Patent ID: 8480879

Claim:
A process for producing an API Group I base oil, comprising: a. obtaining a lower quality base oil not meeting API Group I specifications, having: i. a saturates level less than 90 weight percent, and ii. one or more suboptimal properties selected from the group consisting of a viscosity index less than 80, a pour point greater than −10 degrees C., and an Oxidator BN of less than 15 hours; and b. blending the lower quality base oil with a Fischer-Tropsch derived distillate fraction having: i. a Fischer-Tropsch pour point less than −9 degrees C.; ii. a Fischer-Tropsch viscosity index greater than an amount calculated by the equation: 28×Ln(Kinematic Viscosity at 100° C.)+80; iii. a Fischer-Tropsch Oxidator BN of greater than 20 hours; iv. a kinematic viscosity at 100° C. between about 1.5 mm 2 /s and about 5.5 mm 2 /s; and c. isolating the API Group I base oil; wherein the API Group I base oil has a viscosity index greater than 95, a pour point less than −7 degrees C., and an Oxidator BN of greater than 9.5 hours.