also reacts with rubber materials and gaskets attached to the fuel supply line. In addition, the presence of moisture in the fuel supply line, with its tendency to absorb moisture, has been causing reduced mileage, rough and irregular idling in the morning hours, and sluggish pick-up. The rust particles formed inside the carburettor also clog the fuel line, repeatedly necessitating the service of mechanics for replacing the system, he said.

The latest E-20-compliant vehicles are relatively free from these issues. Professor Kamal Krishna of the Automobile department at Sree Chitra Thirunal College of Engineering, Thiruvananthapuram, also the member of a technical committee formed to study the rising number of ‘accidental’ fires gutting vehicles in Kerala, said there were reports that the presence of ethanol in the fuel has been attracting a certain kind of bug to the rubber tubes attached to the fuel supply line, leaving small holes in them, causing vehicle fires in some cases.

Following this, the committee had suggested the State government to engage the Automobile Research Association of India to hold a detailed scientific study into the issue. Not only this, but the issues being reported by the customers and vehicle mechanics should also be subjected to thorough study as majority of these problems started being reported recently, said Mr. Krishna.

Although the adoption of ethanol or ethyl alcohol, a biofuel produced from plant waste called biomass, aims to reduce dependency on fossil fuels and cut down on carbon emissions, vehicles in the pre-pandemic era were not designed to handle ethanol’s reactive properties, experts said.