What are the symptoms after adding counterfeit engine oil?

[Rich]

After adding inferior engine oil, the lubrication effect becomes difficult to guarantee. Particularly, it exhibits poor wear resistance during cold starts at low temperatures and high-temperature wear due to inferior shear resistance under high temperatures. Heat dissipation also becomes a serious issue, manifesting as unexplained high temperatures in the engine. Carbon buildup caused by high temperatures is inevitable. Due to the poor cleaning capability of inferior engine oil, excessive oil sludge forms, which has poor fluidity and can severely clog piston ring oil injection holes. Definition of counterfeit engine oil: It should not actually be called counterfeit engine oil but rather inferior engine oil, and problems may not become apparent in the short term.