Processes to produce poly alpha-olefins

A process to produce a poly alpha-olefin (PAO) composition, the process comprising:

• introducing a first C6-C32 alpha-olefin, a second C6-C32 alpha-olefin different than the first C6-C32 alpha-olefin, and a first catalyst system comprising an activator and a metallocene compound into a first reactor under reactor conditions, wherein a molar ratio of the first C6-C32 alpha-olefin to the second C6-C32 alpha-olefin is from about 1:5 to about 5:1, by total moles of the first and second C6-C32 alpha-olefin;
• obtaining a first effluent comprising a PAO dimer;
• introducing the first effluent, a third C6-C32 alpha-olefin, and a second catalyst system to an oligomerization unit, wherein the third C6-C32 alpha-olefin includes octene;
• obtaining a second effluent;
• and
• hydrogenating the second effluent to form the PAO composition that is about 85 wt % or greater of a PAO trimer, wherein the PAO trimer comprises C24 to C36 trimer and an average trimer size of the PAO trimer is C31, and about 1 wt % to about 15 wt % of a C38+ PAO, and the PAO composition has a kinematic viscosity at 100° C. of from about 3.8 cSt to about 4.3 cSt, according to ASTM D445 and a polydispersity index of about less than about 1.02.