Oil - All You Ever Wanted To Know

Oil - All You Ever Wanted to Know

Lubricant Basestocks

Top Quality Basestocks are the Key

Someday soon, we won't have conventional basestocks to kick around anymore. Superior basestocks and stricter motor oil specifications are squeezing conventional basestocks out of the market. The next passenger car oil performance specification, International Lubricants Specification and Approval Committee (ILSAC) GF-3, looks as though it will have significantly tighter volatility limits than the current ILSAC GF-2 spec has, tighter limits than conventional basestocks can meet on their own.

In fact, Harts Lubricants World (Nov. 1997) writes that demands for greater thermal stability, oxidative stability and lower volatility coupled with higher standards for automatic transmission fluids, "will soon make Group I solvent-refined oils obsolete, unless they are blended with higher quality products or synthetics to correct their limitations."

While synthetic basestocks have been available for decades, and define the quality standard for basestock performance, hydroprocessed oils and their allies are relatively new. It is the appearance of these new, highly processed mineral oils that spells the end of conventional oil, or at least its dominance of the basestock market. What Is a Conventional Basestock? Is Unconventional Basestock = Synthetic?

The American Petroleum Institute defines five groups of basestocks. Groups I, II and III are mineral oils classified by the amount of saturates and sulfur they contain and by their viscosity indices. Group I basestocks are solvent refined mineral oils. They contain the most saturates and sulfur and have the lowest viscosity indices. They define the bottom tier of lubricant performance. Group I stocks are the least expensive to produce, and they currently account for abut 75 percent of all basestocks. These comprise the bulk of the "conventional" basestocks.

Groups II and III are the High Viscosity Index and Very High Viscosity Index basestocks. They are hydroprocessed mineral oils. The Group III oils contain less saturates and sulfur than the Group II oils and have higher viscosity indices than the Group II oils do. Groups II and III stocks perform better than the Group I basestocks do, particularly in measures of thermal and oxidative stability. Isodewaxing oils also belong to Groups II and III. Isodewaxing rids these mineral oils of a significant portion of their waxes, which improves their cold temperature performance greatly. Groups II and III stocks are more expensive to produce than Group I stocks are, and account for about 20 percent of all basestocks. These are the stocks that are squeezing the Group I "conventional" stocks out of the marketplace.

Group II and III stocks may be "conventional" or "unconventional": these marketing terms have no precise definitions. Generally, unconventional basestocks are mineral oils with unusually high viscosity indices and unusually low volatilities. Group II and III solvent refined mineral basestocks are "conventional. However, one producer calls its Group II hydrocracked isodewaxed basestock "unconventional" while another calls its Group II hydrocracked isodewaxed basestock "conventional" - because that producer has a Group III oil for which it reserves the label, "unconventional."

What About Groups IV and V?

Group IV includes polyalphaolefins (PAOs) (AMSOIL, MOBIL1). Group V includes all other basestocks not included in Groups I, II, III and IV. Esters are Group V basestocks (Red Line).

According to Lubes 'N' Greases (Nov. 1997), if basestocks were arranged in a performance pyramid, the Group I stocks would comprise the base, Groups II and III the middle and Group IV the pinnacle of performance. Group IV stocks, the PAOs, make up about 3 percent of the base oil market. (The Group V basestocks do not figure in the pyramid, presumably, because of the group's diversity, its small market share and wide range of performance.) Net Effect

The net effect of the changing marketplace is one of increasing lubricant quality. Compared to Group I solvent refined oils, hydroprocessed Group II and III oils offer lower volatility, and when properly additized, greater thermal and oxidative stability and lower pour points. Group IV oils offer superior volatility, thermal stability, oxidative stability and pour point characteristics to those of the Group II and III oils with less reliance on additives.

For consumers, that quality increase will bring oils with lower rates of oil consumption, longer drain capabilities and better performance in high and low temperature operations.

Even with an overall increase of motor oil quality as Group I stocks are phased out of the market, the differences between Group II and III oils and Group IV oils leaves a substantial margin for product differentiation.

"We [PAO manufacturers] design the desired molecular structure in advance, then manufacture to explicit specifications, Jim Willis, manager of Mobil Chemical's Beaumont, Texas facility told Lubes 'N' Greases (Nov. 1997). "And you have a base oil which is absolutely consistent from batch to batch and which provides certain performance properties - in low temperature starting and pumping (characteristics that a low pour point alone don't guarantee). Volatility, wear protection, improved fuel economy - that cannot be matched by base oil produced by either process, whether it's solvent refined or hydroprocessed."

