Resurfaced ARAI Study Warns E20 Fuel Degrades Rubber in E10 Vehicles

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A 2021 study by the Automotive Research Association of India (ARAI) has recently resurfaced, sparking fresh conversations amid growing public concern about the effects of E20 fuel on older vehicles. E20 is a biofuel blend consisting of 20% ethanol and 80% petrol, designed to reduce emissions and decrease reliance on fossil fuels. While the ARAI testing showed that E20 does not cause significant corrosion or damage to metal engine parts and coatings, the same cannot be said for non-metal materials.

As reported by multiple media channels, the research found that prolonged exposure to E20 can accelerate the deterioration of specific rubber and plastic components used throughout the fuel system. Materials like NBR/PVC blends, Epichlorohydrin, and PA66—which are commonly used to manufacture seals, gaskets, O-rings, pipes, and hoses—experienced more degradation when exposed to E20 compared to standard commercial gasoline. Additionally, a corresponding NITI Aayog report highlighted a slight dip in fuel efficiency, noting that vehicles could experience up to a 6% decrease in fuel economy on average when running on the E20 blend.

Fortunately, if you own a newer vehicle manufactured from April 2023 onward, there is no need to worry; these cars are already built to be E20-material compliant, with some even having a tolerance for higher blends. The primary concern lies with older, E10-compliant vehicles that weren't designed to handle the higher ethanol concentration. While testing hasn't shown E20 to cause catastrophic engine failure, abnormal engine wear, or deposits, the degradation of fuel-system plastics and rubbers is a real possibility over time. For peace of mind, owners of older vehicles can look into aftermarket ethanol upgrade kits to swap out vulnerable parts, though they currently have to foot the bill themselves as manufacturers have not yet provided official kits. As the government explores even higher ethanol blends like E25 and E30 for the future, knowing your car's compatibility is the best way to protect your engine's longevity and performance.