The present disclosure relates to oxazoline modified lubricant additives that have dispersant properties and lubricating oil compositions including such dispersant lubricant additives. The disclosure also relates to the use of lubricant compositions comprising the additives of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition while providing robust and consistent frictional performance at the same time.

A lubricating oil composition comprises a major amount of an oil of lubricating viscosity and a minor amount of an unsymmetrical bis-succinimide, or a mixture of unsymmetrical bis-succinimides, of the structure (I):

##STR00001##

wherein one of R.sub.1 and R.sub.2 is a polyisobutylene group having a weight average molecular weight of 400 to 5,000, as determined by GPC with reference to linear polystyrene standards, and the other of R.sub.1 and R.sub.2 is a hydrocarbon group made by the metallocene-catalysed polymerisation of an -olefin feedstock; and x is from 1 to 10 and is the same for all molecules of structure (I), or an average of all molecules of structure (I) in a mixture of molecules of structure (I).

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The present disclosure relates to lubricant additives such as dispersants and dispersant viscosity modifiers including acyl peptide grafted polymers and lubricating oil compositions comprising such additives. The disclosure also relates to the use of lubricant compositions comprising the additives herein for improving the soot or sludge handling characteristics of an engine lubricant composition and while minimizing the deterioration of engine's elastomer compatibility.

Use of a nitrogen-containing ashless dispersant in a lubricating composition for the purpose of reducing wear in the presence of ZDTP and soot wherein the nitrogen-containing ashless dispersant has a Functionality (F) of greater than 1.4.

Disclosed is a lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100 C. in a range of about 2 to about 50 mm.sup.2/s; (b) a hydrocarbyl succinimide dispersant; (c) a borated hydrocarbyl succinimide dispersant; and (d) a hydrocarbyl succinimide post-treated with a post-treating agent selected from the group consisting of an organic carbonate, an epoxide, a lactone, a hydroxyaliphatic carboxylic acid, and combinations thereof.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.