The trend toward increasing motor oil quality will not be reversed. In fact, as environmental regulations grow increasingly strict, motor oil quality will have to increase even more. And while Group II and III basestocks provide better performance than Group I basestocks do, they have lower performance ceilings than Group IV stocks do. The future belongs to the Group IV basestocks (AMSOIL Synthetic Oils, MOBIL 1 are Group IV Polyalphaolefins).

Additives are important, but top quality basestocks are the key to a superior oil.

Also important to note: As we said group II and up stocks may be "conventional" or "unconventional" and these marketing terms have no precise definitions. That’s why manufacturers are basically free to call the product synthetic almost at their own will if the process includes one unconventional procedure. This small extra step can make the whole stock unconventional or in other words, synthetic. On the other hand, the base stock itself can be completely unconventional, or let’s say, truly synthetic (group IV and V). Then we can ask a very important question: If the stock is rally unconventional, then what is the percentage of this stock included in the oil itself. What is the percentage of let’s say advanced and expensive polyalphaolefins (PAOs) or polyol ester base included in the oil we pay so dearly for?

Oil Additive or Snakeoil Additive?

In recent years many companies have been introducing engine oil additives to the automotive repair market. Most of them give the impression that oil alone cannot give you the protection you need for today's engines. Although this may be true of petroleum based motor oils, it is, for the most part, not true of synthetics. If you want to protect your engines better and improve your fuel economy and performance, synthetic oils are definitely the way to go.

Oil additives, on the other hand, have been shown in many tests to give marginal performance and/or fuel economy improvements. Moreover, many oil additives have been shown to actually increase engine wear. In the final analysis, the question is: Do you want to waste your money on snakeoil or on the "real deal"?

The article that follows provides a very good analysis of what oil additives can do (or not do) to your engine. It was written by Fred Rau in Road Rider Magazine (now Motorcycle Consumer News) and is for informational purposes only. ROAD RIDER/August 1992/Pg 15

Information for this article was compiled from reports and studies by the University of Nevada Desert Research Center, DuPont Chemical Company, Avco Lycoming (aircraft engine manufacturers), North Dakota State University, Briggs and Stratton (engine manufacturers), the University of Utah Engineering Experiment Station, California State Polytechnic College and the National Aeronautics and Space Administration's Lewis Research Center.

Road Rider does not claim to have all the answers. Nor do we care to presume to tell you what to do. We have simply tried to provide you with all the information we were able to dredge up on this subject, in hopes it will help you in making your own, informed decision. You Can't Tell The Players Without A Program

On starting this project, we set out to find as many different oil additives as we could buy. That turned out to be a mistake. There were simply too many available! At the very first auto parts store we visited, there were over two dozen different brand names available. By the end of the day, we had identified over 40 different oil additives for sale and realized we needed to rethink our strategy. First of all, we found that if we checked the fine print on the packages, quite a number of the additives came from the same manufacturer. Also, we began to notice that the additives could be separated into basic "groups" that seemed to carry approximately the same ingredients and the same promises. In the end, we divided our additives into four basic groups and purchased at least three brands from three different manufacturers for each group.

We defined our four groups this way:

1. Products that seemed to be nothing more than regular 50-rated engine oil (including standard additives) with PTFE (Teflonд) added. 2. Products that seemed to be nothing more than regular 50-rated engine oil (including standard additives) with zinc dialkyldithiophosphate added. 3. Products containing (as near as we could determine) much the same additives as are already found in most major brands of engine oil, though in different quantities and combinations. 4. Products made up primarily of solvents and/or detergents. There may be some differences in chemical makeup within groups, but that is impossible to tell since the additive manufacturers refuse to list the specific ingredients of their products. We will discuss each group individually.

