Either 5W-30 or 5W-40 is fine. There is a tradeoff between the two, in that the 40 gives more protection at very high ambients (mas caliente que Miami), but the wider viscosity range is achieved by using additives in the oil that are not as stable, so in general the narrower range will hold its viscosity better. That said, there is really very little difference at the ambients we are talking about.

If you were pulling a loaded trailer through Death Valley, the 5w-40 would matter more.

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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