The present invention is a lubricant or functional fluid additive for a polyolefin oil blend, comprising a mixture of: (a) an anti-wear component consisting essentially of 95% isopropylated triarylphosphate and 5% dodecyl phosphate, the dodecyl phosphate being only partially esterified, the anti-wear component present in the polyolefin oil blend in a range of from about 0.75 percent to about 2.00 percent by weight; (b) an antioxidant component selected from the group consisting of alkylated phenyl-alpha-naphthylamine, phenyl-alpha-naphthylamine and mixtures thereof, and present in the polyolefin oil blend in a range of from about 0.75 percent to about 2.00 percent by weight; (c) an anti-rust component comprising an alkylated succinic acid ester anti-rust agent, and present in the polyolefin oil blend in a range of from about 0.050 percent to about 0.125 percent by weight; and (d) a metal deactivator component comprising a tolytriazole derivative, and present in the polyolefin oil blend in a range of from about 0.050 percent to about 0.125 percent by weight.