Performance optimization of diesel engines is the subject of most researchers in the field of internal combustion engine in recent decades. One of the the most effective ways toward optimizing the performance of heating systems is exergy analysis. In this study, energy and exergy concepts are applied to evaluate the performance of a compression ignition engine with premixed gasoline fuel at various loads and constant speed. To reach proper performance of diesel engine with premixed fuel, in addition to first and second-law efficiencies, exhaust emission characteristics are reviewed. The results of this study indicated that greater portion of exergy transfer was due to the irreversibility, averaged 50% while at high loads exergy destruction rate decreased to %5 by using premixed gasoline fuel. Also, energy and exergy losses through exhaust emissions with premixed fuel will be reduced to about %8.5 and %16/5 (averaged on all engine loads), respectively. The use of premixed fuel gasoline can increase energy and exergy efficiency (maximum 8% at high loads) at all loads while NOX pollutants will be reduced. It was also found that both HC and CO emissions with premixed gasoline fuel will be increased at all loads.