There are a wide variety of antifreezes out there today formulated to offer the safety of “long-life,” “extended” or “fill-for-life” protection.

Properly used, these mean substantial savings in preventative maintenance checks and reduced downtime.

These coolant mixes protect copper, solder, brass, steel, iron and aluminum components from corrosion, rust, cavitation and scale build-up.

Depending upon what brand and type of antifreeze you select, the color when mixed with water can vary between green, red, pink, or orange.

The various brands that don’t indicate the product is formulated for extended-life use requires more frequent testing than ones engineered to last longer.

The antifreeze container will indicate if its contents are a pre-diluted 50/50 mixture, meaning that it consists of 50 per cent water. They will also indicate that they are “nitrite” free.

Nitrite is the primary inhibitor from protecting wet-sleeve-liners from pitting or rusting, however other additives are also used for this purpose. Keep in mind that an ethylene-glycol (EG) brew will tend to be less costly than a propylene-glycol (PG) type. The EG mixture has been used for many years and still satisfies most regular truck requirements.

Your owner’s manual will identify which type of antifreeze will comply with the specific recommendations and approval categories listed by the engine/vehicle manufacturer. The spec’s are generally approved by the American Society for Testing and Materials (ASTM).

Extended-life coolants are used in conjunction with slow, or “need-release,” coolant filters. They deliver supplemental coolant additives (SCAs), through a chemical reaction, into the coolant as additives are depleted over time.

These products typically need neither precharging when installed, nor recharging – for up to either 300,000 miles or 6,000 hours of off-highway use.

Fill-for-life antifreezes employ a fully-formulated coolant, which meets the heavy-duty truck specifications for phosphate-free emissions.

This type of coolant can be used, generally, for up to 500,000 miles, since it employs a need-release coolant filter with SCAs, to automatically maintain the engine coolant at optimum levels.

The filter is rated for 100,000 miles, or one year of service, when used with low-phosphate, low-silicate antifreeze. Its service can be extended to more than 120,000 miles, when using phosphate-free antifreeze (look for the spec TMC RP-329/330).

Typical antifreezes which meeting the TMC RP329/330 code includes Caterpillar Diesel Engine antifreeze /coolant; Detroit Diesel Power Cool; Cummins Fleetcharge; Quaker State antifreeze; MacGuard 2792; Prestone Heavy Duty; and Sierra (PG antifreeze).

Customers are encouraged to adopt TMC RP-329 and RP-330 specs for new coolant purchases. This recommendation also applies to all vehicles – light-, medium- and heavy-duty; and all fuels – gasoline, diesel or gaseous.

For heavy-duty diesel trucks, the two dominant technologies for SCAs are Pencool 3000 and Fleetguard DCA-4. Pencool technology is used by both Caterpillar and Detroit Diesel, while DCA-4 is the SCA used by Cummins, which owns Fleetguard.

Some antifreeze, extended-life coolant systems, in PG brands, such as Texaco, contain a carboxylate inhibitor technology. This is a formulation that is free of nitrate, borate, phosphate, silicate, and amine.

It provides maximum protection for the the six basic metal alloys found in most heat-transfer systems.

With no phosphates or silicates, hard water deposits in the coolant are reduced and water-pump seal wear is reduced as a result of fewer abrasive, dissolved solids.

One more thing. Always be sure to read the data sheets available for each specific make or type of antifreeze.

Compare that data with the engine- or vehicle- manufacturer specifications. Pay particular attention to the product description, features application and approvals, and product maintenance, coolant contamination, and handling practices.

– Bob Brady is the president of Hitech consulting in Burnaby, B.C.