Which of the following actions is best for a clean oil filter?

Replacing the oil filter frequently is essential for maintaining the overall health and efficiency of an engine or system. Over time, oil filters accumulate contaminants and particles from the engine oil, which can lead to blockage and reduced filtering capability. A clean oil filter ensures that the oil circulating through the engine remains free from contaminants, thus protecting critical components and enhancing performance.

Regular replacement of the oil filter prevents issues such as reduced oil flow, increased wear on engine parts, and potential engine damage due to debris. It is a proactive maintenance strategy that contributes to the longevity and reliability of the entire lubrication system.

The other options do not directly contribute to maintaining a clean oil filter. Repainting the filter does not affect its performance and might even hinder proper functioning. Altering oil viscosity or temperature may have effects on oil circulation and engine operation, but they do not inherently keep the oil filter clean.