I don't understand BMW philosophy behind different types of grease for INNER and OUTER.

In the Volvo world and in other BMW (non-X5) models, the CV joints are made by GKN-Lobro and it is the type of grease for both INNER and OUTER CV Joints.

I personally think this is overkill, over-engineered non-sense. You are likely fine with the same grease. Anyway, I may be wrong...

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1998 E39 528i 5sp MT
2006 E53 X5 3.0 6sp MT