A low viscosity poly(alpha-olefin) (PAO) is produced by contacting one or more C3 to C24 alpha-olefins with an unbridged, substituted bis-cyclopentadienyl transition metal compound, a non-coordinating anion activator, and an alkyl-aluminum compound. The molar ratio of transition metal compound to activator is 10:1 to 0.1:1 and the molar ratio of alkyl aluminum compound to transition metal compound is 1:4 to 4000:1. The transition metal compound has either (a) at least one non-isoolefin substitution on both cyclopentadienyl rings, or (b) at least two substitutions on at least one cyclopentadienyl ring. The PAO is comprised of at least 50 mole % of C3 to C24 alpha-olefins, has a Mw/Mn between 1 and 1.4, and a kinematic viscosity at 100° C. of 20 cSt or less.