What is a consequence of oxidation of lube oil due to overheating?

The oxidation of lube oil due to overheating leads to a chemical breakdown of the oil, which causes various detrimental effects. One significant consequence is sludge formation, where the breakdown products can coagulate and create thick deposits that accumulate within the engine or system.

As lube oil oxidizes, it can generate byproducts that are thick and pasty in nature, resulting in sludge. This sludge can obstruct oil passages, hinder proper lubrication, and limit oil flow throughout the system. It can also result in increased wear on components due to insufficient lubrication and can lead to blockages that exacerbate temperature increases and further oxidation.

In the context of the other options, while increased viscosity and reduced efficiency can occur as a result of oxidation, the formation of sludge is a more immediate and recognizable consequence of overheating. Enhanced lubrication should not occur as a result of oxidation—in fact, the opposite is true, as oxidized oil loses its lubricating properties over time. Thus, recognizing sludge formation as a primary consequence of oxidation emphasizes the importance of maintaining lube oil at appropriate temperatures and conditions to prevent degradation and ensure system longevity.