Lubricating oil additives and composition containing same

A lubricating composition comprising a major portion of a lubricating oil and an effective dispersing and viscosity improving amount of an additive having a thickening power at 210.degree. F in the range of 1.0 to 100 SUS and an infrared spectrum containing absorbance peaks at frequencies in the range of 1550-1750 cm-.sup.1. obtained by dissolving in an inert solvent from 10 to 100,000 parts by weight of a ethylene/propylene copolymer or terpolymer of an unsaturated hydrocarbon having a molecular weight of 5000 to 500,000 adding to the resulting solution a free radical iniator catalyst;

• bubbling air through the reaction medium to hydroperoxidize said copolymer or terpolymer;
• then adding from 100 to 100,000 parts of said lubricating oil;
• removing said inert solvent by vacuum distillation;
• adding 1 to 20 parts by weight of a di(lower)-alkylamino(lower)alkylamine containing both tertiary and primary amino nitrogen groups;
• heating the mixture for 0.5 hours to 20 hours at a temperature of 80-250.degree. C under a pressure of 0 to 1000 psig and distilling the reaction mass under vacuum at 80 to 300 degrees C to remove excess polyamine and initiator.