The function of combustion engines in cars is to convert the energy created by thousands of minute explosions into motion. This process, however effective, has two distinct side effects—heat and waste. To deal with the waste, the modern automobile employs an elaborate emissions control system designed to reduce your car's impact on our environment. To manage the intense heat created by running your engine, a cooling system is used.
Left unchecked, the heat created by your engine under normal operation will result in overheating and, likely, complete engine failure in just minutes. Why? Because when metal gets hot, it also expands and, as the precision components inside your engine expand beyond normal tolerances, movement grinds to a very sudden and, often, destructive stop.
The cooling system regulates engine temperature by circulating coolant through the engine block, pulling heat away from the metal and out to the radiator where it is cooled by passing air. To accomplish this task, antifreeze/coolant is specifically designed to handle extreme temperatures without breaking down or boiling away.
In addition to its heat dispersing properties, antifreeze/coolant also protects against corrosion in the engine and cooling system. This protection is attained through the incorporation of various corrosion fighting additives in the coolant/antifreeze. These additives are depleted over time, however, making regular cooling system flushes an essential aspect of any automobile maintenance regimen. Without them, premature corrosion is likely, and with that comes the possibility of cooling system failure. Check your owner's manual for the recommended changing intervals.
The third and final function of this multi-tasking solution is to lubricate the water pump and engine seals while preventing freezing. Freeze protection is the result of the solution being properly diluted, and does not change throughout the useful service life unless additional liquid, such as water, is added to the system.
Green with Envy
Unlike the predominantly cast-iron engine cooling systems of the past, the systems found in newer cars incorporate the product of multiple fabrication approaches to effective cooling, all of which are highly sophisticated when compared to original, electric-green swallowing designs. These modern-day solutions combine elements of cast-iron, aluminum, copper, brass, solder, steel and many nonmetallics like nylon and silicone.
To better deal with these changes, the latest formulations in antifreeze/coolants are as diverse as they are colorful. The days of one-size-fits-all, electric-green fluid are gone, and the day of the made-to-order, model-specific coolant is here. These advanced mixtures come in a rainbow of colors, but color is no longer an indicator of their intended application. Serving to protect and cool our modern engines are three basic chemistries.
IAT, or Inorganic Additive Technology, is the traditional green coolant found in most older vehicles. This solution offers fast-acting corrosion protection, although the additives are quickly consumed, exposing the cooling system to possible corrosion problems if not changed regularly.
OAT, or Organic Acid Technology, is the formula found in DEX-COOL®, and is usually the antifreeze/coolant of choice for VW and many Japanese/Asian vehicles. This updated formula is engineered to offer long-life corrosion protection. The downside of OAT is it is not compatible with other types of coolant (IAT and HOAT). In fact, Ford, DaimlerChrysler and others say not to use this type of coolant in their newer models.
HOAT, or Hybrid Organic Acid Technology, is found in newer Ford, Chrysler and Mercedes vehicles. Using the very best aspects of both IAT and OAT, HOAT is a very protective, long-life coolant.
Perhaps one of the most important aspects to look for when next shopping for antifreeze/coolant is approval from the maker of your car. Currently, there is no "one size fits all" solution that is approved for use in newer cars. And filling your cooling system with the wrong solution may result in serious adverse effects.
Products marked APPROVED have been subjected to years of field and lab testing by your car's manufacturer and are certain to provide the best performance and protection. Also, use of these products will ensure your car's warranty remains intact. The same cannot be said for using non-approved products, which may end up causing more problems than they solve. Some quality antifreeze/coolant producers even print the makes that have approved their products for use. This is always the best way to go.
As a car owner in today's fast-paced world, there are really only two key things to know when it comes to your car's antifreeze: Drain and replace it according to the manufacturer's recommendations (usually found in the owner's manual). And use an antifreeze/coolant that is approved by your manufacturer for use in your car. You-and your car-will be happier and more confident regarding the long-term integrity of your vehicle's essential cooling system.