A Case for Synthetic Lubricants
Kinematic viscosity is a measure of a lubricant’s internal friction, or resistance to flow. This is essentially its ability to maintain a lubricating film between moving surfaces and is likely the most important parameter to maintain. Many PAO-based synthetic lubricants provide a higher viscosity reading across their range of temperatures compared to mineral-based oils.
Viscosity Index (VI) describes a lubricant’s viscosity stability as a function of temperature. The higher the VI, the better the lubricant will resist high temperature viscosity changes. VI can also be roughly looked at as a lubricant’s ability to resist oxidation. Synthetic lubricants generally offer significantly higher VI values than mineral oils.
Pour point measures the lowest temperature at which a lubricant will freely pour, and is important for machinery located outdoors. Even though this machine was equipped with a lube oil warming mechanism, the synthetic oil’s much lower pour point will ensure adequate lubrication during cold starts. Synthetic oils do not possess the waxy crystalline structures found in paraffinic mineral oils, and thus have significantly lower pour points.
Flash point determines at what point the lubricant vapor will flash in the presence of an open flame. The synthetic lubricant’s higher flash point provides an increased safety margin in the event of any oil leaks that would result in lubricant vapors that could be ignited.