What Is Antifreeze and What Does It Do?

What is antifreeze? Put simply, antifreeze, also called coolant, is the lifeblood of your vehicle during cold winter and hot summer months. If you do not have antifreeze in your vehicle when temperatures drop, you may find yourself stranded somewhere you would rather not be. Your vehicle also may fail to start altogether. Both of these situations also happen because of overheated engines.

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Understanding Antifreeze

The most common types of antifreeze are a combination of water and either ethylene glycol or polyproline glycol. Unless you are a chemist, the chemical makeup of antifreeze may not interest you much. Instead, you need to know the purpose of antifreeze. So, what does antifreeze do?

In simple terms, antifreeze circulates through your vehicle’s engine to maintain the temperature of important components. Most importantly, antifreeze keeps the temperature of your vehicle’s engine from dropping to a level that makes it difficult for the engine to do its job. That is, antifreeze prevents the engine from cooling off to a point where it may sustain significant damage. It also stops your car’s engine from overheating. Because an overheated engine can crack, having a steady supply of high-quality antifreeze coursing through the engine is vital for the overall health of your car, truck or SUV.

Antifreeze comes in a variety of colors, as manufacturers dye their products different shades. There is no distinguishable difference between neon green, pink, or orange coolant. Still, some recipes may use organic compounds that may appeal to you. Regardless of the color of antifreeze you choose, you should realize that coolant can be toxic to humans and pets. Therefore, you should not allow children, dogs or cats to drink spilled antifreeze.

Using Antifreeze

Your car has a radiator that is likely located in front of its engine. Antifreeze fills the radiator to facilitate cooling. Of course, because the radiator can reach temperatures that can easily burn human skin, the radiator also has an antifreeze or coolant reservoir. When antifreeze levels are low, you can pour coolant into the reservoir without worrying about hot liquid or steam burning you.

Antifreeze travels through your vehicle’s radiator and engine in a circular fashion, powered by the water pump. Coolant starts in the radiator before moving into the engine. There, it takes on heat that your car’s internal combustion engine naturally creates. After leaving the engine, antifreeze moves past your vehicle’s heating core. The heating core is responsible for keeping your car’s passenger cabin warm when temperatures drop. After picking up heat from the engine and heating the core, antifreeze moves back into the radiator. There, heat disperses before the cycle begins again.

Differentiating Between Water and Antifreeze

As mentioned, your vehicle’s water pump circulates coolant throughout its engine cooling system. While you know that the pump moves antifreeze, you may also wonder if water would work equally as well. The simple answer is no.

When temperatures are moderate, water is probably sufficient to cool your vehicle’s engine. Still, water may corrode sensitive parts of your vehicle. Adding anti-corrosive elements to water does the trick on ordinary days. Nonetheless, when temperatures climb or drop significantly, water does not have the ability to keep your vehicle’s engine at the appropriate temperature. As such, while water may work in a pinch, antifreeze is necessary for the long-term survival of your vehicle’s essential systems.

Why does antifreeze do a better job than ordinary water? The chemical formula of antifreeze both lowers its freezing temperature and raises its boiling temperature. As such, when ambient temperatures drop below freezing, antifreeze prevents cold weather from damaging your vehicle’s engine. Further, when your vehicle warms up due to either normal functionality or high outside temperatures, antifreeze keeps internal engine temperatures under control.

Replacing Degraded antifreeze

Your vehicle’s engine uses motor oil for lubrication. Still, engine oil does not last forever. In fact, your vehicle’s operator’s manual probably recommends changing motor oil every few hundred miles, as oil degrades over time. The same is true for antifreeze.

The ethylene glycol or polyproline glycol in most antifreeze blends does not degrade over time. Still, antifreeze has anti-corrosion compounds that break down with ordinary usage. These compounds protect the metallic components in your vehicle’s radiator, engine, and other systems from rusting. If you do not occasionally replace antifreeze, sensitive parts of your vehicle may corrode.

Knowing when to replace coolant is not difficult. Unlike brake fluid and even engine oil, which may retain its appearance over time, coolant changes color as it breaks down. If your antifreeze takes on a rust-colored or brownish hue, it is likely time to flush it out of your radiator and replace it with a fresh supply.

Adding New Antifreeze

If you need to replace your vehicle’s supply of antifreeze or top off the reservoir, you should first read through your owner’s manual. As usual, following manufacturer recommendation is an effective way to achieve success when replacing or adding antifreeze. You should remember a few things about this fluid, though.

First, you should note that antifreeze usually comes undiluted. With most vehicles, undiluted antifreeze is not compatible. Instead, you must mix the antifreeze with distilled water before adding it to the radiator. A 50-50 mixture of antifreeze and distilled water is typically correct. Still, it is possible to buy premixed antifreeze. If you go this route, you do not want to dilute antifreeze before adding it.

When mixing antifreeze and distilled water, you also must think about where you drive your vehicle. If you keep your car in a place that has temperatures that consistently fall below 34 degrees, you likely want to have a higher percentage of antifreeze than distilled water in your radiator. Generally, a 60-40 or even 70-30 ratio is appropriate.

Staying Ahead of Vehicle Maintenance

Like most machines, your vehicle needs regular maintenance to run optimally. Paying attention to antifreeze quantity and quality is essential. Now that you understand what is antifreeze, you are ready to work on your vehicle. Choose the right tools, fluids, filters and other items and get started on your project. You can get the parts you need at your local AutoZone Store. If the job is too big for you, seek out one of our Preferred Shops to help you do the job.

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