2004 Mercedes CL-Class Owner's Manual - Page 377

Technical data Fuels, coolants, lubricants, etc. Gasoline additives A major concern among engine manufacturers is carbon build-up caused by gasoline. Mercedes-Benz recommends only the use of quality gasoline containing additives that prevent the build-up of carbon deposits. After an extended period of using fuels without such additives, carbon deposits can build up especially on the intake valves and in the combustion area, leading to engine performance problems such as: Warm-up hesitation Unstable idle Knocking/pinging Misfire Power loss Do not blend any specific fuel additives with fuel. This only results in unnecessary costs and may be harmful to the engine operation. Damage or malfunctions resulting from poor fuel quality or from blending specific fuel additives are not covered by the Mercedes-Benz Limited Warranty. Coolants The engine coolant is a mixture of water and anticorrosion/antifreeze, which provides: Corrosion protection Freeze protection Boiling protection (by increasing the boiling point) The cooling system was filled at the factory with a coolant providing freeze protection to approximately -22°F (-30°C) and corrosion protection. If the antifreeze mixture is effective to -22°F (-30°C), the boiling point of the coolant in the pressurized cooling system is reached at approximately 266°F (130°C). The coolant solution must be used year round to provide the necessary corrosion protection and increase in the boil-over protection. Refer to Service Booklet for replacement interval. 376