The paper experimentally investigates the performance and exhaust emissions of a variable compression ratio engine fueled with 100%, 90%, 70% and 50% Jatropha bio-diesel and turpentine oil. In this paper, highly viscous Jatropha biodiesel is blended with relatively low viscosity turpentine oil in various proportions resulting in effective viscosity comparable with that of standard diesel with a view to developing a new alternative fuel which is comparable equally cost effective and eliminates dependency on conventional diesel fuel. Experimental analysis is carried out on ATE Make VCRE_MF single cylinder, naturally aspired, four stroke, and variable compression ratio diesel engine to study combustion performance and emission properties via conventional diesel fuel and different blends of Jatropha biodiesel with turpentine oil. Dual biofuel blend is found to be the greatest substitute to fossil (diesel) fuel in all aspects such as emissions and performance. Experiments have been accompanied at CR (compression ratio) of 15.5:1, 17:1, 18.5:1 and 20:1. Further, dual biofuel blend (JBT 50) resulted at full load and compression ratio 20, there was 2.17% increase in brake thermal efficiency and 13.04%, 17.5%, 4.21% and 30.8% decrease in CO, HC and NOx and smoke opacity respectively while CO2 was observed to increase by 11.04% respectively. (C) 2017 Elsevier Ltd. All rights reserved.