About Radiator Fluid

After getting early automotive engines running, there was a need to devise a way to cool them. Radiator fluid was the answer. From reformulating to accommodate aluminum engines to adjusting to higher engine temperatures, coolant/antifreeze has had to adapt to an ever-changing automotive environment.

History

With the exception of first generation VW Beetles, most cars are water-cooled. The internal combustion engine, as the name implies, produces heat. So the early automotive engineers faced a hurdle: control the heat naturally produced by the engine or face certain heat-induced seizure of moving parts. But concern was not limited to heat stress--engines had to be protected from freezing up in the winter. Untreated water in the cooling system expands when frozen, causing cracked engine blocks and frozen radiators. The answer to untreated radiator fluid was antifreeze/coolant.

Types

Ethylene glycol, which is the base for most coolants, is clear in color and can't be distinguished from water . For marketing and ease of identification, dyes are added. Until the mid 1990s, coolant manufactured for American cars was exclusively green, while European cars used Organic Acid Technology (OAT) in their formula. This was orange or red, which became the color of the General Motors product Dex-Cool. Propylene Glycol is an alternative base and is preferred in some circles because of its decreased toxicity as compared to ethylene glycol, which allows it to be used more confidently around animals and children.

Function

The main job of all antifreeze/coolants is protection from overheating and freezing. The product raises the boiling point of the fluid traveling around the cooling system and also lowers the freeze point. During the production process, additives are blended with the base fluids to prevent foaming and inhibit corrosion. Coolant is then diluted with water (distilled water extends coolant life). Early editions of coolant were designed to be drained every other year or 30,000 miles, but later versions were good for 5 years or 150,000 miles.

Significance

Refining the formulation of antifreeze/coolant made a profound difference in the automobile industry. The most obvious result of the use of coolant as opposed to water was the ability to produce engines that ran hotter. It allowed for bigger pay loads and larger occupant capacity. The ability to travel long distances through various climate conditions was only achievable through the utilization of coolant.

Considerations

The advent of more sophisticated engines has made the selection of radiator fluid a complicated process. Unfortunately, it is not just a matter of matching the color of the coolant. There is OAT and IAT, depending on whether ii is organic or inorganic. And there's LLC or ELC, which distinguishes Long Life from Extended Life Coolant. Applications have to be checked against industry or engine specifications.