Premium synthetic lubricants comprise a synthetic isoparaffinic
hydrocarbon base stock and an effective amount of at least one, and typically a plurality of
lubricant additives such as a detergent, dispersant,
antioxidant,
antiwear additive, pout point depresant, VI improver and the like. The base stock is derived from a waxy, paraffinic, Fischer-Tropsch synthesized
hydrocarbon feed fraction having an initial
boiling point in the range of about 650-750° F. and continuously boiling up to at least 1050° F., by a process which comprises hydroisomerizing the feed and dewaxing the isomerate. The waxy feed has a T90-T10
temperature difference of at least 350° F. and is preferably hydroisomerized without any pretreatment, other than optional
fractionation. The
lubricant may also contain hydrocarbonaceous and synthetic base stock material. Lubricants, such as fully formulated multigrade automotive
crankcase and transmission oils formed by adding a suitable additive
package to the isoparaffinic base stock have exhibited performance superior to similar fully formulated oils based on both PAO and conventional,
petroleum derived base stocks.