Automatic transmission fluids having enhanced performance capabilities
AssigneeEthyl Corporation
InventorsSanjay Srinivasan, David Warren Smith, John P. Sunne
Life of this patent
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Abstract
Automatic transmission fluids are described which contain a dispersant having a nitrogen to phosphorus mass ratio between about 3:1 and about 10:1, and at least one friction modifier. The use of dispersants having a nitrogen to phosphorus mass ratio between about 3:1 and about 10:1 provides automatic transmission fluids which exhibit good anti-shudder properties as well as a higher mid-point torque, a higher static torque in shifting clutch applications and better frictional durability as compared to similar automatic transmission fluids which contain dispersants having a nitrogen to phosphorus mass ratio of less than 3:1.
Claims24
An automatic transmission fluid composition, which exhibits good anti-shudder properties, comprising (1) a major amount of a base oil and (2) a minor amount of an additive composition comprising:
- (A) a dispersant having a total nitrogen to phosphorus mass ratio between about 3:1 and about 10:1;
- and
- (B) at least one friction modifier.
An automatic transmission fluid composition, which exhibits good anti-shudder properties, obtained by combining (1) a major amount of a base oil and (2) a minor amount of an additive composition comprising:
- (A) a dispersant having a total nitrogen to phosphorus mass ratio between about 3:1 and about 10:1;
- and
- (B) at least one friction modifier.
Dependencies are inferred from the claim text.