Oil brand

Mobil 1 is a good oil.

Use the weight recommended in the owners manual. I would change the oil every 3,000 miles for regular oil and every 5,000 fr synthetic.

Use the best you can afford... Mobil 1 is a good bet, also Castrol Synthetic works. Both are readily available. And use the Mann or Bosch or Hengst fleece filters. Avoid generic oil and Fram filters like the plague. I, however, differ from F_O_R in that I follow the built in schedule (nanny) that computes the schedule based on real world. MB engineered the car and the maint. software, so why not use it? My '09 E350 always come due close to the book schedule, so I trust it. Don't skimp on oil or filters and do things when they are called for, Simple, but very important