I have heard that if you have a limited slip diff that it requires an "extra" additive.
Have you heard of this?
Also, I spoke to the dealer and they told me that my car has a limited diff after I supplied them the serial number. However, I have heard that the LSD only came on e39 M5's. IS this true?
BTW...The Royal Purple feels just as lousy as the BMW LT-1 with respect to gear changes...I guess the guys on Bimmer fest were imagining a "noticable" improvement in shifts. I for one dont feel anything better..perhaps I have to give it more time.
Perhaps the only cool thing about Royal Purple is the color.