BMW oils...
LL-1 = USA/North American market =
high sulfur fuels.
LL-4 = Germany/EU market =
low sulfur fuels.
You want to use the correct oil (LL-rating) because the Nikasil coatings in the cylinderwalls (and piston rings) can wear when you use the wrong rated oils. This is why I (pay more) and use an LL-4 rated oil in my US Spec 135i that I feed it German low sulfur fuel.
This is what the BMW oil looks like sold at German BMW Zentrums (dealers). This oil sells for 22 to 33 euros PER liter at the dealership. You can find it online in Germany for as little as 6 euros though.
Here are the three oils that most dealers stock. Normal NA engine oil, LL-4 full synthtic oil (like what you need for a N54/N55 engine) and the Castrol TWS (S65 M3) oil...
This is what the German made Castrol oil (Castrol RS Edge, LL-4 0w40, 5L jug)looks like sold at many parts stores and grocery stores over here. The price varies from 70 to 110 euros for a five liter jug. You can find teh same oil online for as little as 40 euros for 5L's.
The older 5L bottle...
And now castrol has replaced the Castrol RS Edge oil with thier new Cstrol Edge FST oil.
The Castrol LL-4 rated oils (only two grades are: 0w40 and 5w40(I think) meet BMW specs. They also have these specs: ACEA B4 , BMW LL 04 , ACEA C3 , ACEA A3, and an API of SM.
Dackel