Which brand of engine oil has the best cleaning effect?

Among several major brands, the engine oil dedicated to cleaning dispersion is Shell Lubricating Oil.

In addition to lubrication, oil also needs to dissipate heat and clean the engine. Each brand of engine oil has its own emphasis. For example, the low-temperature liquidity pursued by Castrol. Its slogan is "Before it is started, protect it first".

Mobil pursues the ability to resist oxidation and decay at high temperature. Therefore, under the same circumstances, the oil change cycle of Mobil oil is relatively longer.

Shell's main pursuit is clean dispersion. Therefore, every time the oil is maintained, Shell is blacker than other brands. This is not because the degree of oxidation is higher. It's just the result of cleaning up all the worn impurities inside the engine.