| abstract |
An additive package is disclosed for preparing an automotive crankcase lubricating oil composition for an internal combustion engine. The additive package is made by admixing:n (i) 50 mass % or less of an oil of lubricating viscosity; (ii) 50 mass % or less of at least one overbased metal detergent, preferably at least one overbased metal hydroxybenzoate detergent; (iii) 50 mass % or less of an oil-soluble block or graft co-polymer of at to least one polymeric block A which is derived from a hydroxycarboxylic acid and at least one polyalkylene block B which is a residue of a polyalkylene glycol, and (iv) optionally, at least one further additive selected from a dispersant, an antioxidant and/or an antiwear agent. nn The additive package includes less than 2.00 mass % preferably less than 1.50 mass %, of a friction modifier which is a monoester of a C 5 to C 30 carboxylic acid and which is free of nitrogen. n Component (ii) is preferably an overbased metal hydroxybenzoate detergent. n Component (iii) acts as a friction modifier and can be used as a replacement for a friction modifier such as glycerol monooleate. n The additive package exhibits improved stability. |