Patent ID: 7704930

Claim:
A method to improve piston cleanliness and coefficient of friction in an internal combustion engine comprising (a) obtaining a lubricating oil composition comprising a first calcium salicylate detergent having a TBN of over about 200, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, a second calcium salicylate detergent having a TBN between about 100 and 200, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, and a third calcium salicylate detergent having a TBN less than about 100, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, and any combination thereof, (b) lubricating the internal combustion engine, and (c) maintaining in the internal combustion engine a coefficient of friction less than 0.1 between 100 and 180° C. and a film cleanliness less than 10% between 100° C. and 180° C.