Which is typically the cleanest type of oil?

The cleanest type of oil is typically the one that just barely meets established cleanliness targets because it has been subjected to specific testing and standards that ensure a minimum level of cleanliness. This means it has gone through proper filtration and has passed quality control measures designed to eliminate contaminants to acceptable levels.

Using targeted cleanliness standards ensures that any oil meeting such criteria maintains a level of purity that is sufficient for effective lubrication while reducing the risk of wear, contamination, and failure in machinery. While new oil from the drum may initially seem clean, its cleanliness can vary based on storage and handling practices, leaving it more susceptible to contamination before use. Oil filtered using 25-micron filters may not adequately address smaller particles, and waste oil inherently carries contaminants from previous use, making it unsuitable as a clean lubricant option. Therefore, oil meeting established cleanliness targets is well-defined as being cleaner and thus more effective for use in machinery lubrication.