Your car's engine is complex and contains numerous moving parts. Oil lubricates these moving parts and keeps everything running smoothly. Over time some of the motor oil burns off — leaving a thick sludge behind. This sludge reduces the oil's ability to lubricate the parts properly, which can lead to engine wear. Checking your oil can help determine if the oil needs to be changed and if there is enough in the car.

According to Cars.com, here are some of the reasons why you should change your car's oil:

Oil cools, lubricates and cleans moving parts. Without oil, your engine would stop working.
Oil can become dirty and break down, likely reducing engine efficiency and longevity.
Regular oil changes can help prevent long-term engine damage, which may help you avoid costly repair bills.