I have a question about rear diff service.
 

Ok, so i'm going to be doing a rear diff service on my 1996 318ti, it has a rear lsd diff, now the bmw dealer told me to run 75w-90 synthetic, when i asked them about additive they said that none is needed, is that right? every lsd i have ever seen has had some type of friction modifier. what do u guys think?

I know mine needed a special oil for the LSD, I'd go to bavauto.com and pick up the Redline synthetic fluid for LSD, you have to change it so rarely that you might as well splurge a little ;)