2006 Mercedes R-Class Owner's Manual - Page 526

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 In areas where carbon deposits may be encountered due to lack of availability of gasolines which contain these additives, Mercedes-Benz recommends the use of additives approved by us for use on Mercedes-Benz vehicles. Refer to Factory Approved Service Products pamphlet for a listing of approved product(s). Follow directions on product label. Do not blend other specific fuel additives with fuel. This only results in unnecessary costs and may be harmful to the engine operation. Damage or malfunction resulting from poor fuel quality or from blending additional fuel additives other than those tested and approved by us for use on Mercedes-Benz vehicles listed in the Factory Approved Service Products pamphlet 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 -35°F (-37°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). 525