I don't. Motor oil doesn't wash the engine in the usual sense. It is capable of supporting the particulate matter in the suspended state. For this, any motor oil includes "detergent" additives. "Singing" additives do not allow harmful substances to settle on the surface of the metal. Unnecessary particles are removed with oil when the oil is merged. "Singing" additives help to work the dispersion additives that do not allow harmful particles to connect to the combe.
It follows that the stereotype of "dark burnishing-bad oil" is mistaken. The dark color of used oil indicates that the oil effectively links the harmful particles, takes the impurities. Accordingly, if the waste oil is light, it does not perform one of the main tasks-removal of particles and impurities from the engine.
