The problems associated with the rising fuel demand constitute a severe challenge to globalisation. To overcome this problem biofuels are being promoted using a variety of strategies. Non-edible oil seeds are utilized as feedstock for generating straight vegetable oils and used for generation of biodiesel. The leftover seed cake after oil removal is converted to usable energy by pyrolysis process. The primary aim of this exploration is, to analyse and characterize bio-oil elicited out of de-oiled seed cakes of Deccan hemp and Karanja by pyrolysis, and employ a simple cost-effective methodology for utilisation in diesel engines. The maximal output of bio-oil was 49.5% with a particle-size of 1.5 mm at an optimal temperature of 450°c and heating rate of 5°c per minute. Density, viscosity, flash- point, pour-point, cloud-point and calorific value were employed to characterize the improved bio-oil as specified by American society for testing and materials (ASTM) standards. The density (ASTM D1298) being 978 kg/m3 and 960 kg/m3, viscosity (ASTM D445) 86.41centistokes (cSt) and 58.11 cSt, flash-point (ASTM D93) 50°c and 58°c, pour- point (ASTM D97) 6°c and 6°c, cloud-point (ASTM D2500) 10°c and12°c and calorific value (ASTM D4868) 22.44MJ/kg and 32.57 MJ/kg for bio-oil obtained through de-oiled Deccan hemp seed cake (DHSC) and Karanja seed cake (KSC) respectively. The analysis found that, bio-oil brought out by the pyrolysis method is inept for use directly in diesel engines as fuel so it is upgraded, blended with diesel and consequently used as an alternative energy source.