A process for producing a lubricating base oil blend which comprises (a) recovering a Fischer-Tropsch derived distillate fraction characterized by a kinematic viscosity of about 2 cSt or greater but less than 3 cSt at 100 degrees C.; and (b) blending the Fischer-Tropsch derived distillate fraction with a petroleum derived base oil selected from the group consisting of a Group I base oil, a Group II base oil, a Group III base oil, and a mixture of two or more of any of the foregoing conventional base oils in the proper proportion to produce a lubricating base oil blend characterized as having a viscosity of about 3 or greater; also the base oil blends, finished lubricants, and their use in internal combustion engines.