MODERN LUBRICANTS PRIMARILY COMPRISE PERFORMANCE ADDITIVES such as dispersants, detergents, oxidation inhibitors, viscosity modifiers, and others, blended in a base fluid (see chapter on Additives and Additive Chemistry). Many properties of the lubricant such as viscosity, viscosity index, slipperiness (reduced friction), film-strength, pour point, oxidation stability, volatility, and flammability, therefore depend on the properties of both the base fluid and the additive package. However, since the base fluid in a lubricant is present in excess of 70%, its contribution towards the listed properties predominates that of the additive package.