High performance wind turbine gear oils and related methods

A method for producing a wind turbine gear oil composition, the method comprising:

• providing a base oil for a wind turbine gear oil composition, the base oil comprising a Group II/II+ extra heavy neutral oil base stock and an additional oil base stock selected from a Group III/III+ oil base stock and/or a Group V oil base stock;
• optionally, providing a performance additive package;
• and
• optionally, blending the base oil with a performance additive package,
• thereby forming a wind turbine gear oil composition exhibiting, as compared to a corresponding wind turbine gear oil composition wherein all of the Group II/II+ extra heavy neutral oil base stock is replaced with a Group IV oil base stock and, optionally, a Group III/III+ oil base stock and/or a Group V oil base stock, a property selected from the group consisting of:
• equivalent or reduced copper corrosion, determined by DIN EN ISO 2160;
• equivalent or reduced rust formation, determined by DIN ISO 7120;
• equivalent or reduced pour point, determined by DIN ISO 3016;
• equivalent or increased demulsibility, determined by DIN ISO 6614;
• equivalent or decreased foaming, determined by ISO 12152;
• equivalent or reduced oxidation, as determined by DIN EN ISO 4263-4;
• and
• any combination thereof.