The Function and formulation of lubricants

The main use of lubricants in motor vehicles (as well as in industrial machinery) is the reduction of friction and wear from mechanical contact and heat.
Friction is the force that opposes movement on two surfaces, while wear is that change that takes place on a surface due to the removal of abrasive debris as a result of mechanical contact, as well as of a chemical-physical nature due to the heat generated by friction.
A lubricant is a balanced mixture of various components. The composition of this mixture, in other words the recipe that a production (blending) plant must follow, is called the "formulation‘.
The formulation of a lubricant is made up of base oils and additives which, when combined, determine the behaviour of the mixture during product use, this both in terms of performance and durability.

The final quality of lubricating oil usually depends on the quality of the base oils used, which are generally classified as follows:

• mineral oils: obtained from the distilling process in the refining of crude oil
• synthetic oils: which are derived from particular physical/chemical laboratory treatments

Compared with mineral base oils, synthetic base oils guarantee:

• a lower level of volatility to a comparable level of viscosity (which leads to lower consumption during use)
• a higher viscosity index (a wider temperature gap)
• greater chemical stability at high temperatures (longer life)

The use of a synthetic base oil in the formulation of a lubricant is generally defined by the performance requirements of manufacturers (regarding volatility, viscosity, longer life), by environmental considerations (non toxicity, biodegradability) or by marketing demands (synthetic oil = high technology oil)