2008 Mercedes CLS-Class Owner's Manual - Page 454

Technical data Fuels, coolants, lubricants etc. If the antifreeze mixture is effective to -35°F (-37°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. For information on other Mercedes-Benz approved products of equal specification, refer to the Factory Approved Service Products pamphlet (USA only) or contact an authorized Mercedes-Benz Center. To provide important corrosion protection, the solution must be at least 50% anticorrosion/antifreeze (equivalent to freeze protection to approximately -35°F [-37°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 an authorized Mercedes-Benz Center. 453