Nothing wrong with the Mobil 0W-40 you were using. The Total Quart you have is not the LL-04, so it is OK, but there is nothing better about it than the Mobil or Castrol Syntec, they all meet the same API-SM spec.

The 0W rating (viscosity) refers to how the oil behaves when it is cold, ie when it is resistant to flow. That is when you want a thin oil, to help lubricate the engine on startup. It has no effect on viscosity when the engine is at operating temperature.

The Lucas product reduces the quality of your oil, as it dilutes what are very good oils and changes them in ways that you or Lucas can't predict. I wouldn't use it, and BMW specifically recommends not to use oil additives in these engines.

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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