Mineral Base Oils

The first and oldest is mineral oils with no additives. These oils are typically seen in the limited applications where no enhancement to the base oil is needed. Applications of this type are API SA engine oil, barrier oils, seal oils, technical oils, etc.

Due to the strategic advertising directed at the general public for passenger car motor oil, most lubricant end users believe that synthetic equals superior performance over any other type of lubricant regardless of the application.

Synthetic base oils can be many different types of compounds with many being limited to one specific application.     The majors push synthetic base oil lubricants because the primary synthetic is PAO (poly-alpha-olefin).    PAO is a primary product produced by two of the major oil companies in the United States. They heavily market these synthetic lubricants because the PAO base oil provides them with improved profitability over mineral base oil lubricants. One only needs to compare pricing of a mineral oil based passenger car motor oil to     that of a synthetic base to see that the pricing would improve the marketer’s profitability. Independent commodity oil blenders have also jumped on the synthetic bandwagon because it helps them improve profitability.

A limited number of high performance lubricant manufacturers go beyond the synthetic vs. mineral oil argument to truly formulating a superior enhanced lubricant. These lubricants are formulated for superior performance in a specific     range of applications without limitations to the base oil type or performance additives used. If the high performance lubricant manufacturer believes that synthetic base oil with additives is needed for the application then this is how the lubricant is formulated.

In most cases however, these manufactures know that mineral base oil with properly selected and balanced conventional and proprietary additives can be formulated with a robust treat level to provide superior application performance.

Thus, the lubricant end user is given a lubricant that provides superior performance at the most  economical cost for     the application. This is why the lubricant end-users are looking at a synthetic in the first place, because of their desire   for a superior performance lubricant.

Weaknesses of the synthetic based lubricants are: limited additive solubility, reversal of ester based synthetic     base oil  to an acid, seal incompatibility with some seal materials, and a significantly higher per gallon cost     compared to most mineral based oil.

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). Potential on some older pushrod race engines with roller lifters for the roller itself not to spin with camshaft movement, but rather slide while the roller itself remains either stationary or at a lower circumferential speed than that of the camshaft lobe.

Synthetics do not hold lead in suspension as well as mineral oil, thus caution is advised when the engine is run on  leaded fuel. 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 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 & 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." This research was criticized by some because most engine damage appears to be caused by cold starts, and their research method may not have included enough cold starts to be representative of personal vehicle   use.

Enhanced lubricants are designed significantly beyond the minimal formulating done for commercial grade mineral or synthetic base oil lubricants. When formulating these enhanced lubricants, research staff looks for synergistic combinations between the base oil (synthetic or mineral), conventional additives and proprietary additives. This    synergy is what allows the product to provide the maximum performance for the application.

The second step is to determine what conventional additives and what quality levels are available to build the core of   the lubricant around. While commercial grade lubricants are formulated only to a minimal performance level, an enhanced lubricant is formulated well beyond this point. This is accomplished by looking for synergy with high quality component additives, which “enhance” the performance of the lubricant. Additional additive components are then   added at optimum treat levels to assure the enhanced lubricant will deliver maximum performance for the specific application. If the formulation requires synthetic base oil, the main issue is still the additive concentration needed for superior performance. Many times synthetic base oil will not hold enough additive in solution to deliver the needed performance for the application.

The third and final step of formulating an enhanced lubricant is choosing which proprietary additives should be used? Through basic research and proven field performance, high performance lubricant manufacturers will have a number      of proprietary additives that work in specific applications and have proven will enhance the performance of the lubricant. One or more of these additives will be used to fine-tune the enhanced lubricant.

Sure, the synthetic lubricant manufacturer recommends a synthetic. He recommends a synthetic because it brings him better profitability than the commodity mineral base oil lubricant that he is also selling. An article discussing synthetics    in the June 2003 edition of Lubricants World covers how the public has embraced the synthetic concept and how they   do not understand what they are really receiving for the extra money they spend. The article indicates that consumers were “becoming more acquainted with the word “synthetic” and the impression was favorable in terms of better performance than was perceived as available from conventional motor oil.” The article goes on to state that “the public is enraptured by the concept and so the market is growing, despite a higher price.”

In the   continuing debate about synthetic versus mineral oils, the end user is really only interested in protecting the investment they have in their equipment. High performance lubricant manufacturers have lubricants to provide this protection  beyond that offered by major oil lubricant manufacturers and commodity oil blenders.