IIRC, the SVG already has some FM in it. They do, however, note that more may be necessary. But that is ONLY if you experience some form of objectional performance.
"
AMSOIL Severe Gear is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip Lock® friction modifier additive."
Additionally, here is a note from Amsoil on their fluid in regard to GM "grape juice" diff fluid (spec 9986115)
http://www.amsoil.com/techservicesbullet...%20revision.pdf
You can see that they address the topic of FM already being present in the product, and only adding if chatter occurs.
Do you NEED more, or are you just presuming it to be so? What is your application? Are you having signs that the SVG is not working adequately, and more FM is the answer?
Point is this:
You should not be adding FM to any product until you test it, and see if you truly need more. Too much is just as bad, if not worse, than not having enough.
If you purchase a product that has no FM, and you need some, then by all means, add what is called for by the dosing amount.
But when you have a product that already has FM, NEVER add any until you test it by driving and noting the operational conditions, and then ONLY add FM if needed, in small doses at a time, testing along the way.
Make sense?
