Lubricating oil compositions with improved wear performance and soot dispersancy

Abstract

This invention relates to a diesel engine lubricating oil composition comprising or resulting from the admixing of: (i) base oil, (ii) a functionalized polymer, (iii) an overbased magnesium based detergent, (iv) an overbased calcium based detergent and (iv) one or more, optionally borated, higher and lower molecular weight PIBSA-PAM dispersants. The composition has a total sulfated ash of less than or equal to 1.0 wt. %, a kinematic viscosity at 100° C. of 5 to 20 cSt, a total phosphorous level of less than or equal to 0.120 wt. %, and a total sulfur level of less than or equal to 0.4 wt. % and provides a Cummins ISM oil filter delta pressure (OFDP) test result at 150 hours of less than 30 kPa. Also provided are a method of making the composition, a method of lubricating a diesel engine, a method of improving wear performance and soot dispersancy and reducing emissions of a diesel engine, and a diesel engine oil additive concentrate composition.