Which property of oil is important for resisting extreme pressures?

Viscosity is a critical property of oil that determines its ability to resist flow under pressure. In situations where extreme pressures are encountered, such as in hydraulic systems or in applications involving heavy machinery, the viscosity of the oil is paramount. A higher viscosity indicates that the oil is thicker and more resistant to flow, which is essential to maintain a lubricating film between moving parts. This protective film minimizes wear and prevents metal-to-metal contact, thereby allowing components to function effectively under high-pressure conditions.

Additionally, the viscosity of an oil can change with temperature and pressure, so it is important that the oil maintains suitable viscosity characteristics even when subjected to extreme operational environments. This helps in ensuring that the oil effectively lubricates, reduces friction, and extends equipment life by providing adequate protection against the stresses associated with high pressures.