Disclosed herein are oligomerization processes using feedstocks containing 1-hexene to produce an oligomer product, and methods for recovering a heavy 1-hexene oligomer from the oligomer product and hydrogenating the heavy 1-hexene oligomer. The resultant hydrogenated heavy 1-hexene oligomer can be blended with other PAO's to form 100 cSt and 40 cSt lubricant compositions, which have viscosity index and pour point properties that are equivalent to or better than respective 100 cSt and 40 cSt 1-decene PAO's.