Your vehicle's lubricating oil has two main ingredients: the base oil and then additives. The base oil is what lubricates your vehicle engine's moving parts, and that reduces friction which leads to excessive wear. The additives are there to prevent the heat from the engine's operation from breaking down the oil.

The base oil is refined from crude oil. Crude Oil is "refined" are made more pure, to remove contaminants like wax, nitrogen compounds, and sulfur and to take out the unsaturated hydrocarbons. Refining involves the following processes: Extraction of Solvents, Hydrofinishing, Hydrotreating, and sometimes Hydrocracking and Hydroisomerization. Is it important to know that? Probably not, what all these steps do is make the oil more "pure" for use in your engine.


A more important thing for the vehicle owner to consider is the "Additives" in the engine oil. The Base oil alone isn't strong enough to protect the engine properly. Motor oil needs work for many different functions, and under big difference in operating conditions.

Detergent/dispersant additives, Rust and corrosion inhibitors, Antioxidants, Anti-wear additives are all added to help the oil work better in the engine. Many oils add Viscosity modifiers to make the motor oil pour and better.


Oil gets thinner when it's heated and thicker when it cools. Motor oil, in order to lubricate your engine correctly through the changing seasons, needs to be the proper "viscosity" (Thickness) to match the ambient temperature in your region. This is an important characteristic to motor oil..

A single, or mono, grade oil's viscosity is ideal only one temperature range, normally either cold or hot. A multi grade oil must be able to meet both high and low temperature viscosity requirements at the same time. Multigrade oil is the best year-round choice for many drivers who go through both hot summers and cold, harsh winters. You can tell a multigrade oil by the dual viscosity designation (as an example 10W-40 where the 10W is the low temperature and the 40 is the high temperature rating). The viscosity modifiers we discussed above help to make the oil thicker at high temperatures but don't work at low temperatures.