Almost two-thirds of all engine failures can be attributed to cooling system problems. Today as well, new engine designs for improved fuel efficiency and lower emissions have raised operating temperatures and pressures, adding to the demands on the cooling systems.

The proper antifreeze is vital to engine operation and protection. Advanced coolants are formulated for corrosion and scale build-up prevention, high-temperature stability and heat transfer, protection from freezing, and compatibility with hard water and plastics.

Recommended engine coolant

Most modern manufacturers recommend glycol-based antifreeze coolant. You will need to mix the glycol-based antifreeze with a certain amount of water because just the glycol-based antifreeze alone is not enough. Traditionally, freeze protection and heat transfer have been provided by a mixture of water and ethylene glycol in a recommended concentration of 40% to 60% by volume or 50/50.

More recently, propylene glycol has been introduced as a less toxic alternative to ethylene glycol. Developments have also led to the introduction of Organic Acid Technology (OAT) coolants because the corrosion inhibitors in OAT products last longer than those in traditional antifreeze.

For new vehicles, manufacturers choose effective coolant based on engine design. National standards such as ASTM D 3306, 4985, and 6210 and TMC RP 362 and 365 are used as minimum specifications. Vehicle OEMs and coolant manufacturers, such as Champion, Ford, Fleetguard, Heritage, Cummins, Volvo and Mack, Navistar, Penray, Prestone, OWI, Caterpillar, Valvoline, WIX, Navy, US Coast Guard, Donaldson, and others have their own specifications, and many also have private label products.

When coolant fluid levels are low, it is recommended that refills are made with formulations with the same specifications to avoid compatibility issues, and so the warranty is not affected.

In addition, even beyond the warranty period, it is still advisable to follow the vehicle manufacturer’s coolant recommendation. While vehicle cooling systems are under pressure and designed to be sealed and leak-free under normal circumstances, monitoring coolant levels during inspections and routine preventive maintenance can help detect leaks and address problems before they lead to costly repairs.

These include defective or deteriorated seals, blown head gaskets and improperly torqued head bolts, warped or cracked cylinder heads, cracked blocks or cylinder heads, corrosion damage to cylinder liners, and thermostat and water pump failures.

Most vehicle and coolant manufacturers recommend the use of test strips during coolant system inspections and maintenance. Acustrip provides a variety of coolant test strips that can be used during routine service to help ensure that coolant is adequately protecting cooling systems.