Yes but that has nothing to do with the quality of the oil, but the fact that the two have a commercial agreement including supply of oils to the F1 team, and other forms of motorsport. As part of the F1 deal (originally with Williams BMW, and now with BMW Sauber) BMW changed its recommended oil to Castrol.

Personally I have no problem using Castrol, but if it was my own choice I'd be going with Mobil 1.

__________________
StumpyPete



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