SUMMARY
Analysis of the pyrolytic fuel (liquid fuels obtained from the pyrolysis process of used tires), the physicochemicalcharacteristics correspond to gasoline, kerosene and diesel fractions. To determine the environmental sustainabilityof its use, combustion tests were developed in a diesel test engine (800 and 2500 rpm), in order to establish thecomparison with a commercial ecuadorian diesel. The obtained results proved based on the analysis of emissions andcombustion failures that this fuel cannot be a direct replacement for diesel.