Abstract: A polyalkene dispersant comprised of low MW polyalkene having an average molecular weight range of about 300 to about 10,000 and an ethylenically-unsaturated, aliphatic or aromatic, nitrogen- and oxygen-containing graftable monomer and methods of making the same are disclosed. The monomers are formed by reacting an acylating agent with amines having one or more primary or secondary amine to form a reaction product. Graft polyalkene dispersants comprising such monomers are formed by grafting the reaction product to the polyalkene backbone. Also described is lubricating oil comprising base oil and the dispersant polyalkene as described above.

Abstract: Soot in a lubricated diesel engine is effectively dispersed without adversely affecting the viscosity of the lubricant by using a particular lubricant. The lubricant utilized comprises a lubricant base stock (e.g. more than 75% by weight), a dispersant (e.g. from 0.2-less than 4% from a detergent inhibitor (D1) package), and a functionalized viscosity index improver (e.g. from 0.1-2.5% by solids weight). The functionalized viscosity index improver is a highly functionalized graft copolymer reaction product of an oxygen, a nitrogen, or an oxygen and nitrogen containing, ethylenically unsaturated, aliphatic or aromatic monomer having from 2 to about 50 carbon atoms grafted onto a polyolefin copolymer. Also, 0-2.5% by solids weight of another viscosity index improver besides the highly functionalized graft copolymer reaction product may be added, as well as other conventional additives.