2006 Mercedes E-Class Owner's Manual - Page 491

Technical data Fuels, coolants, lubricants etc. 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 boil-over protection. Refer to Maintenance Booklet for replacement interval. Coolant system design and coolant used determine the replacement interval. The replacement interval published in the Maintenance Booklet is only applicable if MB 325.0 anticorrosion/antifreeze solution or other Mercedes-Benz approved products of equal specification (see Factory Approved Service Products pamphlet) are used to renew the coolant concentration or bring it back up to the proper level. To provide important corrosion protection, the solution must be at least 45% anticorrosion/antifreeze [equivalent to freeze protection to approximately - 22°F (-30°C)]. If you use a solution that is more than 55% anticorrosion/antifreeze [freeze protection to approximately - 49°F (-45°C)], the engine temperature will increase due to the lower heat transfer capability of the solution. Therefore, do not use more than this amount of anticorrosion/antifreeze. If the coolant level is low, water and MB 325.0 anticorrosion/antifreeze should be used to bring it up to the proper level (have cooling system checked for signs of leakage). Please make sure the mixture is in accordance with label instructions. The water in the cooling system must meet minimum requirements, which are usually satisfied by normal drinking water. If you are not sure about the water quality, consult your authorized Mercedes-Benz Center. Anticorrosion/antifreeze Your vehicle contains a number of aluminum parts. The use of aluminum components in motor vehicle engines necessitates that anticorrosion/antifreeze coolant used in such engines be specifically formulated to protect the aluminum parts. (Failure to use such anticorrosion/antifreeze coolant will result in a significantly shortened service life.) 490