Improved aluminum casting alloys having are disclosed. The new aluminum casting alloys generally include manganese, zinc, and zirconium. In this regard, the new aluminum casting alloys generally include from 2.0 to 5.0 wt. % Mn, 1.0-4.5 wt. % Zn, and from 0.05 to 0.9 wt. % Zr, the balance being aluminum, optional secondary elements, iron and silicon impurities, and other elements, where the new aluminum casting alloy includes not greater than 0.15 wt. % each of the other elements, and where the new aluminum casting alloy included not greater than 0.50 wt. % in total of the other elements.