Automobile emissions are the main source of GHG accumulation in environment. With an increasing concern for world environment, it is of great importance to analyze the reasons for vehicle emissions and to figure out the ways to minimize these emissions without sacrificing vehicle performance. Since old engines produce more emissions and it will be difficult to entirely stop their usage especially in developing and under-developed nations, it is desired that appropriate emission reduction technologies are tested on such old engines to see if these technologies could reduce the emissions from such engines substantially with economical acceptability. This study tried to fulfill this requirement by testing an uncoated wall-flow type ceramic DPF with a Bharat Stage-1, variable speed, direct injection, water cooled, 4 cylinder, C.I. engine in laboratory in India. Engine was run at 1500, 2000, 2500 and 3000 rpm at 0, 25, 50, 75 and 90 Nm torque, both with and without the DPF. Gas analyzer and smoke meter were used to measure emissions. The results, in form of engine performance (BSF and BTE) and smoke, NOx, CO and CO2 emissions, were analyzed and conclusions were drawn. It was found that using DPF, particulate matter emissions (smoke) were almost entirely eliminated, without impacting the engine performance adversely, and this was the biggest need. Also, it does not involve a big investment and the regeneration cost is also small. Off-board regeneration was done for maximum effectiveness by taking out and heating the DPF in an electrical resistance furnace at 650°C for 10 hours