The PTFE Mystery

Currently, the most common and popular oil additives on the market are those that contain PTFE powders suspended in a regular, over-the-counter type, 50-rated petroleum or synthetic engine oil. PTFE is the common abbreviation used for Polytetrafloeraethylene, more commonly known by the trade name "Teflon," which is a registered trademark of the DuPont Chemical Corporation. Among those oil additives we have identified as containing PTFE are: Slick 50, Liquid Ring, Lubrilon, Microlon, Matrix, Petrolon (same company as Slick 50), QMI, and T-Plus (K-Mart). There are probably many more names in use on many more products using PTFE. We have found that oil additive makers like to market their products under a multitude of "private brand" names. While some of these products may contain other additives in addition to PTFE, all seem to rely on the PTFE as their primary active ingredient and all, without exception, do not list what other ingredients they may contain.

Though they have gained rather wide acceptance among the motoring public, oil additives containing PTFE have also garnered their share of critics among experts in the field of lubrication. By far the most damning testimonial against these products originally came from the DuPont Chemical Corporation, inventor of PTFE and holder of the patents and trademarks for Teflon. In a statement issued about ten years ago, DuPont's Fluoropolymers Division Product Specialist, J.F. Imbalzano said, "Teflon is not useful as an ingredient in oil additives or oils used for internal combustion engines." At the time, DuPont threatened legal action against anyone who used the name "Teflon" on any oil product destined for use in an internal combustion engine, and refused to sell its PTFE powders to any one who intended to use them for such purposes. After a flurry of lawsuits from oil additive makers, claiming DuPont could not prove that PTFE was harmful to engines, DuPont was forced to once again begin selling their PTFE to the additive producers.

The additive makers like to claim this is some kind of "proof' that their products work, when in fact it is nothing more than proof that the American legal ethic of "innocent until proven guilty" is still alive and well. The decision against DuPont involved what is called "restraint of trade." You can't refuse to sell a product to someone just because there is a possibility they might use it for a purpose other than what you intended it for. It should be noted that DuPont's official position on the use of PTFE in engine oils remains carefully aloof and noncommittal, for obvious legal reasons. DuPont states that though they sell PTFE to oil additive producers, they have "no proof of the validity of the additive makers' claims." They further state that they have "no knowledge of any advantage gained through the use of PTFE in engine oil." Fear of potential lawsuits for possible misrepresentation of a product seem to run much higher among those with the most to lose.

After DuPont's decision and attempt to halt the use of PTFE in engine oils, several of the oil additive companies simply went elsewhere for their PTFE powders, such as purchasing them in other countries. In some cases, they disguise or hype their PTFE as being something different or special by listing it under one of their own trade names. That doesn't change the fact that it is still PTFE. In addition, there is some evidence that certain supplies of PTFE powders (from manufacturers other than DuPont) are of a cruder version than the original, made with larger sized flakes that are more likely to "settle out" in your oil or clog up your filters. One fairly good indication that a product contains this kind of PTFE is if the instructions for its use advise you to "shake well before using." It only stands to reason that if the manufacturer knows the solids in his product will settle to the bottom of a container while sitting on a shelf, the same thing is going to happen inside your engine when it is left idle for any period of time.

The problem with putting PTFE in your oil, as explained to us by several industry experts, is that PTFE is a solid. The additive makers claim this solid "coats" the moving parts in an engine (though that is far from being scientifically proven). Slick 50 is currently both the most aggressive advertiser and the most popular seller, with claims of over 14 million treatments sold. However, such solids seem even more inclined to coat non-moving parts, like oil passages and filters. After all, if it can build up under the pressures and friction exerted on a cylinder wall, then it stands to reason it should build up even better in places with low pressures and virtually no friction. This conclusion seems to be borne out by tests on oil additives containing PTFE conducted by the NASA Lewis Research Center, which said in their report, "In the types of bearing surface contact we have looked at, we have seen no benefit. In some cases we have seen detrimental effect. The solids in the oil tend to accumulate at inlets and act as a dam, which simply blocks the oil from entering. Instead of helping, it is actually depriving parts of lubricant."

Remember, PTFE in oil additives is a suspended solid. Now think about why you have an oil filter on your engine. To remove suspended solids, right? Right. Therefore it would seem to follow that if your oil filter is doing its job, it will collect as much of the PTFE as possible, as quickly as possible. This can result in a clogged oil filter and decreased oil pres sure throughout your engine. In response to our inquiries about this sort of problem, several of the PTFE pushers responded that their particulates were of a sub-micron size, capable of passing through an ordinary oil filter unrestricted. This certainly sounds good, and may in some cases actually be true, but it makes little difference when you know the rest of the story. You see, PTFE has other qualities besides being a friction reducer: It expands radically when exposed to heat. So even if those particles are small enough to pass through your filter when you purchase them, they very well may not be when your engine reaches normal operating temperature. Here again, the scientific evidence seems to support this, as in tests conducted by researchers at the University of Utah Engineering Experiment Station involving Petrolon additive with PTFE. The Petrolon test report states, "There was a pressure drop across the oil filter resulting from possible clogging of small passageways."

