Originally Posted by
lsvboombox
Here is the reasoning i use for running the motor
"Before you begin an oil change, the engine should be hot. Warm oil is easier to suck through a rubber hose or brass straw, but the reason for running the engine is more essential than that. You are changing the oil because it is contaminated with abrasive and chemical impurities. But the dirt in oil is just like dirt in water; leave it undisturbed and it settles to the bottom. Suck out the cold oil and much of the dirt stays behind, immediately contaminating the fresh oil and defeating the whole purpose of the oil change. Run the engine to get all of the contaminants in suspension so they come out with the oil."