GM crap
The stuff you are talking about is for use in differentials with limited slip or posi traction. This stuff is used to lubricate the clutch material in the said unit. Some of GM`s transfer cases also have clutches inside so they use it there as well. I believe, but not 100%, that Toyota uses cone style for there limited slip so there isn`t any clutches. If you don`t have limited slip you don`t need this additive at all. If you do have a limited slip differential check with someone who knows what kind of limited slip you have. Limited slip will allow both tires to spin at the same time when power is transfered through the differential and allow one tire to spin at a different speed when little or no power is going through the differential, like when you go around a corner.
