A single crystal alloy for high AN.sup.2 applications has a composition consisting essentially of from 4.0 to 10 wt % chromium, from 1.0 to 2.5 wt % molybdenum, up to 5.0 wt % tungsten, from 3.0 to 8.0 wt % tantalum, from 5.5 to 6.25 wt % aluminum, from 6.0 to 17 wt % cobalt, up to 0.2 wt % hafnium, from 4.0 to 6.0 wt % rhenium, from 1.0 to 3.0 wt % ruthenium, and the balance nickel. Further, these single crystal alloys have a total tungsten and molybdenum content in the range of from 1.0 to 7.5 wt %, preferably from 2.0 to 7.0 wt %, a total refractory element content in the range of from 9.0 to 24.5 wt %, preferably from 13 to 22 wt %, a ratio of rhenium to a total refractory element content in the range of from 0.16 to 0.67, preferably from 0.20 to 0.45, a density in the range of from 0.300 to 0.325 lb/in.sup.3, and a specific creep strength in the range from 106.times.10.sup.3 to 124.times.10.sup.3 inches. These alloys provide (a) increased creep strength for a given density and (b) specific creep strengths as high as or higher than all 2.sup.nd generation single crystal alloys with a significant decrease in density.