In addition, oil analysis showed that iron contamination doubled after using the treatment, indicating that engine wear didn't go down - it appeared to shoot up. This particular report was paid for by Petrolon (marketers of Slick 50), and was not all bad news for their products. The tests, conducted on a Chevrolet six-cylinder automobile engine, showed that after treatment with the PTFE additive the test engine's friction was reduced by 13.1 percent. Also, output horsepower increased from 5.3 percent to 8.1 percent, and fuel economy improved from 11.8 percent under light load to 3.8 percent under heavy load. These are the kind of results an aggressive marketing company like Petrolon can really sink their teeth into. If we only reported the results in the last paragraph to you, you'd be inclined to think Slick 50 was indeed a magic engine elixir. What you have to keep in mind is that often times the benefits (like increased horse power and fuel economy) may be out weighed by some serious drawbacks... The Plot Thickens

Just as we were about to go to press with this article, we were contacted by the public relations firm of Trent and Company, an outfit with a prestigious address in the Empire State Building, New York. They advised us they were working for a company called QMI out of Lakeland, Florida, that was marketing a "technological breakthrough" product in oil additives. Naturally, we asked them to send us all pertinent information, including any testing and research data. What we got was pretty much what we expected. QMI's oil additive, according to their press release, uses "ten times more PTFE resins than its closest competitor." Using the "unique SX-6000 formula," they say they are the only company to use "aqueous dispersion resin which means the microns (particle sizes) are extensively smaller and can penetrate tight areas." This, they claim, "completely eliminates the problem of clogged filters and oil passages."

Intrigued by their press release, we set up a telephone interview with their Vice-President of Technical Services, Mr. Owen Heatwole. Mr. Heatwole's name was immediately recognized by us as one that had popped in earlier research of this subject as a former employee of Petrolon, a company whose name seems inextricably linked in some fashion or another with virtually every PTFE-related additive maker in the country. Mr. Heatwole was a charming and persuasive talker with a knack for avoiding direct answers as good as any seasoned politician. His glib pitch for his product was the best we've ever heard, but when dissected and pared down to the verifiable facts, it actually said very little. When we asked about the ingredients in QMI's treatments, we got almost exactly the response we expected. Mr. Heatwole said he would "have to avoid discussing specifics about the formula, for proprietary reasons." After telling us that QMI was being used by "a major oil company," a "nuclear plant owned by a major corporation" and a "major engine manufacturer," Mr. Heatwole followed up with, "Naturally, I can't reveal their names - for proprietary reasons." He further claimed to have extensive testing and research data available from a "major laboratory," proving conclusively how effective QMI was. When we asked for the name of the lab, can you guess? Yup, "We can't give out that information, for proprietary reasons."

What QMI did give us was the typical "testimonials," though we must admit theirs came from more recognizable sources than usual. They seem to have won over the likes of both Team Kawasaki and Bobby Unser, who evidently endorse and use QMI in their racing engines. Mr. Heatwole was very proud of the fact that their product was being used in engines that he himself admitted are "torn down and completely inspected on a weekly basis." Of course, what he left out is that those same engines are almost totally rebuilt every time they're torn down. So what does that prove in terms of his product reducing wear and promoting engine longevity? Virtually nothing. Mr. Heatwole declined to name the source of QMI's PTFE supply "for proprietary reasons." He bragged that their product is sold under many different private labels, but refused to identify those labels "for proprietary reasons."

