What oil to use in 2005 Mercedes c230k?

Newer cars use 5w 30. However your vehicle uses a turbo charger which is very hard on oil, temp wise. I would use a synthetic 5w-30 oil. A little extra money now is better than alot of money later to repair the engine! I have a c230 and that is what i use. Mobil-1 or castrol syntec every 3000 miles.