Most people’s knowledge of antifreeze is that it is a weird, bright-colored liquid, which looks more like a citrus-flavored beverage than an engine additive. But what does it actually do? And why do you have to add water to it?
What Is Antifreeze?
Antifreeze, otherwise known as coolant, is primarily made up of ethylene or propylene glycol. These compounds work to reduce the freezing point of liquids, thus preventing freezing in the winter. But, it also acts as your engine's coolant during the summer, since it stands up well to high temperatures. Additionally, most coolants on the market contain rust-inhibiting compounds to keep coolant passages rust free.
Why It's Important
Given this information, it's pretty easy to understand why antifreeze is important. But, what exactly are the consequences of extreme engine temperatures?
If an engine gets too cold, then the coolant can actually freeze within its parts and eventually crack them. The main victims are the radiator and the engine block. A cracked radiator will leak coolant, requiring constant (and often roadside) replacement and will insufficiently maintain engine temperatures.
An engine that gets too hot, on the other hand, will experience severe damage. As temperatures reach extreme highs, thermal expansion damages and weakens various parts of the engine, including pistons, cylinders, and seals. High temperatures will also alter the physical property of the engine oil, thus causing improper lubrication and, subsequently, damage to a wide range of engine parts that require proper lubrication.
Although you probably won't completely destroy an engine if it overheats only one time, exposing your car's engine to high temperatures over long periods of time will eventually ruin it.
It's always a good idea to spend some money to replace car parts before they cause more expensive problems. With antifreeze, however, you're looking at a very small investment ($10–$50), which could end up saving you the cost of a new engine. When it comes to engine coolant, there's no room for laziness or frugality.