9 Car Fluids You Should Know

Read time: 4.5 minutes

Up to 60% of your car is made up of fluids. Wait, that’s your body. But, your car is powered by fluids too! In fact, just like the human body, cars rely on fluids to keep them running. 

Car fluids, how to check fluids in a car, when to change car fluids, what fluids do I need in my car, When should you change your car fluids

There are nine different fluids coursing through the systems inside your car. Ever wonder what those fluids are? What they do? And, what you should be doing to make them last or work more effectively? At the very least, if you don’t want to fall for the ol’ blinker fluid joke at parties, this article is for you. Onward!

1. gas

We’ll start with the most obvious (and easiest). Unless you’re driving an electric vehicle, you have gas. Fuel is the ultimate fluid to power engines. We won’t spend too much time on this fluid because it’s pretty simple. When you use it up, you fill it up.

2. oil

There are a lot of little moving parts in your engine. And all these little moving parts would grind against one another and generate excessive heat without oil. Oil is what keeps your engine cool and lubricated. If that sounds weird, imagine what an engine would sound like without oil. (Hint: Like the engine equivalent of nails on a chalkboard.)

If there’s one thing most vehicle owners know, it’s the oil change. Engine oil goes to work over the miles between changes and it’s important to exchange the old, worn fluid with new oil. There’s some debate on frequency, so when in doubt, refer to your owner’s manual.

3. coolant/antifreeze

Which is it? Coolant or antifreeze? It’s both actually; it just depends on the season. This fluid is a temperature regulator for your engine. That means it has to keep it cool in the summer and not frozen in the winter. It’s kind of like those fancy moisture-wicking shirts for people who want to stay cool while working up a sweat or warm while hiking in frigid temperatures.

4. transmission fluid

You know how you shift from park to drive and then back to park again because your kid forgot his homework and has to run back inside the house? Transmission fluid is what allows you to shift back and forth to your heart’s desire without damaging the transmission. It keeps those gears lubricated so your kid can forget his homework all he wants and your transmission won’t pay the price for it. 

5. power steering fluid

Ever drive a car without power steering fluid? If so, you know why you need it. If not, imagine using the bulk of your body weight as leverage to turn the steering wheel. In short, it’s not recommended. It’s also not very safe. Power steering fluid is, quite literally, the power behind your steering. 

Fluids. What are they?
6. differential fluid

Differential fluid keeps the gears in the rear or front axle lubricated. It’s more commonly called “gear lube” or “gear oil,” and, without it, there would be a lot of metal on metal contact in the differential. The differential transfers power from the transmission to the wheels. Basically, it’s what lets you turn. Without it, that power steering would be useless and you’d have an impossible time cutting corners. Your days of whipping into a coveted parking space at the grocery store would be done.

7. brake fluid

There’s no question this is a very important fluid. If you want your car to stop, the brake system is going to need brake fluid that’s in good, working condition. How does brake fluid work? Well, you hit the brake pedal and the brake fluid takes that force and allows your brake system to do what it was meant to do. Without it, could you imagine what would happen? Let’s not even go there. Brake fluid is heavily regulated by the Department of Transportation. And for good reason: your family’s safety. Click here to read more about how brake fluid works.

8. air conditioner refrigerant

Air conditioning was quite possibly the most important invention of all time. And, today, it’s the refrigerant that keeps cold air pumping into your car. If you want your car cabin to stay nice and cool in those dog days of summer, make sure you get your climate control system serviced on a regular basis. Ahhhh, that’s nice, isn’t it?

9. Washer fluid

We started with an easy one, and we’ll end with an easy one. How annoying is it when you run out of washer fluid? Isn’t it always when a giant pea-green bug collides with your windshield? Washer fluid isn’t that critical, but it can help keep your line of sight clear. And, well, that’s pretty important when you’re driving.

oil graphic

While your car isn’t made up of mostly fluids, without them your car wouldn’t operate like it’s supposed to (or at all). Fluids are crucial to your vehicle’s operation, your safety and your comfort. (Make note: blinker fluid didn’t make the list… because it’s not a thing.)

Now to answer: Should you be doing anything with these fluids? As you know, nothing lasts forever, including fluids. They lose potency and effectiveness over time, and can even cause major problems if they wear out. It’s best to get your fluids checked on a regular basis. 

Maintenance: it’s all very fluid.

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