An olefin copolymer viscosity modifier comprising the reaction product of a) an acylated olefin copolymer which is an olefin copolymer having grafted thereon, with the aid of a free-radical initiator either in solution or in bulk, from 0.10 to 0.80 acyl groups per 1,000 number average molecular weight units of olefin copolymer and wherein the olefin copolymer is an ethylene copolymer or terpolymer and has a number average molecular weight of between 3000 and 100,000; b) a polyamine compound of Formula I: and c) a dicarboxylic acid or anhydride thereof, which reacts with a free primary amine of Formula I to produce a ring moiety A wherein ring moiety A is a 5, 6, or 7 membered heterocyclic ring having up to three rings fused thereon, wherein the ring or rings fused thereon are selected from phenyl, carbocyclic, heterocyclic, heteroaryl, or combinations thereof, and wherein ring A is optionally substituted with one or more substituents selected from halo, -CN, oxo, hydroxyl, haloalkyl, C 1-4 alkyl, C 1-4 alkylcarbonyl, C 1-4 alkoxy, C 1-4 alkoxycarbonyl, -NH 2, -NH(C 1-4 alkyl), and N(C 1-4 alkyl) 2; X is a C 2 to C 50 alkylene linker unit wherein one or more carbon units are optionally and independently replaced with a bivalent moiety selected from the group consisting of -O-, -NR'-, -NR'NR'-, -C -, -C O-, -C NR', and wherein each X is optionally and independently substituted with one or more R" substituents; each R' is selected from the group consisting of hydrogen, C 1-6 aliphatic, phenyl, or alkylphenyl; and each R" is independently selected from the group consisting of C 1-6 aliphatic, C 3-7 cycloalkyl, a 3-7 membered heterocycloalkyl, heteroaryl, and phenyl, wherein R" is optionally substituted with halo, cyano, amino, hydroxyl, -OR', -C R', -C OR', or - C NR' 2. a) an acylated olefin copolymer which is an olefin copolymer having grafted thereon, with the aid of a free-radical initiator either in solution or in bulk, from 0.10 to 0.80 acyl groups per 1,000 number average molecular weight units of olefin copolymer and wherein the olefin copolymer is an ethylene copolymer or terpolymer and has a number average molecular weight of between 3000 and 100,000; b) a polyamine compound of Formula I: and c) a dicarboxylic acid or anhydride thereof, which reacts with a free primary amine of Formula I to produce a ring moiety A wherein ring moiety A is a 5, 6, or 7 membered heterocyclic ring having up to three rings fused thereon, wherein the ring or rings fused thereon are selected from phenyl, carbocyclic, heterocyclic, heteroaryl, or combinations thereof, and wherein ring A is optionally substituted with one or more substituents selected from halo, -CN, oxo, hydroxyl, haloalkyl, C 1-4 alkyl, C 1-4 alkylcarbonyl, C 1-4 alkoxy, C 1-4 alkoxycarbonyl, -NH 2, -NH(C 1-4 alkyl), and N(C 1-4 alkyl) 2; X is a C 2 to C 50 alkylene linker unit wherein one or more carbon units are optionally and independently replaced with a bivalent moiety selected from the group consisting of -O-, -NR'-, -NR'NR'-, -C -, -C O-, -C NR', and wherein each X is optionally and independently substituted with one or more R" substituents; each R' is selected from the group consisting of hydrogen, C 1-6 aliphatic, phenyl, or alkylphenyl; and each R" is independently selected from the group consisting of C 1-6 aliphatic, C 3-7 cycloalkyl, a 3-7 membered heterocycloalkyl, heteroaryl, and phenyl, wherein R" is optionally substituted with halo, cyano, amino, hydroxyl, -OR', -C R', -C OR', or - C NR' 2. ring moiety A is a 5, 6, or 7 membered heterocyclic ring having up to three rings fused thereon, wherein the ring or rings fused thereon are selected from phenyl, carbocyclic, heterocyclic, heteroaryl, or combinations thereof, and wherein ring A is optionally substituted with one or more substituents selected from halo, -CN, oxo, hydroxyl, haloalkyl, C 1-4 alkyl, C 1-4 alkylcarbonyl, C 1-4 alkoxy, C 1-4 alkoxycarbonyl, -NH 2, -NH(C 1-4 alkyl), and N(C 1-4 alkyl) 2; X is a C 2 to C 50 alkylene linker unit wherein one or more carbon units are optionally and independently replaced with a bivalent moiety selected from the group consisting of -O-, -NR'-, -NR'NR'-, -C -, -C O-, -C NR', and wherein each X is optionally and independently substituted with one or more R" substituents; each R' is selected from the group consisting of hydrogen, C 1-6 aliphatic, phenyl, or alkylphenyl; and each R" is independently selected from the group consisting of C 1-6 aliphatic, C 3-7 cycloalkyl, a 3-7 membered heterocycloalkyl, heteroaryl, and phenyl, wherein R" is optionally substituted with halo, cyano, amino, hydroxyl, -OR', -C R', -C OR', or - C NR' 2.