US Patent 7906466 Finished lubricant with improved rust inhibition

A finished lubricant having a kinematic viscosity at 40° C. between about 90 and 1700 cSt that passes the 4 hour TORT B rust test, comprising:a) greater than 65 weight percent API Group III base oil, API Group IV base oil, polyinternal olefin base oil, or mixtures thereof; andb) between about 0.10 wt % and about 5 wt % solubility improver. The solubility improver has an aniline point less than 50° C., or even lower. The finished lubricant can additionally comprise a mixture of amine phosphates.