What is Antifreeze & What Does it Do: 5 Incredible Benefits

Antifreeze serves a crucial cooling function in vehicle engines. As the name suggests, it prevents engine coolant from freezing in cold temperatures. 

It also acts as a lubricant and protects against corrosion through chemical additives. This shields internal components from damage over time.

In this article, we’ll explore what does antifreeze do and how it regulates engine temperature and ensures regular heat transfer.

What is antifreeze?

Antifreeze is a fluid used in vehicle cooling systems to protect the freezing point of water. Its main purpose and function is to lower the freezing point of the engine’s coolant liquid.

Chemical Composition of antifreeze

Modern antifreeze is made up of ethylene glycol or propylene glycol mixed with deionized water. These glycol bases lowered the freezing point and raised the boiling point of water. Water and antifreeze are mixed in a 50/50 ratio to make it ready to add to the coolant system.

Appearance of Antifreeze

Antifreeze has a sweet smell and comes in various pre-diluted colors like green, orange, and red for easy identification in the cooling system. The dye makes leak detection simpler.

Concentration of Antifreeze 

The proper concentration of antifreeze and water is recommended by manufacturers for maximum protection. A 50/50 mix of antifreeze and water is commonly used.

Additives used in antifreeze

Corrosion inhibitors and other additives protect engines. Silicates improve lubricity. Some types extend service life up to 5 years.

Standards of antifreeze formulation

Automotive antifreeze formulations meet ASTM D3306 and other standards for performance, protection, and safety. Propylene glycol is less toxic.

You can also read our full guide on Antifreeze and Coolant here.

What does Antifreeze do?

Antifreeze lowers the freezing point of the engine coolant to prevent it from freezing. This protects the cooling system in very cold temperatures. Here is what antifreeze does:

Lowers the Freezing Point

One of the main functions of antifreeze is lowering the freezing point of the coolant liquid. Water alone freezes at 0°C/32°F, but antifreeze depressants lower this freezing point considerably.

Propylene glycol-based antifreeze can lower the coolant freezing point down to about -37°C/-34.6°F, preventing frost damage in very cold conditions. This protects the engine from freezing and cracking of parts.

Raises the Boiling Point

Additionally, antifreeze raises the boiling point of the coolant liquid higher than 100°C/212°F. Water by itself boils at this temperature.

Antifreeze allows the coolant and engine to safely operate at higher temperatures up to around 108°C/226°F without boiling over. This facilitates dissipating heat at maximum efficiency while driving or in stop-and-go traffic.

Inhibits Corrosion

Antifreeze contains effective corrosion inhibitors that form a chemical barrier on all internal metal surfaces.

These protect against rust, scale, and electrolysis caused by water and air contact with parts like the cylinder head, block, radiator, and more. Keeping the cooling system free of corrosion is critical for long engine life.

Improves Lubrication

Modern antifreeze formulations improve lubrication within the entire cooling system. It reduces friction for better water pump and thermostat operation.

Silicate additives create a slippery film, preventing damage from localized hot spots where metal rubs metal. Overall engine wear is reduced through antifreeze’s lubricating properties.

Ensures Proper Heat Transfer

As the engine’s lifeblood, circulating antifreeze safely transfers heat between all cooling system components.

Its high transfer rate and broad operating temperature range allow excess heat to be efficiently dumped through the radiator under any conditions. Reliable cooling prevents overheating while maximizing power.

Difference Between Antifreeze and Coolant

Here are the main differences between antifreeze and coolant:

Antifreeze:

• Antifreeze is the base liquid, typically ethylene glycol or propylene glycol, that is mixed with water to create the coolant solution.
  
• Its main purpose is to lower the freezing point of water significantly below 0°C/32°F.
  
• Antifreeze provides freeze protection but does not have other additives.
  

Coolant:

• Coolant refers to the premixed solution of antifreeze (glycol) and water.
  
• It typically contains additional additives besides antifreeze, such as corrosion inhibitors, lubricants, leak tracers, etc.
  
• Coolant not only provides freeze protection but also offers boil protection, anti-corrosion abilities, and improved lubricity.
  

Concentration:

• Antifreeze concentration can be any percentage of the glycol base.
  
• Auto manufacturers specify a coolant mixture concentration, usually around 50% antifreeze to 50% water for passenger vehicles.
  

Usage:

• Antifreeze is sold as a concentrated liquid to be diluted with water on-site.
  
• Coolant is a ready-to-use solution for filling cooling systems.
  

So in summary, antifreeze is the base product while coolant is the final formulated solution used in engines, with additional improvements beyond just antifreeze’s freeze protection.

How Does Antifreeze Prevent Freezing and Overheating?

Antifreeze lowers the freezing point of water, preventing it from turning to ice even in very cold temperatures which could crack the engine.

Its higher boiling point also raises the temperature at which the coolant mixture vaporizes, helping regulate temperatures that could cause overheating. Using the proper mixture of antifreeze and water provides reliable freeze and overheat protection.

Also Read: What is OAT Coolant?

