The present investigation is carried out on biodiesel practicability over the existing non-renewable fuel due to its environmental dilapidation effect and oil crisis. Biodiesel was extracted from crude oil by transesterification, and its properties have been compared with those of neat diesel according to ASTM standards. Then, the blends of biodiesel are prepared for experimental analysis. Experimental results from our previous research study, the best blend was optimized. Then, the standard CI engine with Hemispherical Piston Bowl Geometry (HPBG) is modified to Toroidal or Split type Piston Bowl Geometry (TPBG) and Re-Entrant Piston Bowl Geometry (RPBG). Experimental works were carried out for preheated optimized blend, neat diesel with modified Piston Bowl Geometries. The engine characteristics results were compared with these altered conditions. The modified PBG with preheated biodiesel blend resulted in better Performance and Combustion characteristics. The preheated biodiesel blends indicated significant depletion in the emission of harmful particulate matter such as CO, NOx, and unburnt Hydrocarbons.