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The Best

Motor Oil

Valvoline High Mileage with MaxLife Technology SAE 5W-20 Synthetic Blend Motor Oil 5 QT
  • Enhanced anti-wear additives deliver a thick & durable layer of anti-wear film to help...
  • Added detergents help protect against sludge and deposits
  • Premium seal conditioners help treat and prevent leaks
  • Superior antioxidants resist motor oil breakdown in extreme conditions

Read More About Motor Oil

Motor oil, or oil change fluid is any one of the various materials that comprise a motor lubricant, usually enhanced with different additives, most commonly antiwear compounds, lubricants, anti-freeze additives, and, on multi-level oils, viscosity regulators. Motor oil serves as the vehicle's lifeline, delivering sufficient lubrication to make it run smoothly and effectively. Motor oil lubricates internal combustion engines through three mechanisms. First, it improves the fluid's resistance to friction so that the engine runs smoothly; second, it increases the fluid's temperature to make it more viscous so that heat produced by the engine is dissipated rather than adding to cooling; third, it reduces the friction caused by metallic parts so that wear and tear occur at a much more gradual rate.

Motor oils function in at least two of these ways. First, they improve the fluid's friction-resistance properties so that the engine runs smoothly at all speeds. Second, they increase the oils' temperature to facilitate cooling. Both of these are important to a motor oil's ultimate function: to protect the life of the engine. While modern vehicles come with standard oil fluids that are fit for everyday use, specialized oils are available for high-performance vehicles only.

Specialized oils for sports vehicles come in both synthetic and standard varieties. Synthetic oils feature ingredients like Dimethyl Benzine (DBA), or DEB, that work to regulate engine performance at low temperatures by providing lubrication. The synthetic motor oil used in Formula One racing teams delivers more power and less heat in low-temperature conditions. In stock vehicles, synthetic oils are often used to provide additional protection against harmful emissions, especially those emitted by oil refineries.

The purpose of these specialty oils is to keep the engine running smoothly even at extreme temperatures. One of the most common features of these specialized oils is their viscosity index. The viscosity index is a measurement of how much weight a liquid volume can hold before it loses its viscosity and clings to a solid surface. Common motor oils have an index of about zero, meaning they can be thin and nearly water-free. These oils are not the best for a high-performance vehicle. They can soak up engine oils, causing the engine to seize at high revs.

The main ingredient in motor oil with viscosity issues is oil additives. Most common additives have something to do with lubricating the bearings or moving small amounts of gas through the engine. Others act as lubricants for the bearings, increasing their friction-resistance properties. Still, others act as anti-freeze for preventing hydrocarbon bubbles from forming in engine oil.

The majority of performance vehicles do not require high-performance motor oil. What they do require is a good base oil that can prevent erosion and clog. Base oils generally have about ten percent synthetichetics or oil additives. Motor oils that have been specifically developed for high-performance use have even more additives. The majority of these additives are anti-freeze, which prevents hydrocarbon bubbles from forming and extends the shelf life of the lubricant.

Motor oils also contain what is known as a lubricant-type compound, which is designed to work under specific temperatures. To understand why this works, you need to understand how engines work. At higher temperatures, there is a tendency for cooling to stop, which causes the engine to run more slowly. This is because the lubricant compounds tend to be solids and do not dissolve into the fluid.

The solids do not dissolve until the engine is brought to very cold temperatures. At low temperatures, the solids begin to become cohesive and expand into the oil, thus providing lubrication for the engine parts. Motor oils also have a cooling effect on other engine parts, such as radiator cooling fins, carburetor air guides, intake and exhaust pipes, and the likes. When used in conjunction with other lubricants, motor oil effectively performs two functions. It protects your engine parts and extends the life of the parts by preventing hydrocarbon bubbles from forming.