The automotive sector is one of the main end-use markets for metal casting worldwide. The strong competitive pressure typical of this industry have been influenced in the recent years by sustainability as a new factor promoted by legislation, increased societal awareness of relevant instances and resource scarcity. Energy efficiency, although only a part of sustainability, is important for the metal casting practice because of its nature of large consumer of energy per unit product. Therefore, the effective use of appropriate energy efficient metrics in foundries is of great interest. In this work, a set of indicators developed by the authors (and derived by traditional metrics) to analyse the energy performance of foundries will be used to compare high pressure die casting processes producing car transfer cases with different suitable materials. On the basis of this analysis, it will be shown that the most energy efficient material can be identified whereas the traditional metrics cannot detect such opportunity.