This study attempted to synthesize and characterize engine oil additives from plastic waste, i.e., low density polyethylene, high density polyethylene, and poly propylene for the purpose of improving the viscosity index and pour point of engine oils. To do this, the starting polymers were reacted with maleic anhydride in a chain growth addition polymerization. The reactions took place in a muffle furnace at 230 degrees C. The product poly (alkenymaleic anhydride) was then reacted with a glycerol at 140 degrees C in a step growth addition polyesterification in the presence of xylene and nitrogen. The product formed, i.e., monoester acid, was then reacted with diethylene triamine in a step growth condensation polyamidation to produce the additive. The results obtained showed that the utilization of the additive produced from poly propylene as an additive on the base oils, i.e., SN150, SN500, BS 150 and commercially available oil (YT3513), gave the best results. The optimum blending concentration of 60 g/dl was achieved for the base oils except BS 150, which was 50 g/dl. Results also indicated that the optimum weight percentage of the blended additives was 3 wt%, while the optimum viscosity index was 162, 160, 159, and 186 corresponding to an increment of 80, 64.42, 36.76, and 36. 76% for SN150, SN500, BS150, and YT3513, respectively.