Engine oil is part of the engine of a vehicle. All vehicles that have an internal combustion engine make use of it and no matter how good the oil is, eventually it degrades as the additives get used up. That’s when the vehicles oil should be changed.
The amount of oil a vehicle uses will depend on the type of oil you choose to use, what kind of vehicle it is, and how often its driven. The owners manual can provide more information on these details. However, the old adage suggests every 3 months or 3,000 miles. The amount of mileage driven is more important than the amount of time.
Its important to note that driving in extreme weather or towing a lot of weight behind your car will affect how much oil the vehicle uses.
Not changing the oil after a long period of time can cause the oil to become sludge, eventually clogging the engine.