Wanna change my rear end fliud, whats your input on royal purple? also I have the G80 option (limited slip) is there an additive I have to add to the royal purple? some one told me that they needed a special fluid so I dont know if the royal purple will work.

 

I put royal purple in not too long ago and it had friction modifier in it already , usually if it's got it in there they'll brag about it on the label of the bottle .

 

Heard that posi's or limited slips require an additive so wasnt sure if i needed to add it to the royal purple...I knew the RP had a friction modifier in it just wasnt sure if it was the factory suggested.