Lubrication glossary

API is the American Petroleum Institute. It sets quality standards for automotive lubricants, mainly aimed at American manufacturers. Quality levels are identified with two letters. Those starting with S refer to gasoline vehicles, and those starting with C they relate to diesel vehicles. The second letter after the S or C indicates the quality level, in increasing order, API SM being, for example, the highest quality standard for gasoline vehicles and the CI-4 and CJ-4 the highest for diesel.

Compounds incorporated in small quantities into base oils to obtain a finished lubricant with the desired characteristics and performance.

Quality that an oil has to remove air trapped in it. Aeroemulsion is very important in turbine oils and, increasingly, in high severity hydraulic oils. It is an intrinsic property of the base oil and cannot be corrected with additives.

Additive preventing water vapor from combustion or atmospheric condensation from forming rust on parts of the engine.

Additive that causes the oil to degrade slower, as it reduces its oxidation.

Additive that attempts to reduce the friction between moving parts.

1.9 to 1.4 liter displacement vehicles and power between 75-110 HP. Examples: Citroen ZX, Fiat Tempra, Nissan Sunny, Peugeot 306, Renault Megane, Ford Escort, Opel Astra, Volkswagen Golf, Seat Córdoba, etc.

It measures the capacity of an oil to separate from an equal volume of water, after being mixed.

It is the weight of a substance per volume unit. It should not be confused with viscosity. For example, water is denser than oil, (weighs more) but it is more fluid (less viscous). Measured according to ASTM-D-4052.

It is the characteristic/quality of the oil that prevents the engine from getting dirty and forming acid products that wear down parts of it. We could define it in an engine as the ability of the lubricant to remove impurities and waste from metal surfaces produced in combustion.

Additive preventing the solidification or lack of flow of the lubricant at extremely low temperatures.

Liquid lubricant obtained from oil distillation or complex transformations. It is the raw material from which lubricants are manufactured.

Vehicles that are frequently built with multi-valve and turbo systems with a displacement ranging between 1.8-2.2 liters and power between 90-150 HP. Examples: Audi 80, BMW Series 3, Citroen Xantia, Ford Mondeo, Nissan Primera, Opel Calibra, Peugeot 406, Renault Laguna, Seat Toledo, Volkswagen Passat, etc.

Manufactured with lubricant bases obtained directly from oil distillation.

This applies to the wide range of motor lubricants that ensure suitable lubrication both in gasoline passenger cars and in diesel passenger cars.

This is not a fundamental property, nor does it indicate the quality of a lubricant. It is measured according to a scale described in the ASTM-D-1500 standard, and assigns low numbers to clear oils and high numbers to dark oils. The scale ranges from: less than 0.5 to 8 (clearer to darker). The colors of basic oils can be altered by the incorporation of additives, so the color of a finished oil will be determined by these two variables.

Manufactured with mixtures of mineral and synthetic bases.

Since 1995, all the scooters, mopeds and motorcycles have incorporated in almost all their designs an independent system for the oil, with its own tank and pump. The capacity of the tank varies, depending on the manufacturer between 1 and 1.3 liters. The oil is released from a tank by means of a pump that sends it directly to the air/gasoline after the carburetor.

Manufactured with bases that come from complex transformations or synthesis.