I don't think anyone can say for sure. BMW don't publish specifications on the fluid, so at best it would be a guess.

The non x-drive uses ATF fluid, which is essentially a 10W hydraulic oil. The x-drive has friction modifiers added in to it because of the clutch plates for the torque distribution system. What we don't know is if the base fluid is a similar viscosity to the non x-drive fluid. If it is, it would work fine. If it isn't, you risk damaging the transfer case.

I know what I would do personally (compare the viscosity of the two fluids and make a judgement call) but I won't advise you to do that because of the risk. one pint of ATF probably costs about $3, so maybe you should just buy a Dexron III fluid. Your call.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue