Abstract Alcohols are the renewable liquid fuels that can be blended with diesel fuel for fuelling compression ignition (CI) engine. This study is an experimental investigation of diesel-ethanol blend for maximum possible utilization and nano alumina was added as combustion enhancer to attain better results. The experimentation was conducted in four stages. viz. Solubility analysis of diesel ethanol in various proportions in a range of temperature 5⁰ C to 25⁰C and above; Testing of properties that are essential for fuelling CI engine; Modifying the injection timing to suit the maximum possible blend ; Testing the influence of nano alumina into diesel ethanol blends . Initially various proportions of diesel ethanol blends were prepared and tested for solubility in the said range of temperature with butanol as co- solvent. Stable blends were tested for properties such as cetane number, kinematic viscosity, oxygen content and flash point. Maximum possible blend was tested in CI engine with and without modification of injection timing. Maximum possible blend was ultrasonicated with two proportions of nano alumina (50ppm & 100ppm) and this blend was tested in the CI engine for performance at the modified injection timing. Results of the solubility test indicate that ethanol can be blended up to 45% by volume to diesel with 10% butanol as co- solvent and this blend was stable up to a lower temperature of 5⁰C. Results of the property test also depicts that the properties of this blend meets the minimum requirement of ASTM standards to fuel CI engine. The engine test results show that the advancement of injection timing of 29⁰ bTDC gave better results than the normal setting. The addition of nano alumina into the diesel ethanol blend improved the performance and emission characteristics significantly. This indicates that blend containing 100 ppm of nano alumina with 45% of ethanol produced similar brake thermal efficiency as that of diesel and the emissions produced by the blend were also found lesser than diesel at rated power condition. This enhances 55% of diesel reduction and conserves the diesel for some more periods.