In the latest MXA, it was stated the Kayaba 01, Showa SS-7,and Pro Circuit PC-01 oils are all PRODUCED by the same company and are all 5 wt. They are identical w/ the exception of color. I recall one person saying Kayaba 01 is 1 wt oil. The article also states you should go no lighter than 5 wt for the lubrication abilities of the oil. I am presently using 2.5 wt PJ-1 hoping to make my forks more fluid. I guess I am all hosed. ------------------ '99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, OEM YZ tank, IMS YZ seat.