This study was based on two essential factors concerning biodiesel obtained from waste cooking oil: its engine exhaust emissions and its potential in light of general governmental policies on environmentally friendly alternative fuels in Turkey. the emission study was conducted with a 35.8 kW, 4-cylinder, 4-stroke, direct injection diesel tractor engine. Test results of five different blends of biodiesel produced from waste cooking oil were compared with European nonroad emission standards for diesel fuel. The results of the experimental study showed that the best blends were B10 and B20, which exhibited the lowest emission levels. The other dimensions of the study included an analysis of the potential of waste cooking oil as diesel fuel, with reference to fuel price policies applied in the past and proposed future policies on these same issues. The findings were presented and recommendations were given for the provision of waste cooking oil recycling via its use as an alternative fuel.