Royal Purple Street Synthetic Motor Oil - SAE 5w20, Quart Bottle, Pack of 12
Thursday, September 16, 2010
Royal Purple Street Synthetic Motor Oil - SAE 5w20, Quart Bottle, Pack of 12 Review
Synthetic oil is a lubricant consisting of chemical compounds which are artificially made (synthesized) using chemically modified petroleum components rather than whole crude oil. Synthetic oil is used as a substitute for lubricant refined from petroleum when operating in extremes of temperature, because it generally provides superior mechanical and chemical properties than those found in traditional mineral oils.
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In the 1970s, typical cars took 10W-40 oil which was used for a duration of 2,000 mi or less[citation needed]. In the 1980s, to improve fuel economy and engine performance 5W-30 oil was introduced which was then used for a duration of 3,000 miles. A modern typical application would use 5W-20 viscosity oil or synthetic oils for durations greater than 7,500 miles.
From the early 1980s most oil change shops have been recommending an oil change every 3,000 miles. During the following decades engine technology and oil technology have advanced requiring less frequent oil changes under normal driving conditions.
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Synthetic motor oils are man made oils from the following classes of lubricants:
*Polyalphaolefin (PAO) = American Petroleum Institute (API) Group IV base oil
*Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, etc.)
*Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005, production of GTL (gas-to-liquid) Group III base stocks began, the best of which perform much like polyalphaolefin. Group III base stocks are considered synthetic motor oil only in the United States;[13] elsewhere they are not allowed to be marketed as "synthetic".
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The technical advantages of synthetic motor oils include:
*Measurably better low and high temperature viscosity performance
*Better chemical & shear stability
*Decreased evaporative loss
*Resistance to oxidation, thermal breakdown and oil sludge problems
*Extended drain intervals with the environmental benefit of less oil waste.
*Improved fuel economy in certain engine configurations.
*Better lubrication on cold starts
*Longer engine life
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The disadvantages of synthetic motor oils include:
*The lower friction may make them unsuitable for break-in (i.e. the initial run-in period of the vehicle) where friction is desirable to cause wear. Improved engine part machining has made break-in less critical than it once was, though. Many modern cars now come with synthetic oil as a factory fill.
*Potential decomposition problems in certain chemical environments (industrial use dominantly)
*Potential stress cracking of plastic components like POM (polyoxymethylene) in the presence of PAOs (polyalphaolefins).
*Synthetics do not hold lead in suspension as well as mineral oil, thus caution is advised when the engine is run on leaded fuel.[citation needed] As an example, leaded fuel is still commonly used in aviation (avgas).
*In July 1996, Consumer Reports published the results of a two year motor oil test involving a fleet of 75 New York taxi cabs and found no noticeable advantage of synthetic oil over regular mineral oil. In their article, they noted that "Big-city cabs don't see many cold start-ups or long periods of high speed driving in extreme heat. But our test results relate to the most common type of severe service -- stop-and-go city driving." According to their study, synthetic oil is "worth considering for extreme driving conditions: high ambient temperatures and high engine load, or very cold temperatures."
*Synthetic oils are not recommended in automotive rotary engines
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Posted byJess at 7:00 PM
Labels: Bottle, Purple, Street, Synthetic