Like us, your car needs water. In fact, your car needs water just as much as it needs oil.
This "water" in car terminology is known as the coolant. The radiator in your vehicle circulates the coolant around your engine to keep it from overheating.
If your vehicle is low on coolant, it can cause your engine to overheat and even possible engine damage. Therefore, you must check your coolant levels just as you would oil, as it is equally important.
The right time to check your coolant is only when your engine has cooled down, then you can pop the hood. You will see markings that display minimum and maximum levels for your coolant aka water. You want to ensure the levels are between the two. If you are seeing that the levels have fallen below the minimum, it is time to top it off. You can use tap water to bring the levels up, but be sure to have your coolant checked at your next service appointment to keep your engine healthy.
So, the next time you check your engines oils, be sure to check the coolant as well!