Diesel engine oil requirements are considerably different than those of gasoline engines. DO NOT PUT A GASOLINE ENGINE OIL IN A DIESEL ENGINE!!

Mobil's diesel engine oils are branded as "Mobil Delvac". They're primary diesel engine oil is "Mobil Delvac 1 5W-40" which they also "re-brand" as "Mobil® 1 Truck & SUV" (I've looked at the specs on both and they are identical).

Your BMW manual will provide an oil recommendation (Castrol). As long as the Mobil oil has the same API (American Petroleum Institute) classification as the manual states you'll be OK. The API classification for both of the above Mobil oils is: API CI-4 PLUS/CI-4/CH-4/CG-4/CF-4/CF/SL/SJ