When asked about the actual size of the PTFE particles used in QMI, he claimed they were measured as "sub-micron in size" by a "major motor laboratory" which he couldn't identify - you guessed it - for "proprietary reasons." After about an hour of listening to "don't quote me on this," "I'll have to deny that if you print it," and "I can't reveal that," we asked Mr. Heatwole if there was something we could print. "Certainly," he said, "Here's a good quote for you: 'The radical growth in technology has overcome the problem areas associated with PTFE in the 1980s'" "Not bad," we said. Then we asked to whom we might attribute this gem of wisdom. DuPont Chemical, perhaps? "Me," said Mr. Heatwole. "I said that." QMI's press releases like to quote the Guinness Book Of Records in saying that PTFE is "The slickest substance known to man." Far be it from us to take exception to the Guinness Book, but we doubt that PTFE is much slicker than some of the people marketing it. The Zinc Question

The latest "miracle ingredient" in oil additives, attempting to usurp PTFE's cure-all throne, is zinc dialkyldithiophosphate, which we will refer to here after as simply "zinc." Purveyors of the new zinc-related products claim they can prove absolute superiority over the PTFE-related products. Naturally, the PTFE crowd claim exactly the same, in reverse. Zinc is contained as part of the standard additive package in virtually every major brand of engine oil sold today, varying from a low volume of 0.10 per cent in brands such as Valvoline All Climate and Chevron l5W-50, to a high volume of 0.20 percent in brands such as Valvoline Race and Pennzoil GT Performance.

Organic zinc compounds are used as extreme pressure, anti-wear additives, and are therefore found in larger amounts in oils specifically blended for high-revving, turbocharged or racing applications. The zinc in your oil comes into play only when there is actual metal-to-metal contact within your engine, which should never occur under normal operating conditions. However, if you race your bike, or occasionally play tag with the redline on the tach, the zinc is your last line of defense. Under extreme conditions, the zinc compounds react with the metal to prevent scuffing, particularly between cylinder bores and piston rings. However - and this is the important part to remember - available research shows that more zinc does not give you more protection, it merely prolongs the protection if the rate of metal-to-metal contact is abnormally high or extended. So unless you plan on spending a couple of hours dragging your knee at Laguna Seca, adding extra zinc compounds to your oil is usually a waste. Also, keep in mind that high zinc content can lead to deposit formation on your valves, and spark plug fouling. Among the products we found containing zinc dialkyldithiophosphate were Mechanics Brand Engine Tune Up, K Mart Super Oil Treatment, and STP Engine Treatment With XEP2. The only reason we can easily identify the additives with the new zinc compounds is that they are required to carry a Federally mandated warning label indicating they contain a hazardous substance. The zinc phosphate they contain is a known eye irritant, capable of inflicting severe harm if it comes in contact with your eyes. If you insist on using one of these products, please wear protective goggles and exercise extreme caution.

As we mentioned, organic zinc compounds are already found in virtually every major brand of oil, both automotive and motorcycle. However, in recent years the oil companies voluntarily reduced the amount of zinc content in most of their products after research indicated the zinc was responsible for premature deterioration and damage to catalytic converters. Obviously this situation would not affect 99 percent of all the motorcycles on the road - however, it could have been a factor with the newer BMW converter - equipped bikes. Since the reduction in zinc content was implemented solely for the protection of catalytic converters, it is possible that some motorcycles might benefit from a slight increase in zinc content in their oils. This has been taken into account by at least one oil company, Spectro, which offers 0.02 to 0.03 percent more zinc compounds in its motorcycle oils than in its automotive oils. Since Spectro (Golden 4 brand, in this case) is a synthetic blend lubricant designed for extended drain intervals, this increase seems to be wholly justified. Also, available research indicates that Spectro has, in this case, achieved a sensible balance for extended application without increasing the zinc content to the point that it is likely to cause spark plug fouling or present a threat to converter-equipped BMW models. It would appear that someone at Spectro did their homework. Increased Standard Additives: More Is Not Necessarily Better

Though some additives may not contain anything harmful to your engine, and even some things that could be beneficial, most experts still recommend that you avoid their use. The reason for this is that your oil, as purchased from one of the major oil companies, already contains a very extensive additive package. This package is made up of numerous, specific additive components, blended to achieve a specific formula that will meet the requirements of your engine. Usually, at least several of these additives will be synergistic. That is, they react mutually, in groups of two or more, to create an effect that none of them could attain individually. Changing or adding to this formula can upset the balance and negate the protective effect the formula was meant to achieve, even if you are only adding more of something that was already included in the initial package. If it helps, try to think of your oil like a cake recipe. Just because the original recipe calls for two eggs (which makes for a very moist and tasty cake), do you think adding four more eggs is going to make the cake better? Of course not. You're going to upset the carefully calculated balance of ingredients and magnify the effect the eggs have on the recipe to the point that it ruins the entire cake. Adding more of a specific additive already contained in your oil is likely to produce similar results. This information should also be taken into account when adding to the oil already in your bike or when mixing oils for any reason, such as synthetic with petroleum. In these cases, always make sure the oils you are putting together have the same rating (SA, SE, SC, etc.). This tells you their additive packages are basically the same, or at least compatible, and are less likely to upset the balance or counteract each other.

