Patent ID: 7947636

Claim:
A method of improving the friction durability of a transmission fluid comprising: preparing a transmission fluid by adding to a base oil, an additive composition comprising: an ashless dispersant, present in an amount from 3 to 5 wt % based on the transmission fluid and an oil-soluble aliphatic tertiary amine component, wherein the oil-soluble aliphatic tertiary amine component comprises an oil-soluble aliphatic tertiary amine of the formula wherein the R1 group comprises an alkyl or alkenyl group having about 1 to about 4 carbon atoms, and the R2 and R3 groups independently comprise any one of an alkyl, an alkenyl, and an alkynyl group, having from about 10 to about 30 carbon atoms, wherein the oil-soluble aliphatic tertiary amine is present in an amount from about 0.5 to about 8 percent by weight, and wherein the power transmission fluid exhibits improved friction durability relative to a power transmission fluid not containing the tertiary amine in an amount from about 0.5 to about 8 percent by weight; and combining the additive composition with the transmission fluid.