Is Anceaux XL synthetic engine oil?
This oil is fully synthetic and has a long-term series. It can range from 15000 to 20000 kilometers. However, 5w30 is not recommended for your Mercedes S300. I suggest you use Anceaux XL's 10w40. Actually, you might as well use Mobil No.1 0w40, 1 1000, which is a very good choice.