Abstract: An improved nickel-based single crystal superalloy has both an extremely low sulphur content and a very low lanthanum, cerium, or lanthanum plus yttrium, or cerium plus yttrium, or content, whereby the amount while very low, is sufficient to react with the remaining available sulphur in the alloy and with sulphur from the fuel used in engine operation, such that the very thin, protective scale layer of aluminum oxide formed on the surfaces of the nickel-based alloy parts exposed to the very high temperatures incident in high efficiency turbine engines, will afford effective, long-life protection for the surfaces of these engine components, through the virtual elimination of spalling of the aluminum oxide scale during cyclic engine operations.