Does Antifreeze Corrode or Leak?

Antifreeze helps prevent internal corrosion through its alkaline nature and inhibiting additives. If left unchecked, rust and scale buildup inside the cooling system can cause leaks in water jackets, hoses, or gaskets over time.

Using antifreeze protects costly metallic components from corrosive effects like rust formation or electrolysis that lead to losses in coolant.

How Often Should You Check Antifreeze and Coolant Levels?

Most experts recommend checking fluid levels at least twice per year or before major temperature changes to ensure protection remains.

Low levels can cause overheating from insufficient coolant flow.

Maintain reservoirs halfway between minimum/maximum reference marks for best heat transfer ability.

Catching drops early prevents expensive repairs down the line.

How to Check Antifreeze and Coolant Levels?

Here are the steps to check the antifreeze and coolant levels in your vehicle:

1. Locate the coolant reservoir tank. This is typically a plastic jug located on the driver’s side of the engine compartment.
   
2. Check when the engine is cold for an accurate reading. Hot engine heat can cause coolant to expand.
   
3. The coolant level should be between the “MIN” and “MAX” marks on the side of the reservoir tank.
   
4. If low, unscrew the reservoir tank cap and add premixed coolant slowly until the level reaches the “MAX” mark.
   
5. For some vehicles, you may need to remove a radiator cap to check the coolant level if the reservoir is empty.
   
6. Only remove the radiator cap once the engine has fully cooled down. Rapid cooling can cause a vacuum that may pull the cap off with force.
   
7. The coolant inside the radiator should also be between the “MIN” and “MAX” marks on its overflow/fill tank.
   
8. Add premixed coolant slowly until the level is correct. Replace the radiator cap securely once full.
   
9. Regularly checking the reservoir tank every few months lets you catch small drops in coolant level before damage occurs.
   

Proper antifreeze/coolant level is important for adequate heat transfer and corrosion protection throughout the cooling system.

How Long Does Antifreeze Typically Last?

Under normal driving and with proper coolant changes, most antifreeze formulations last at least 36 months or 36,000 miles before breaking down. Harsh conditions or neglect can cut this lifespan significantly.

As antifreeze degrades, its protection abilities decline and it may need to be replaced more frequently to guard against issues like boiling, freezing, or corrosion risks.

How Can You Tell if Your Vehicle Needs Coolant Service?

Some warning signs include overheating issues, coolant leaks, dirty sludge coolant in the radiator or low fluid levels, sludge buildup inside hoses or reservoirs, and dirty or contaminated-looking antifreeze itself. 

Catching needs early prevents more costly repairs or component failures down the line. Sticking to manufacturer maintenance schedules helps preserve your cooling system.

How to Add Antifreeze and Coolant to Your Vehicle?

Here are the basic steps to add antifreeze and coolant to your vehicle:

1. Check the owner’s manual for the specific coolant recommendation for your vehicle. Make sure to use the correct type of antifreeze or premixed coolant.
   
2. Locate the coolant reservoir, which is usually the plastic tank with a blue or green cap. Remove the cap and check the fluid level.
   
3. If low, you can top it off by slowly pouring in antifreeze or coolant. Replace the cap when full.
   
4. For a full coolant change or flush, locate the drain plug or petcock at the lowest point of the cooling system. Place a drain pan underneath and open it to drain the old coolant.
   
5. Once drained, close the drain plug securely.
   
6. Remove the radiator or expansion tank cap to allow air to escape as you fill.
   
7. Fill the system slowly with premixed coolant and distilled water in the reservoir.
   
8. Replace both caps, start the engine, and let it run to operating temperature.
   
9. Monitor fluid levels and top off as needed. Check for leaks.
   
10. Dispose of old coolant properly at an automotive recycling center.
    

What Happens if Your Vehicle Doesn’t Have Enough Antifreeze?

Here are some of the things that can happen if your vehicle doesn’t have enough antifreeze in the cooling system:

• The engine can overheat, which causes severe damage over time like a warped or cracked head or block. Lack of coolant reduces the system’s ability to transfer heat away from the engine.
  
• The cooling system is more vulnerable to freezing, which can cause cracks or bursts in the radiator, engine block, or clog the heater core if water expands into ice. Frozen coolant could also prevent the thermostat from regulating temperature.
  
• Without proper antifreeze protection, corrosion builds up faster inside the system from the use of plain water. This damages seals, gaskets, water pumps, and other components.

At what temperature does a car need antifreeze?

Antifreeze is necessary when temperatures drop below the freezing point of water, which is 32°F (0°C). The specific temperature range at which antifreeze becomes crucial depends on factors such as the coolant mixture and the climate.

Conclusion

Antifreeze, or coolant, serves as a crucial component in the cooling system, preventing the engine from freezing in cold temperatures and overheating in hot conditions.

Its role in heat transfer, corrosion prevention, and lubrication contributes to the overall longevity of the engine.

Regularly checking and maintaining the proper antifreeze levels, along with adhering to recommended replacement intervals, will safeguard your engine and keep your vehicle running smoothly in various climates.