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Windshield wiper fluid is one of the easiest car maintenance jobs you can do at home. Due to the chemicals used in most of the washer fluids you can buy commercially, many people opt to make fluid at home. If you’re taking the time to make your own windshield wiper fluid, could you need to take a trip to the liquor store?

A car is covered with snow and ice after a late autumn storm in New Mexico.
A car is covered with snow and ice after a late autumn storm in New Mexico. | Robert Alexander/Getty Images

Can you put alcohol in your wiper fluid?

When making your own wiper fluid, finding a good substitute for methanol is important for cold weather. Alcohol freezes at a much lower temperature than water so it’s optimal for cold weather. 

YourMechanic states that high-proof Vodka can be used but rubbing alcohol is recommended. NewsWheel even recommends it as a homemade de-icer.

Deciding whether to waste your vodka on your windshield is a whole other dilemma though.

What else can you substitute for windshield wiper fluid?

It depends on the conditions where you drive. YourMechanic has two ways to make warm-weather windshield wiper fluid, one for cold weather, and two for all-weather conditions.

For warm weather, YourMechanic recommends filling a gallon jug three-quarters full with distilled water. Fill the rest with white vinegar but keep some space in the container to mix. 

Keep in mind using vinegar may cause an unpleasant odor, though, so another option for warm weather is to mix distilled water and window cleaner instead. Use the same ratios as the first mixture but make sure to use window cleaner that doesn’t streak so your windshield can remain clear.

For cold weather winter driving, it’s important to avoid those first two mixtures. Vinegar and window cleaner freeze in extreme cold and that can cause damage to nozzles and hoses. The best way to ensure it works effectively in cold weather is to add alcohol. 

Take a jug and fill it three-quarters full with distilled water again. Then add enough white vinegar to fill up the rest of the jug with just enough space to mix the two. Add one cup of rubbing alcohol (or vodka) and mix it well. Leave it overnight in freezing conditions to make sure it won’t freeze in lower temperatures. If it does, simply add more alcohol.

For all-weather conditions, the mixture changes slightly. The first method from YourMechanic involves a large jug, distilled water, dish soap, and ammonia. Fill the jug with one gallon of distilled water before adding a tablespoon of dish soap and mixing it well. 

Similar to the case of window cleaner, make sure to use dish soap that doesn’t streak. Add a half cup of ammonia to the water/soap mixture to prevent freezing and clean your windshield. YourMechanic notes that it may not work in extreme cold but should be effective in cool temperatures. 

Another all-weather mixture for windshield wiper fluid uses alcohol. Like in the previous mixture, add one gallon of distilled water to a large jug. Then add eight ounces of rubbing alcohol to the water and mix well. 

Once that’s mixed, add a tablespoon of castile soap. Castile soap may be safer for your car’s paint because it contains more natural ingredients. For cooler temperatures, YourMechanic recommends adding more alcohol to prevent freezing.

Is using homemade windshield wiper fluid a good idea?

Making your own windshield wiper fluid is a great way to save money and use potentially less harmful chemicals than what you find in commercial fluids. Homemade windshield wiper fluid is quick and easy to make for any weather condition as well. 

Once you’ve made homemade windshield wiper fluid, be sure to test it on your windshield. Dab some onto a clean cloth and rub it in to see how effective it is. Locate your car’s washer fluid reservoir and, if it’s effective, add your homemade mixture to the reservoir. 

Make sure to pay attention to how it works after you add the fluid. If it’s causing streaks or not spraying properly, it may not be best for your car. Stop using that immediately and get a mechanic to examine your washer system in case you have clogged washer fluid tubes.
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