Transmission fluid composition for improved wear protection

A transmission fluid composition comprising:

• a major amount of a lubricating oil basestock;
• and
• a minor amount of an additive package comprising:
• (i) a mixture comprising two or more compounds of structures (I):
• where groups R1, R2 and R3 are independently alkyl groups having 1 to 18 carbon atoms or alkyl groups having 1 to 18 carbon atoms where the alkyl chain is interrupted by a thioether linkage, provided that, in the mixture (i), at least some of groups R1, R2 and R3 are alkyl groups having 1 to 18 carbon atoms where the alkyl chain is interrupted by a thioether linkage;
• (ii) one or more compounds of structures (II):
• R4—S—R5—O—R7
• R4—S—R5—O—R6—S—R7 (II)
• where groups R4 and R7 are independently alkyl groups having 1 to 12 carbon atoms and R5 and R6 are independently alkyl linkages having 2 to 12 carbon atoms;
• (iii) one or more zinc dihydrocarbyl dithiophosphate compounds;
• and
• (iv) one or more oil-soluble or dispersible molybdenum-containing compounds.