See also:

Premium-grade unleaded gasoline
To ensure the longevity and full performance of the engine, only premiumgrade unleaded gasoline must be used. If no premium-grade unleaded gasoline is available and regular unleaded gasoline mu ...

Cleaning the steering wheel and gear or selector lever
  Thoroughly wipe with a damp cloth or use leather care agents that have been recommended and approved by Mercedes- Benz. ...

Additives
Do not use any additives in the engine oil. This could damage the engine. ...