How to tell if the dealership change your oil

Every car has an oil filter, which is made up of a series of tiny oil-moving parts. The job of an oil filter is to catch falling oil and carry it away, as well as to deliver oil to the car’s various internal parts. If your oil filter doesn’t do its job well, you may end up getting bad oil pressure, which can cause your car to run poorly and overheat. Or in case your car’s previous oil filter was visibly contaminated, the dealer likely changed your oil.