In the present work approach to reduce the viscosity of the bio diesel and in order to improve the calorific value of bio diesel extracted from the mango seed oil 1, 4 dioxane has been used as a fuel additive. The methyl ester mango seed oil is prepared by employing transesterification process and blended with 2.5 %, 5%, 7%, and 10% of fuel additives blended with bio diesel. The optimum blend ratio of fuel additives was identified and 10% of additives shows better performance than others. The experiment was conducted in a single cylinder DI diesel engine coupled with eddy current dynamometer. From the experimental investigation it is found that, viscosity has been reduced up to 0.5% and it shows marginal increase in calorific value. The brake thermal efficiency for 10% additive fuel is slightly increased and significantly reduced NOx emission about 200 ppm.
