Oilers/Plant Tenders (HHC) Civil Service Practice Exam 2025 - Free Oilers & Plant Tenders Practice Questions and Study Guide

Adding additives to lubricating oil serves several critical purposes, one of which is to minimize the oxidation of the oil. Oxidation can lead to the breakdown of the oil, resulting in the formation of acidic compounds and sludge, which can negatively affect engine performance and longevity. The introduction of oxidative inhibitors, a category of additives, helps to slow down this process, ensuring the oil remains effective over its intended service life. By preventing oxidation, these additives maintain the oil's protective qualities, helping to lubricate and protect engine components from wear and corrosion.

The other options do not capture the primary function of additives in lubricating oil. While enhancing color, increasing viscosity, and reducing costs can be relevant in specific contexts, they are not the main objectives associated with oil additives. The focus of additive use is primarily on enhancing oil stability and performance, particularly against oxidation.