Lubricating oil composition

A method of improving anti-shudder performance, comprising:

• lubricating a transmission with a lubricating oil composition, the lubricating oil composition including:
• a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. of 2 to 12 mm2/s;
• (a) one or more ashless dispersants;
• (b) at least one acidic phosphorus compound (B1) selected from the group consisting of:
• phosphoric acid, a phosphorus compound of the following structures, and a combination thereof:
• wherein R1-R3 are independently a C1-C20 hydrocarbyl group that may optionally contain an ether or thioether moiety;
• wherein R4 is a hydrogen atom or a C1-C20 hydrocarbyl group that may optionally contain an ether or thioether moiety
• wherein when the at least one acidic phosphorus compound (B1) is composed only of phosphoric acid, the lubricating oil composition additionally contains one or more neutral phosphorus compound (B2) selected from the group consisting of:
• phosphate esters, phosphite esters, hydrogen phosphite esters, thiosphosphate esters, and amine salts thereof;
• wherein the neutralization ratio of the (a) one or more ashless dispersants/the (b) at least one acidic phosphorus compound (B1) is 60 to 100%;
• (c) at least one friction modifier (C1), wherein the friction modifier is a reaction product of alkenyl-substituted succinic anhydride with a polyamine;
• and
• (d) at least one friction modifier (C2) selected from the oiliness agent group consisting of diols, ethoxylated amines, fatty acid esters, sulfurized fatty acid esters, amides and alcohols.