Lubricating oil compositions for hydrogen fueled engines for reduced pre-ignition

Abstract

This invention relates to a lubricating oil composition for a hydrogen fueled internal combustion engine (H2ICE) 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, and one or more zinc hydrocarbyl diphosphate compounds. 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 0.12 wt. %, and a total sulfur level of less than or equal to 0.4 wt. %. The composition provides a reduction in abnormal pre-ignition events during combustion in a H2ICE compared to a comparable composition not including the combination of the functionalized polymer, the higher molecular weight PIBSA-PAM, the lower molecular weight PIBSA-PAM, the overbased magnesium containing detergent, the overbased calcium containing detergent, and the one or more zinc hydrocarbyl diphosphate compounds. Also provided are a method of making the composition, a method of lubricating a hydrogen engine, a method of reducing abnormal combustion events in a H2ICE, and a hydrogen engine oil additive concentrate composition.