This is for my 2000 Camaro with stock Torsen differential, which does *not* require any limited slip additive. I purchased some Valvoline 85W140 semi-synthetic. This will be my 4th attempt to quiet down the well-known noise that these diffs make under certain conditions. (First tried Supertech 75W140, then added moly, then added GM LS additive because someone said that would fix it, nothing's worked so far.) Now before I pour the Valvoline in, I'm doubtful, since on the back of the bottle is says "for limited slip differentials, top-up only". Is this just because this fluid does not contain any LS additive? (I assume it doesn't, since no mention on the bottle.) The Torsen doesn't have any clutches, hence why it doesn't use additive. Would there be any other reason for this warning?