To meet the demand for extruded aluminum alloys tolerant of exposures to 600C highly stable microstructures which are not currently available are required. In this study Sc and Zr have been added to extrudable Al-Mn-Mg alloys increasing recrystallization resistance beyond current levels. The aim of this research was to investigate the performance of Al-3(Sc,Zr) dispersoids in a commercial purity alloy.