Abstract: A process is disclosed for increasing the volume of lubricating oil base stocks recovered from a crude oil. A fraction having an atmospheric boiling range of about 675.degree. to 1100.degree. F. is recovered by vacuum distillation. This fraction is treated with furfural to extract a hydrocarbon mixture containing at least 50 volume % aromatic hydrocarbons. The raffinate is a lubricating oil base stock very high in paraffinic hydrocarbons and low in naphthenic hydrocarbons. The fraction extracted by the furfural contains at least about 50 volume % aromatic hydrocarbons and less than about 10 volume % paraffinic hydrocarbons. The mixture is hydrotreated to hydrogenate a substantial portion of the aromatic hydrocarbons. The hydrotreated product then is catalytically dewaxed. After removal of low boiling components, the finished lubricating oil base stock has a viscosity of at least about 200 SUS at 100.degree. F., a pour point of less than 20.degree. F.