When I was young, no one told me (OK, fine, I ignored the fact) that cars need their oil and other fluids changed. Poor old Volvo ….

Now that I’m a super-mature grown-up (ahem), I know that regular oil changes are a must. But what about all those other mysterious fluids that make our car run? Do they need our attention too?

The answer is yes, they do. So for those of you who relate to young Jessica, here’s a simple breakdown of the types of car fluid that keep your vehicle running smoothly.

Motor oil … what does it actually do?

Changing your car’s oil is one of the most common car maintenance chores. But what has the stuff ever done for us?

Simply put, oil lubricates your engine. Because there are so many moving parts under your hood, oil reduces friction and keeps your engine from overheating. This lubrication also prevents rust by blocking oxygen from getting to the metal. And, as if it isn’t working hard enough already, oil traps dirt and other particles, leaving them behind in the oil filter (which is why it also pays to change your filter periodically).

So next time you’re due for an oil change, think about everything oil’s done for you lately and wipe that grimace off your face.

Transmission fluid: the other dipstick

There are 2 dipsticks under your hood: one to check your motor oil and one to check on that underrated worker bee, the transmission fluid. Transmission fluid performs many of the same functions as motor oil, like lubrication and cooling. As transmission fluid moves through an automatic transmission, it gets pressurized, which provides the hydraulic power needed to perform the transmission’s basic functions, like shifting gears.

For those of you with a stick shift, manual transmissions also require lubricant, but often use a different kind that has to be serviced from underneath the car (which means no dipstick).

Where does antifreeze stand on the whole freeze vs. no freeze debate?

Duh. Antifreeze wants nothing to do with freezing (or boiling for that matter). Adding antifreeze to the water in your radiator (a 50/50 mix is recommended) lowers the freezing temperature of the water, which helps prevent freezing in cold weather. After all, you want to keep your engine cool, not frigid.

Antifreeze can also protect that same water from boiling in the heat (hence its other name, coolant), but the name “antifreezeandboil” was a bit cumbersome.

Think you’ve seen it all? Well hold onto your hats because this overachiever even prevents corrosion and provides lubrication for the water pump.

Washer fluid is just water and colored soap, right?

Nope. Washer fluid combines several chemicals in order to perform services that soap and water alone couldn’t do. Standard washer fluid usually includes methanol, which can break down bug guts (yum!), as well as ethylene glycol, also common in antifreeze, to lower the freezing temperature of the washer fluid (unless you live in a warmer climate where antifreeze is less commonly added).

The good news is that more companies are now creating non-toxic washer fluids that still perform the same tasks as the other stuff. And some people even make their own washer fluid using household items. The Sierra Club recommends combining rubbing alcohol, liquid dish detergent, and water for a greener version.

What?! Even my brakes have fluid?

Hopefully. Because without brake fluid, you’re hosed. Like transmission fluid, brake fluid gets pressurized and provides the force that activates your brakes. When you push on the brake pedal, it engages a plunger in the master brake cylinder, which forces the brake fluid through a series of tubes and hoses and then into the braking unit of each wheel.

It sounds like a slow process, but for anyone who’s had to slam on the brakes to avoid a daredevil squirrel, we know that fluid moves fast!

Does power steering fluid truly give me power?

Similar to many of the other fluids in your car, power steering fluid provides lubrication for the steering gear and makes it easier to steer your car. When you turn the steering wheel, a small opening allows pressurized power steering fluid to move in and help you direct the front wheels. If that’s not power, I don’t know what is.

Now that you know your car fluid types, make sure to ask your mechanic to check all of them for a better picture of your car’s performance.

Class dismissed.

Related posts

Car maintenance by the mile: what your mechanic isn’t telling you
4 reasons not to panic when your check engine light comes on

DIY hacks | For your car | For your finances

about Jessica

During her time as senior copywriter at Esurance, Jessica wrote about everything from automotive trends to insurance tips to driving dogs (it’s a thing!). In her free time, you can find Jessica hiking with her dog (who cannot drive), devouring a good mystery, or very slowly learning Spanish.