What You Should Know About Conventional Oil - Synthetic Oil - Synthetic Blend
There seems to be much confusion these days about the differences between conventional petroleum oil, synthetic blend, and full synthetic oil. Which oil is better? What is fact, and what is fiction? Etc, etc, etc. This article seeks to get you on solid ground with regard to this somewhat "slippery" subject.
Conventional motor oil is refined from crude petroleum oil. Crude oil is a naturally occurring substance that contains millions of different types of molecules, many of these are similar in weight but differ in structure. Because refining separates products by weight, it groups molecules of similar weight including those of dissimilar structure. Refined oils contain a wide variety of molecules, many of which are not necessary or even compatible in the oil. Some of the molecules found in refined oils are detrimental to the lubricated system or even to the oil itself. For example, paraffin, a common refined oil component, causes refined oils to thicken and flow poorly in cold temperatures. Some refined oil molecules may also contain sulfur, nitrogen and oxygen, which can act as contaminants and incite the formation of sludge and other by-products of oil breakdown. Synthetic lubricants, on the other hand, are not refined; they are pure and uniform.
Because they are engineered from pure chemicals, synthetic lubricants contain no contaminants or molecules that don't serve a specific purpose. Synthetic Oils only contain the molecular agents necessary to lubricate and protect components effectively and efficiently. Because synthetic oils contain only smooth lubricating molecules, they slip easily across one another. The ease with which lubricant molecules slip over one another affects the lubricant's ability to reduce friction, which in turn, affects wear control, heat control and fuel efficiency. Uniformity also helps synthetic oils to resist thinning in heat and thickening in cold, which helps them protect better over a system's operating temperature range and helps synthetic oils provide better sealing than conventional oils.
There are five basic types of base oils, and really three different classifications of "synthetic" oils recognized in the United States. This has resulted in some confusion.
Group I Base Oils
Group I base oils are the least refined of all the groups and are usually a mixture of jagged molecular hydrocarbon chains with little or no uniformity. While some automotive oils on the market today still use Group I base stocks, they are more commonly used in less demanding applications.
Group II
Group II base oils are common in most conventional (petroleum based) motor oils. They have good performance in lubricating properties such as volatility, oxidative stability etc, while having only fair performance in areas such as pour point, cold crank viscosity and extreme pressure wear.
Group III Base Oils
Most of the Major Brands of "Synthetic Oil" are really "Synthetic Blends". These are known as Hydrocracked or 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. The best of these base stocks perform much like polyalphaolefin (PAO) based oils. Group III base stocks are considered synthetic motor oil ONLY in the United States. Europe does not recognize Group III based oils as synthetic oil.
In a 1999 law suit brought by Mobil filed against Castrol essentially for false marketing practices, the US Supreme Court ruled in favor Castrol paving the way for them (and any other oil manufacturer) to market this group as "Synthetic Oil". Castrol successfully argued that since group III base stocks were refined further than "conventional" or Group II oils, and the best of them performed somewhat similar to group IV base stocks, that they were essentially synthetic. Group III base oils are rapidly gaining in popularity in the USA.
Group IV Base Oils
Full Synthetics are just that 100% Synthetically Engineered PAO (Polyalphaolefins) oils. Synthetic base stocks are man-made and tailored to have a controlled molecular structure with predictable properties, unlike mineral base oils which are complex mixtures of naturally occurring hydrocarbons. Polyalphaolefins (PAO's) synthetics, when combined with additives (mostly from the group V base oils below), offer excellent performance over the widest range of lubricating properties. In addition to very stable chemical compositions PAO oils offer highly uniform molecular chains. Group IV base oils are becoming more common in the manufacture of synthetic and even synthetic-blend products.
Group V base oils are non-PAO synthetics including diesters, polyolesters, alklylated napthlenes, and alkyklated benzenes among many others. These are primarily used in the formulation of oil additives. Because high concentrations of these chemicals can cause damage to components such as seals, Group V synthetics are generally not used as base oils themselves, rather they serve to add beneficial properties to the other groups of base oils. It is important to note that these additives are NOT among the variety of aftermarket oil additives commonly available; do not add them to your engine oil.
Among the Benefits of PAO Group IV synthetic oils you will find: Temperature (Heat) Control, High Viscosity Index, Thermal and Oxidative Stability, Cold Temperature Fluidity, Friction Control, and Low Volatility which translate in common English to:
- Increased performance
- More power
- Reduced emissions
- Better fuel mileage
- Increased engine life
- Fewer breakdowns
- Extended drain intervals (fewer oil changes)
- Less oil waste (unbelievable Environmental Benefits )
- Decreased dependence on foreign oil
Fully Synthetic oils are the future of lubrication; PAO Synthetic oils are highly synthesized, fully engineered, state of the art lubricants that are used in every type of jet engine in the world, in every form of motorsports racing, every type of industrial machinery, and just about every mechanical application imaginable.
Amsoil was the first API (American Petroleum Institute) recognized Synthetic Lubricant approved for use in automobiles. In 1972 Amzoil (original spelling) introduced the first can of 10W-40 onto the market. Two years later Mobil1 would be introduced in 1974. Others followed slowly but surely realizing the benefits. Now many of the automobiles sold in the world come pre-filled with synthetic oil of various brands. Regardles of the brand of oil, you are far better off to choose either a high quality synthetic blend, or a full synthetic PAO oil. Conventional petroleum oil is slowly going the way of the dinosaur (sorry I couldn't resist).
I strongly support buying American Products from American Manufacturers made by Americans and I am unabashedly unapologetic about it. I do not subscribe to the notion that "the sky is falling" from global warming, but do believe that we should make every reasonable effort to be good stewards of the environmental factors that we can influence, and each American should do as much as possible to end our dependence on foreign oil. I have been involved in Industrial Maintenance and Lubrication in the Paper, Logging, Lumber Mill, and Pharmaceutical industries for over 20 years. I am currently working as an Equipment Reliability Engineer at a major Midwest pharmaceutical manufacturer. I manage a reliability program for the special glass-lined chemical reactors that many of the medications you may get from your physician are made in. My job is to increase production by analyzing the mean time between failures and make recommendations to improve the "up" time of the equipment. In the Pharmaceutical Industry "down time" can cost millions of dollars every day so it is absolutely critical that the equipment be maintained and operated in the best possible manner. Most large industrial manufactures have been using synthetic lubricants for years. There is nothing more important than getting more life out of the equipment, with less down time for maintenance. That is exactly what synthetic lubricants do best; longer service life with less maintenance. This is true in all equipment, not just industrial. I have personally used synthetic lubricants for many years both on the job, and at home.