Originally Posted by pizzaguy

THe current recommendation is Mobile 1 5W40. In the heat of the south, I run 5W40 these days in the winter and 5W50 in the summer. (Well, I DID, when my car was a daily driver. Not sure what I'll do now, the new one is garaged most of the time.)

Every oil approved is right here:

MB 229.3 - Multigrade engine oils (Specification 229.3) - Mercedes-Benz Specifications for Operating Fluids

Many guys run Royal Purple, I think some here have more than 50,000 miles on their car with no issues using it. We are long past the warranty period, so that is one reason that you can wander from the recommendations.