An aluminum alloy is disclosed that is suitable for casting and additive manufacturing processes. The aluminum alloy may be used in the casting and additive manufacturing of engine blocks and/or cylinder heads of modern internal combustion engines. The aluminum alloy exhibits improved ductility and fatigue properties suitable for elevated operating temperatures from about 250° C. to 350° C. The alloy includes about, by weight, 4-10% Copper (Cu), 0.1-1.0% Manganese (Mn), 0.2 to 5% Magnesium (Mg), 0.01-1.0% Cerium (Ce), 0.01-2% Nickel (Ni), 0.01-0.8% Chromium (Cr), 0.01-1.0% Zirconium (Zr); 0.01-1.0% Vanadium (V), 0.01-0.3% Cobalt (Co), 0.01-1.0% Titanium (Ti), 1-200 ppm Boron (B), 1-200 ppm Strontium (Sr), 0.5% max Iron (Fe), 0.1% max other trace elements, and balance of aluminum (Al).