What grade of oil does 1999 Mercedes E-320 use?

A 1999 Mercedes-Benz E320 requires 5W-30 engine oil. However, always check your owner's manual for the most precise and up-to-date recommendation. The manual will specify the type and grade of oil recommended by the manufacturer, which may include specifications beyond just the viscosity (like MB 229.1 or a later specification). Using the wrong oil can damage your engine.