Coolant Recommendations and Specifications C8.3 Commercial Marine and Ind [...] Page V-16 Section V - Maintenance Specifications Specifications Use a low-silicate antifreeze that meets ASTM4985 test (GM6038M specification) criteria. Concentration Antifreeze must be used in any climate for both freezing- and boiling-point protection. Cummins Inc. recommends a 50-percent concentration level (40- to 60-percent range) of ethylene glycol or propylene glycol in most climates. Antifreeze at 68-percent concentration provides the maximum freeze protection and must never be exceeded under any condition. Antifreeze protection decreases above 68 percent.
Concentration Testing Antifreeze concentration must be checked using a refractometer (such as Fleetguard® Part No. CC2800). "Floating- Ball"-type density testers or hydrometers are not accurate enough for use with heavy-duty diesel cooling systems. Coolant Change Recommendation The coolant must be drained and replaced every 2 years or 385,000 km [239,227 mi] to eliminate buildup of harmful chemicals. Ethylene Glycol Propylene Glycol 40% equals -23°C [-9°F] 40% equals -21°C [-6°F] 50% equals -37°C [-35°F] 50% equals -33°C [-27°F] 60% equals -54°C [-65°F] 60% equals -49°C [-56°F] 68% equals -71°C [-96°F] 68% equals -63°C [-81°F]