Coolant Vs Windshield Wiper Fluid

The principle of automotive fluid is simple- that is to make the machine do its work properly. Apart from the engine, our vehicle has other important systems such as radiator and windshield wiper. The work of both is poles apart as well as their fluid. So, what are the dissimilarities?

What is the difference between coolant and windshield wiper fluid? Coolant fluid works to keep the temperature stable with glycol compounds while windshield fluid uses different alcohol mixes to keep the windshield clean and visible.

It would be a wise job if you know which one to use among these fluids. So this is just a short version. Let’s explain it a bit more.

What's Inside:

Windshield Wiper Vs. Coolant Fluid

The use and absence of several contents make them different. For instance, WW fluid uses de-icing compounds while the antifreeze fluid doesn’t. Let’s know about them in detail.

Windshield Wiper Fluid

Such fluids mainly work to keep the windshield clean. However, they also lubricate the mechanisms that run the wipers.

Some of the common windshield wiper fluid ingredients include water, methanol (de-icing agent), isopropanol, and other combinations with some detergents. These alcohols ensure the breakdown and removal of grease and debris in the system. Moreover, it may have small amounts of antifreeze agents made of methylated spirits so the liquid doesn’t freeze in cold temps.

It generally comes in light blue so that people don’t confuse it with coolant or other fluids.

Coolant Fluid

Coolant helps make the radiator prevent your vehicle from overheating and freezing by absorbing, transferring, and dissipating heat in the air. It regulates the temperature in the system and defends components against corrosion.

The fluid is a half-and-half mix of water and ethylene or propylene glycol coming in a 50:50 ratio. Here, the glycol ensures that the fluid doesn’t freeze at extremely low temperatures. It also protects the radiator from boiling-level heat. Apart from the major contents, it also has additives like antifreeze and anti-corrosion agents.

Coolant is usually greenish or bright yellow so that it’s easy to detect the fluid among other variants.

Using Windshield Wiper And Coolant Fluid Interchangeably

Having somewhat similar contents, can you use windshield wiper fluid as coolant or vice versa? No, we won’t recommend using coolant and WW fluid interchangeably. This can be harmful to both systems.

So, can coolant be used as windshield wiper fluid? No, adding coolant fluid to the wiper reservoir can damage the paintwork of your vehicle, especially the front part. Why? Because it has paint-stripping properties. Plus, such fluids have little to no cleaning power to ensure visibility.

Now, what if I put windshield wiper fluid in coolant? Using windshield wiper fluid in the cooling system can put it at risk of the radiator freezing at subzero temps. Plus, the de-icing agent in the fluid can become extremely corrosive to the radiator in such a situation.

You’ll even find warnings against swapping in the manuals of your vehicle.

You can also see: What Happen If I Put Wrong Oil In Car?

Comparison Chart Of Coolant And Windshield Wiper Fluid

Factors	Coolant	Windshield Wiper Fluid
Purpose	Keeps radiator from overheating or freezing.	Keeps the windshield clean.
Other Uses	Prevents corrosion.	Lubricate the wipers.
Contents	Water and ethylene or propylene glycol; detergents, antifreeze, and anticorrosion agents	Water, methanol (de-icing agent), ethylene glycol, isopropanol; additives like antifreeze agents.
Color	Greenish or bright yellow	Light blue

Frequently Asked Questions

How To Check Coolant And Windshield Fluid Level?

Checking both coolant and windshield fluid is an easy task.

For the cooling system reservoir, check the markings on the side of it. You don’t need to open the cap. The tank should be labeled coming in translucent plastic that helps you see the fluid level and condition.

As for the wiper system, you just need to open the hood and locate the reservoir near the windshield base or at the back of your engine bay. It should be translucent with markings on the body and have a designated symbol on the cap. With this, you can easily check the level. Another easier method can be to engage engine sprayers and see if fluid comes out.

Whatever you do, just wait for the engine to cool before you go for it.

Can You Mix Coolant And Windshield Wiper Fluid?

No, coolant mixed with windshield wiper fluid is never a good idea since it can become a contaminant and lead to system damage. Doing it will reduce the efficiency of both fluids.

One will cause paint stripping while the other will cause corrosion. In this case, you can neither use the mixture in cooling system nor put it in the wiper.

What Can I Use Instead Of Windshield Wiper Fluid?

You can make DIY windshield wiper fluid with a solution of water and glass cleaner in a 1:3 ratio. Add a few drops of liquid dish soap to get optimal properties of cleaning.

Another efficient recipe would be to mix 8oz. of rubbing alcohol, castile soap, and a gallon of distilled water. You can adjust the alcohol amount depending on the weather conditions (mild to extreme).

Final Words

Because the fluids have some similar properties, this can make you think- Is coolant the same as windshield washer fluid? But, no they aren’t same, the formulations are different from one another and designed for specific systems and purposes. This makes the use of both unsuitable to be used as substitutions.

Hence, we suggest you don’t mix or swap one for other to avoid accidents.