How Long Does Coolant Last in a Car? [Detailed]

The coolant is a very important part of the car cooling system. But it cannot last forever. It is important to know how long your coolant lasts so you can make the necessary replacement at the right time. 

The coolant can last you approximately 40,000 to 50,000km or 2 to 5 years. For some vehicles, it is advisable to change it every 30,000km. The lifespan of the coolant will vary with the car you own based on some factors such as the mileage. Therefore, it is advisable to refer to the owner’s manual as well as keep checking the coolant level. 

This article sheds some light on the coolant and how long it is designed to last based on different factors. 

How Long Does Coolant Last in a Car?

how long does coolant last in a car

Coolant consists of both water and antifreeze agents. This combination, together with some additives, comes with several properties that have the ability to improve the performance of any engine.

An example of an additive is a corrosion inhibitor that can be added to the coolant to protect the metallic surfaces of the engine against corrosion. However, the fluid gets more acidic and deteriorates with time. 

This deteriorated liquid is not good for your engine as it can potentially cause severe damage. One of the adverse effects is overheating since the coolant can no longer cool the engine sufficiently. For this reason, car owners are advised to replace the coolant periodically. The levels may also drop for many other reasons such as leakage. 

With that in mind, many drivers would like to know how long a coolant lasts. A new coolant can last you 40,000 to 50,000km or between 2 to 5 years. The variation depends on the type and color of the coolant.

Alternatively, you should keep checking the coolant level in the tank as well as perform a visual check for any impurities. Foreign inclusions tend to change the properties of the composition causing deterioration and may force you to replace the liquid. 

What Are the Factors That Contribute to the Lifespan of the Coolant?

Sometimes, the owner’s manual can guide you on when and how to change your car coolant. However, you must assess this frequency and make the necessary amendments based on the individual characteristics of your car.

Hence, other factors that determine how long a coolant can last include the type of fuel, the operating conditions of the vehicle, the technical condition of the car, engine capacity, and how the car is used.

What Are the Signs That Indicate That the Cooling System Needs Cleaning?

After some time, the cooling system may contain some impurities and other foreign inclusions. This usually warrants cleaning the cooling system and replacing the coolant. Besides a visual check, you can tell this if you notice frequent overheating of the coolant, interruptions when starting a hot engine, and changes in the response of the rheostat. 

What Happens if You Drive a Car With Low Coolant?

The coolant works to ensure that the engine maintains an optimal operating temperature. Hence, it is not advisable to drive with low coolant levels. For one, doing so will cause your engine to overheat and ultimately cause permanent damage.

Moreover, low coolant levels could cause a head gasket to blow causing smoke to emit from the hood. Also, your car is likely to shut off and this can be very dangerous. 

Can You Run My Car With Water Instead of Coolant?

While it is possible to use plain water as an alternative to a coolant, it is not recommended for the long term. It should also not be used in extreme weather conditions. However, using water also comes with several other disadvantages. 

For one, it freezes at 0 degrees Celsius. If you use water for your car’s cooling system during the winter, it will start to freeze causing irreparable damage to the engine. Moreover, in the summer, using water in lieu of antifreeze can be detrimental to the overall health of your engine. 

It is better to use antifreeze that is diluted with water in your cooling system. This mixture plays two roles; it raises the boiling point and lowers the freezing point of water in the cooling system. Therefore, the coolant becomes more effective than water alone. 


Driving with low coolant levels is dangerous, more so for your engine. It may cause serious and often irreparable damage to the engine. When the coolant is not sufficient, the cooling system cannot work effectively, and hence the engine is likely to overheat.

For pure antifreeze, it freezes at about 0 degrees Fahrenheit. However, when you mix the antifreeze with water, in particular in a 50/50 ratio, this freezing point drops to -50 degrees Fahrenheit. Car owners are therefore advised to use the 50/50 antifreeze water mixture. Moreover, the mixture tends to last longer than pure antifreeze. 

Anytime you do a maintenance check, it is important to also check the coolant level. However, you should also note that the coolant can also go bad if it stays too long. The fluid becomes more acidic as it is contaminated by dust and scaling. This condition reduces the coolant’s freezing point as well as its boiling resistance. Therefore, you should regularly replace the coolant even if the car has not been driven for a while. 

Final Words

Coolants are designed to keep the engine at optimum working temperatures. But it is not designed to last forever.

Therefore, it is important to replace the coolant when you notice any impurities or add some more if the levels drop. The sufficient amount of coolant in a car is typically between the min and max marks. 

Related Posts: