This SAE Information Report is a source of information concerning the basic properties of engine coolants which are satisfactory for use in internal combustion engines. Engine coolant concentrate (antifreeze) must provide adequate corrosion protection, lower the freezing point, and raise the boiling point of the engine coolant. For additional information on engine coolants see ASTM D 3306 and ASTM D 4985. The values presented describe desirable basic properties. The results from laboratory tests are not conclusive, and it should be recognized that the final selection of satisfactory coolants can be proven only after a series of performance tests in vehicles. The main body of this document also describes in general the necessary maintenance procedures for all engine coolants to insure proper performance. In addition, special requirements for coolants for heavy-duty engines are covered in Appendix A. This document does not cover maintenance of engine cooling system component parts.