| 摘要 |
The invention relates to a method of lubricating an internal combustion engine comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, 2.3 wt % to 4 wt % of a dispersant package, wherein the dispersant package comprises: a borated succinimide dispersant obtainable by an "ene" reaction of a polyalkylene with an acylating agent to form an intermediate, reacting the intermediate with an aminoalcohol or amine to form a dispersant, and reacting the dispersant with a borating agent to form a borated succinimide dispersant; and a non-borated succinimide dispersant obtained by a "Diels-Alder" reaction. The ratio of non-borated succinimide dispersant to borated succinimide dispersant is 90:10 to 20:80, and the borated succinimide has 0.2 wt % to 1.3 wt % boron on an oil-free basis of the dispersant. |
