Low volatility under operating conditions. Volatility characteristics are essentially inherent in the choice of base oil for a particular type of service and cannot be improved by the use of additive materials. Satisfactory flow characteristics in the temperature range of use. Superior stability or ability to maintain desirable characteristics for a reasonable period of use. While these characteristics depend to some extent on the base oil, they are primarily associated with additive materials, which enhance base fluid properties in this area.
Lubricant stability is affected by the environment in which it operates.
Such factors as temperature, oxidation potential and contamination with water, unburned fuel fragments, and corrosive acids limit the useful life of a lubricant. This is the area where additives have made a major contribution in improving the performance characteristics and extending the useful life of lubricants. Compatibility with other materials in the system. Compatibility of lubricants with seals, bearings, clutch plates, etc., may also be partially associated with the base oil. However, additive chemistry can have a major influence on such characteristics.