In this contribution the efficiency maps of synchronous machines are analyzed. The tool developed to draw these efficiency maps allows considering the synchronous machines electromagnetic parameters and related losses. It will be exploited to analyze the effects of the different parameters on the efficiency maps. The developed tool is based on the synchronous machine’s electrical circuit model in the Park’s referential frame. The adopted modeling approach allows considering all types of classical synchronous machines: wound field synchronous machines (WFSM), permanent magnet synchronous machines (PMSM), hybrid excited synchronous machines (HESM) and synchronous reluctance machines (SRM). It can even indirectly consider the effect of magnetic saturation. These analyses will help identify parameters sets allowing optimizing the energy efficiency of synchronous machines for a given application like electrical traction. Particularly, the effect of saliency ratio will be considered and studied.