Coolant Recommendations and Specifications C8.3 Commercial Marine and Ind [...] Page V-14 Section V - Maintenance Specifications Cummins, Inc. recommends using Fleetguard® Compleat. It is available in both glycol forms (ethylene and propylene) and complies with TMC standards. Fully formulated antifreeze must be mixed with high- quality water at a 50/50 ratio (40- to 60-percent working range). A 50/50 mixture of antifreeze and water has a -36°C [-33°F] freezing point and a 108°C [226°F] boiling point, which is adequate for North America. The actual lowest freezing point of ethylene glycol antifreeze is at 68 percent.
Using higher concentrations of antifreeze will raise the freezing point of the solution and increase the possibility of a silicate gel problem. Legend 1 Freezing Point Temperature Scale 2 Boiling Point Temperature Scale