Rear Diff Oil 75W-140 question

[E.K]

I was initially looking for Castrol Syntrax 75W-140 but couldn't find any in a short period but i need rear diff oil soon for my E92 M3. Then i found the REDLINE 75-140NS (Non slip) and a separate add on friction modifier. Has anyone been using this combination or seen any? Please do advise. Thanks

[Scharbag]

I have not used this combo. Redline does sell a 75W140 that works in the M3.

[dparm]

Should be fine if you are planning to add the LS stuff to suit your taste. But why not just get it pre-mixed? Do you feel like their regular 75w140 has too much LS additive?

I would also recommend calling Red Line tech support directly and talking to them, they're smart people who could help understand your needs and recommend a product.