Lubricant blends and finished gear oils comprising a Fischer-Tropsch derived lubricant base oil fraction, a petroleum derived base oil, and a pour point depressant are provided. The Fischer-Tropsch derived lubricant base oil fraction comprises less than 0.30 weight percent aromatics, greater than 5 weight percent molecules with cycloparaffinic functionality, and a ratio of weight percent of molecules with monocycloparaffinic functionality to weight percent of molecules with multicycloparaffinic functionality greater than 15. The petroleum derived base oils comprises greater than 90 weight percent saturates and less than 300 ppm sulfur and is preferably selected from the group consisting of a Group II base oil, a Group III base oil, and mixtures thereof. These lubricant blends have surprising low Brookfield viscosities at -40.degree. C.