LUBRICATING OIL COMPOSITIONS WITH ENGINE WEAR PROTECTION

摘要

A method for improving wear control, while maintaining or improving deposit control and fuel efficiency, in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one dispersant and a mixture of viscosity modifiers, as minor components. The at least one dispersant is a polyalkenyl succinic derivative and at least one viscosity modifier is a vinyl aromatic-containing polymer or copolymer. A lubricating engine oil having a composition including a lubricating oil base stock as a major component, at least one dispersant and a mixture of viscosity modifiers, as minor components. The lubricating engine oils are useful in internal combustion engines including direct injection, gasoline and diesel engines.

主权项

1. A method for improving wear control, while maintaining or improving deposit control and fuel efficiency, in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil, said formulated oil having a composition comprising a lubricating oil base stock as a major component; and at least one dispersant and a mixture of viscosity modifiers, as minor components; wherein at least one dispersant is a polyalkenyl succinic derivative and at least one viscosity modifier is a vinyl aromatic-containing polymer or copolymer having a weight average molecular weight greater than 80,000, and a number average molecular weight greater than 40,000; wherein the vinyl aromatic-containing polymer or copolymer has an amount of vinyl aromatic content greater than 10% by weight of the vinyl aromatic-containing polymer or copolymer; and wherein wear control is improved and deposit control and fuel efficiency are maintained or improved as compared to wear control, deposit control and fuel efficiency achieved using a lubricating engine oil containing minor components other than the at least one dispersant and the mixture of viscosity modifiers.