Supplemental coolant additives protect metal surfaces of the cooling system against what?

Supplemental coolant additives are specifically designed to enhance the performance of engine coolants, primarily by protecting metal surfaces within the cooling system. These additives serve several important functions, including preventing damage and corrosion caused by the continuous exposure of metals to water and various chemical reactions occurring within the coolant.

Corrosion can be particularly detrimental to the longevity and efficiency of the cooling system, leading to leaks, reduced heat transfer efficiency, and potential failure of components like the radiator, water pump, and engine block. By inhibiting these corrosive processes, supplemental coolant additives help maintain the integrity of these metal surfaces, prolonging the life of the cooling system and ensuring it operates effectively.

While options related to propylene and ethylene depletion touch on different aspects of coolant chemistry and formulation, they do not directly address the primary function of supplemental coolant additives in preventing damage and corrosion. The presence of these additives is integral to maintaining a well-functioning cooling system, thus supporting the choice that identifies their core protective role.