The objective of this work is to study the addition of n-pentanol with the Calophyllum Inophyllum biodiesel to evaluate the performance, emission and combustion characteristics. Five different fuel blends are prepared by varying the n-pentanol fraction (10%, 20%, 30%, 40% and 50%) on volume basis with biodiesel. The prepared samples are tested in single cylinder constant speed CI engine. The addition of n-pentanol with biodiesel improves the thermal efficiency of the fuel blend up to 30% as compared to pure biodiesel. Among all fuel samples, B90P10 blend has shown higher brake thermal efficiency as 27% which is slightly lower than BTE of diesel fuel. The brake specific fuel consumption of biodiesel-pentanol blends are increased from 4.2% to 27.3% when compared to diesel fuel (D100). However, addition of n-pentanol more than 40% shows a negative effect in terms of performance and combustion. It is noted that biodiesel and n-pentanol blends have shown 15–43% and 33–50% reduction in hydrocarbon and carbon monoxide emissions compared to diesel. Further, the oxides of nitrogen and smoke emissions are found to be lesser for n-pentanol blends while comparing to the pure biodiesel. Among all blends, B90P10 is found to have better performance and emission characteristics. © 2019 Elsevier Ltd