What contributes to a higher Total Acid Number in oil?

The Total Acid Number (TAN) in oil is a measure of the acidity present in the lubricant, which can impact its performance and lifespan. Oxidation of the oil plays a significant role in increasing the TAN. As oil oxidizes, it breaks down chemically, leading to the formation of organic acids. These acids accumulate in the oil and thus raise the TAN value over time.

Oxidation typically occurs when the oil is exposed to heat, air, or contaminants, causing the molecular structure of the oil to change. This process leads to the generation of harmful byproducts that not only contribute to higher acidity but can also lead to other detrimental effects, such as sludge formation and varnish development. Therefore, understanding the relationship between oil oxidation and Total Acid Number is crucial for proper lubrication management and maintenance practices.

Increases in other factors like excessive additives, high moisture content, or low temperatures do not directly correlate with a rise in TAN like oxidation does. While excessive additives can lead to chemical changes, they do not inherently raise the TAN unless they react with the base oil.