In alignment with its carbon reduction commitments, India is transitioning towards higher ethanol-blended fuels, with E20 set for nationwide implementation by 2025. Ethanol is a renewable, domestically produced biofuel produced through fermentation of biomass such as sugarcane, corn. It possesses a higher octane rating and oxygen content compared to conventional gasoline, making it a favorable additive for improving engine performance and reducing emissions.
This study investigates the impact of E20 fuel on performance parameters of a 694 cc MPFI , water-cooled, twin-cylinder gasoline engine. For deriving maximum benefits of increased Octane rating of E20, compression ratio was increased to 12.5:1. Experimental analysis was conducted to assess the changes in combustion behavior, brake specific fuel consumption (BSFC), torque output, engine out emissions and thermal efficiency when operating on E20 compared to baseline gasoline (E10).
Base results indicate that E20 promotes more efficient combustion, owing to its higher laminar flame speed and elevated oxygen content, leading to a 3–4% improvement in low-end torque across real-world operating speed ranges. Conversely, on-road evaluations reveal a 3–4% fuel economy penalty with E20 relative to E10. Recovering E10-comparable fuel efficiency with E20 necessitates comprehensive engine calibration optimization, supported by targeted hardware modifications. Additionally, the high octane rating of ethanol reduces knock propensity, enabling the adoption of more aggressive ignition timing and higher compression ratios without compromising engine durability.
Thermal benefits are also taken into consideration, with a reduction in peak mid-catalyst temperatures by approximately 30–40°C, this enables stoichiometric operation throughout operating range without any enrichment. These improvements suggest that engines calibrated specifically for E20 can be benefited through fuel’s inherent properties to achieve higher thermal efficiency and lower tailpipe emissions.
In conclusion, the incorporation of E20 fuel in internal combustion engines shows notable advancements in engine performance and efficiency.