Creep resistance is a major requirement for the use of magnesium in automotive powertrain components that are currently made of aluminum or cast iron. This paper summarizes various new magnesium alloys that have been developed in recent years for elevated temperature applications. The alloy development basis, mechanical properties, tensile and compressive creep resistance and microstructure of several new alloy systems (Mg-Al-RE1, Mg-Al-Ca, Mg-Zn-Al-Ca, Mg-Al-Ca-RE, Mg-Al-Sr, Mg-Al-Si, Mg-Si and Mg-Zn-RE) are critically reviewed. The potential applications of these alloys in automotive powertrains are also discussed.