Can You Mix Windshield Washer Fluid? Things You Need To Know

We have all done it, your windshield washer fluid has just run out. So, you go to your nearest auto shop only to find that they don’t stock the brand you usually use.

Because you can’t drive without windshield washer fluid, you decide to get another brand. After all, don’t these products do the same job?

You head to your car with your new windshield washer, and because you don’t have time to drain the other liquid, you just pour and mix the two washer fluids. What most of us have never thought about is whether is it okay to mix windshield washer fluids.

Well, two things may happen when you mix windshield washer fluid. If the formulas used to make the two products are the same, then everything is going to be fine. The problem comes in when the formulas are different.

Windshield washer fluids such as Rain-x are often made through unique processes and when mixed with other washers, it may counter the effects of one of the products. And you may not enjoy all the benefits such as thorough glass cleaning.

Mixing windshield washer fluids won’t result in an explosion because there are no chemicals used. However, your glass won’t be cleaned thoroughly and if the ingredients don’t blend well, you may end up with a dirtier windshield instead.

As a car owner, you need to be careful with the products you put in your car.

Most motorists are only careful with what they put in the engine and don’t pay much attention to other car fluids such as windshield washers.

However, windshield washer fluid plays a critical role in the visibility and aesthetics of the car.

If you mix two products that aren’t supposed to, then chances are, you will end up with a dirty windshield which puts you at a higher risk of being involved in an accident.

For safety purposes, I would recommend that you stick to one windshield washer fluid.

Windshield washer fluid

Does Mixing Windshield Washer Fluids Improve or Lower Effectiveness?

If you have been researching the effects of mixing windshield washer fluids then chances are you have come across two different opinions.

Some say that the two products work better and some claim the effects are lowered. You are probably wondering which information is more valid.

Windshield washer fluids are formulated to offer the following services; clean the windshield, ensure water glides off the windscreen faster, melt snow, and many other benefits. Each windshield washer fluid has its perks and that’s why mixing them isn’t the best idea.

Unless the products are similar, the effects of mixing two windshield washer fluids can be disastrous. If it ends up causing beading on your screen then you will have no other option than to empty your washer’s reservoir.

The bottom line is, that mixing windshield washer fluid lowers the effectiveness of both products. In some cases, if the formulas are different, the mixture will cause the beading of water droplets on your windscreen hindering visibility.

What Do Experts Think about Mixing Windshield Washer Fluids?

A while back, I came across a post where a certain driver was complaining about how a clerk at an auto shop convinced him to mix Rain-x with ordinary washer fluids. Only for his car’s wiper fluid dispensers to get clogged after a week.

As a car owner, there is one thing that you need to know. Just because someone is working at an auto store, that doesn’t make him/her an expert.

Most of these guys are just skilled salespeople and don’t know anything about cars. So, if you walk in there clueless hoping to get expert advice, they will tell you anything so that you can make a purchase.

Car manufacturers wouldn’t recommend mixing windshield washer fluids. Heck, they don’t even recommend the use of such products on their cars.

Professional detailers and mechanics might advise you to use windshield washer fluids because of the numerous benefits that they offer.

However, they won’t ask you to mix up anything. Don’t be misled to think that mixing two washer fluids will create a more powerful one.

Listening to the wrong advice might put you in the same situation as the guy I have mentioned above. Always research a product before using it on your car.

And regarding windshield washer fluids, don’t mix products without knowing the effects that might occur.

Why Do People Always Mix Windshield Washer Fluids?

The main reason why most people mix windshield washer fluids is that they don’t get the same brand every time they shop for such a product.

This forces them to go with another brand and mix it with whatever remained last time. Being a common thing, most people rarely notice any issues after mixing windshield washer fluids.

The only problem is that one day, you might mix two different products and end up with unsatisfactory results.

What about Mixing Summer and Winter Windshield Washer Fluids?

These two windshield washer fluids are designed for different environments. Mixing them might not affect your fluids’ cleaning properties but the freezing resistance will be affected.

More so, if you are heading to winter add winter windshield washer fluid to the summer one. That mixture won’t be able to easily melt snow. And that can make driving quite inconvenient.

In such cases, instead of risking mixing these two products. Drain your wiper reservoir and let clean water run through it. Then, pour your winter windshield washer fluid so that you can enjoy its benefits at full strength.

Can I Mix Homemade and Manufactured Windshield Washer Fluid?

Did you know that you can make your windshield washer fluid? A lot of people prefer at-home washer fluids because they are easier to make and are gentler on the car’s wiper tank and system.

The only downside is that they are not as effective as manufactured windshield washers.

Never mix these two types of products at all. You are better off mixing two manufactured windshield washer fluids than mixing one of these with an at-home washer.

Because of the huge difference in ingredients, you may end up corroding your wipers and the windscreen itself. The mixture might also lower the effectiveness of either of the products.

What If I Mix Windshield Washer Fluid with Water?

Anything that is mixed with water becomes diluted. This is exactly what will happen when you mix windshield washer fluid with water.

Some motorists put water in the windshield reservoir. This has its advantages and disadvantages. Water is harmless on both your reservoir and windscreen.

But, it isn’t strong enough to keep your windshield clean or melt ice when driving during the snow. Water also has another disadvantage, it may leave behind calcium deposits that can block the windshield dispensers.

Will Mixing Windshield Washer Fluids Make It Last Longer?

Probably not. The amount of windshield washer fluid that you would have used in a month is the same amount that you are going to use whether you mix it up or not.

The only difference that may arise is when you mix two products, they may not be as effective. Therefore, forcing you to spray more of the mixture in an attempt to clean up your windscreen.

Should I Mix Windshield Washer Fluids If They Have the Same Color?

Just because two fluids have the same color doesn’t mean that they share the same formula. Quite often, car owners make the mistake of mixing two windshield washer fluids just because they have the same color.

Nothing may happen at first. But if these two products don’t mix, you will end up with lots of beads on your windscreen or streaks.

Should I Mix Antifreeze with Windshield Wiper Fluid?

These two perform the same task but on different components of the car. As a result, one may be confused and mix the two. This is very wrong and if either of these products finds themselves in the wrong car system, it may have toxic effects.

Antifreeze, also known as coolant, is supposed to be poured into the engine. It keeps your engine from overheating in summer and freezing in winter. Windshield wiper fluid on the other hand is formulated to melt ice on the windscreen during the snow.

As you can see above, these two products may perform the same job but should be used on the specified car components.

Does Windshield Washer Fluid Go Bad?

Knowing this information is crucial because it will help you determine whether it’s okay to pour new windshield washer fluid on an old one that has been on your car.

Windshield washer fluids often degrade after a couple of years. And for a car that is being used regularly, your washer fluid will run out in at least 6 months.

So, the odds of you pouring washer fluid on another that has gone bad are very low. Not unless your car has been sitting for years.

Is It Bad to Mix Windshield Washer Fluid?

The answer is both yes and no. A lot of people mix windshield washer fluids and nothing happens. Provided the formula in both products is the same, you are likely not going to notice any changes.

However, the level of effectiveness is likely to deteriorate. The mixture won’t be as strong as sticking to one particular brand.

Was this article helpful?

Leave a Comment