AAM was adiment on no liminted slip additive needed but I found Dealers,independents etc. that say they have had to use it. I talked to Amsoil tech assistance whom said read our labels"says in affect liminted slip additive MAY be needed in certain vehicles" I know I had a heck of a hot shudder towing and on left turns. Chased u/joints/center support bearing and driveline angles. Finally bought some additive at Auto Zone poued it in and withen 20 miles no shudder or turning left and hearing/feeling tires barking,grabbing.