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With all of the negative articles about oil additive, which have been written and supported extensively by special interest groups, its time to tell the real truth about oil additive. In most cases they perform a positive function and with regular use can provide a number of benefits to vehicles and equipment.
First, lets get one thing clear, it’s important to distinguish from oil additive developed by companies that have been extensively tested, and others, usually made by individuals, without such testing and documentation. Anyone can put an additive package together and have a label made. There are many on the market, which have no real testing, even though, they claim they do. This is where additives have gotten a bad name. On the other hand there are a number of companies that sell additives that have extensive research and development teams that have tested their additive packages.
In actuality additives are used in most all lubricants, because even the best synthetic base oils cannot protect vital parts alone, as it’s the additives that do all of the work. Let’s concentrate on the internal combustion engine in looking at the need for additives.. Moderate-speed driving on short trips or stop-and-go driving in traffic uses only a fraction of the available engine power. Because the cooling systems must be capable of meeting the cooling requirements of the engine at high speeds, they may overcool the engine in short-trip driving. In such light-duty service engines and motor oils warm up slowly and often do not reach proper operating temperatures.
In contrast legal speed limit driving and long trips allow the engine and oil to warm p properly. The choke is open, and the carburetor is feeding the cylinders with a lean, clean burning air-fuel mixture. As a result there little or no incomplete combustion to produce soot other residue. Under these conditions water compensation is not a problem, nor is dilution of the motor oil by raw fuel.” Additives have been developed to address these problems as most of us qualify much of time for driving in severe service conditions. Furthermore, the API goes on to say “Under some conditions it is impossible to maintain a continuous oil film between moving parts, and there is intermittent metal-to-metal contact between the high spots on sliding surfaces. Lubrication engineers call this boundary lubrication. Under these circumstances the load is only partially supported by the oil film. The oil film is ruptured, resulting in significant metal-to-metal contact. When this occurs, the friction generated between the surfaces can produce enough heat to cause on or both of the metals in contact to melt and weld together. Unless counteracted by proper additive treatment, the result is either immediate seizure or the tearing apart and roughening of surfaces.
Boundary lubrication conditions always exist during engine starting and often during the operation of a new or rebuilt engine. Boundary lubrication is also found around the top piston ring where oil supply is limited, temperatures are high, and a reversal of piston motion occurs.
Extreme pressure conditions can develop between heavily loaded parts from lack of lubrication, inadequate clearance, extreme heat, and sometimes as a result of using the wrong type or grade of lubricant for the operating conditions of the engine. Since motor oils do not contain extreme pressure agents this is an area that aftermarket additive manufacturers focus a lot of attention. In modern engines the valve train with its cams, valve lifters, push rods, valve stem tips, and parts of the rocker arms operate under conditions of extreme pressure because they carry heavy loads on very small contact areas. Unit loading, which may be as high as 200,000 pounds per square inch, is many times greater than the loads on the connecting rod bearings or on the piston pins.” Motor oils rarely contain extreme pressure additives, thus premature wear could take place. The preceding has laid the groundwork for the need for additives. Additives to take care of the deposits and sludge, called detergent/dispersant additives, anti-oxidants to delay the effects of oxidation. Anti-foaming additives are important as if foaming occurs in a motor oil the film strength is reduced allowing wear. And since base oils alone cannot withstand the metal-to-metal contact inside an engine, anti-wear agents are needed. With acids there is also a need for corrosion inhibitors; and in reducing friction in hydrodynamic lubrication such as on the cylinder liners, where metal-to-metal contact does not occur, friction modifiers or lubricity additives are desired to improve engine efficiency and improve mileage.
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