In this study, an irreversible Diesel cycle is investigated based on entransy method and optimization conducted by considering various scenarios. Entransy expressed as a heat transfer potential of a subject and it has begun to investigate as a new thermodynamic assessment parameter. This paper presents thermodynamical study of an irreversible Diesel cycle in order to optimize its performance. Moreover, four different strategies in the process of multiobjective optimization are proposed, and the outcomes are assessing separately. The first strategy is proposed to minimize the entransy dissipation rate and maximize the ecological coefficient of performance along with the maximum available work. Furthermore, the second one is suggested to minimize the entransy dissipation rate and maximize the ecological function along with the exergetic performance criteria. The third strategy is proposed to minimize ethe entransy dissipation rate and maximize the ecological function along with the thermal efficiency. Moreover, the fourth strategy is suggested to achieve the minimum entransy dissipation rate and maximum ecological function along with the entransy efficiency. Finally, the values of objective functions were obtained at the optimum conditions of each scenario; afterwards, compared with other scenarios to select the most appropriate one. Based on obtained results, maximizing ecological coefficient of performance is the most appropriate approach for optimization, since it leads to the maximum values of ecological function, exergetic performance criteria and thermal efficiency. In addition, in the fourth scenario the lowest entransy dissipation rate was achieved. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1475–1490, 2018