A report by the Automotive Research Association of India (ARAI) has revealed some important findings about the use of E20 fuel in vehicles designed for E10 petrol. E20 fuel contains 20% ethanol, while E10 contains 10% ethanol. The study was used by the government and vehicle manufacturers while planning the rollout of E20 fuel across India.
E20 Fuel May Affect Rubber Components
According to the report, E20 fuel can affect certain rubber parts in a vehicle's fuel system. Components such as hoses, gaskets, seals, and O-rings showed signs of wear and deterioration when exposed to E20 fuel. Because of this, the study suggested that these parts may need to be replaced in vehicles that were originally designed for E10 fuel.Also Read: Top 10 EV Battery Manufacturers in the World (2026)
Engine Durability Tests Show Mixed Results
The study also examined the impact of E20 on engine durability. During testing, one BS-IV engine performed normally with E20 fuel and showed no major issues.However, a BS-VI turbocharged engine developed a problem after 265 hours of durability testing. The issue was linked to the engine’s exhaust valve, raising concerns about how some modern engines may react to higher ethanol blends.
Exhaust Valve Failure Observed
Two vehicle manufacturers carried out four-wheeler durability tests. One manufacturer reported no engine problems even after 400 hours of testing with E20 fuel. However, another manufacturer observed a thermomechanical failure of the exhaust valve after engines completed a combined 809 hours of testing.This type of failure can occur when engine parts face extreme heat and repeated mechanical stress, causing the valve to crack, warp, or break. Experts noted that such failures could also be influenced by factors other than fuel.
Positive Results For Two-Wheelers And Emissions
The report found better results for two-wheelers. Tests conducted by three motorcycle manufacturers showed no durability issues, and performance remained acceptable with E20 fuel. ARAI also found no adverse impact on metallic components, and vehicle emissions stayed within legal limits. Starting, drivability, and overall performance remained satisfactory.However, fuel consumption increased by 2% to 6% compared to E10 petrol, depending on the vehicle. Despite the higher fuel usage, the study concluded that E20 remained within emission and performance standards.
Source: TOI Report