Detergents And Solvents Many of the older, better-known oil treatments on the market do not make claims nearly so lavish as the new upstarts. Old standbys like Bardahl, Rislone and Marvel Mystery Oil, instead offer things like "quieter lifters," "reduced oil burning" and a "cleaner engine." Most of these products are made up of solvents and detergents designed to dissolve sludge and carbon deposits inside your engine so they can be flushed or burned out. Wynn's Friction Proofing Oil, for example, is 83 percent kerosene. Other brands use naphthalene, xylene, acetone and isopropanol. Usually, these ingredients will be found in a base of standard mineral oil. In general, these products are designed to do just the opposite of what the PTFE and zinc phosphate additives claim to do. Instead of leaving behind a "coating" or a "plating" on your engine surfaces, they are designed to strip away such things. All of these products will strip sludge and deposits out and clean up your engine, particularly if it is an older, abused one. The problem is, unless you have some way of determining just how much is needed to remove your deposits without going any further, such solvents also can strip away the boundary lubrication layer provided by your oil. Overuse of solvents is an easy trap to fall into, and one which can promote harmful metal-to-metal contact within your engine. As a general rule of thumb these products had their place and were at least moderately useful on older automobile and motorcycle engines of the Fifties and Sixties, but are basically unneeded on the more efficient engine designs of the past two decades.

The Infamous "No Oil" Demo

At at least three major motorcycle rallies this past year, we have witnessed live demonstrations put on to demonstrate the effectiveness of certain oil additives. The demonstrators would have a bench-mounted engine which they would fill with oil and a prescribed dose of their "miracle additive." After running the engine for a while they would stop it, drain out the oil and start it up again. Instant magic! The engine would run perfectly well for hours on end, seemingly proving the effectiveness of the additive which had supposedly "coated" the inside of the engine so well it didn't even need the oil to run. In one case, we saw this done with an actual motorcycle, which would be ridden around the parking lot after having its oil drained. A pretty convincing demonstration - until you know the facts.

Since some of these demonstrations were conducted using Briggs and Stratton engines, the Briggs and Stratton Company itself decided to run a similar, but somewhat more scientific, experiment. Taking two brand-new, identical engines straight off their assembly line, they set them up for bench-testing. The only difference was that one had the special additive included with its oil and the other did not. Both were operated for 20 hours before being shut down and having the oil drained from them. Then both were started up again and allowed to run for another 20 straight hours. Neither engine seemed to have any problem performing this "minor miracle." After the second 20-hour run, both engines were completely torn down and inspected by the company's engineers. What they found was that both engines suffered from scored crankpin bearings, but the engine treated with the additive also suffered from heavy cylinder bore damage that was not evident on the untreated engine. This points out once again the inherent problem with particulate oil additives: They can cause oil starvation. This is particularly true in the area of piston rings, where there is a critical need for adequate oil flow. In practically all of the reports and studies on oil additives, and particularly those involving suspended solids like PTFE, this has been reported as a major area of engine damage. The Racing Perspective

Among the most convincing testimonials in favor of oil additives are those that come from professional racers or racing teams. As noted previously, some of the oil additive products actually are capable of producing less engine friction, better gas mileage and higher horsepower out put. In the world of professional racing, the split-second advantage that might be gained from using such a product could be the difference between victory and defeat. Virtually all of the downside or detrimental effects attached to these products are related to extended, long-term usage. For short-life, high-revving, ultra-high performance engines designed to last no longer than one racing season (or in some cases, one single race), the long-term effects of oil additives need not even be considered. Racers also use special high-adhesion tires that give much better traction and control than our normal street tires, but you certainly wouldn't want to go touring on them, since they're designed to wear out in several hundred (or less) miles. Just because certain oil additives may be beneficial in a competitive context is no reason to believe they would be equally beneficial in a touring context.

The Best of The Worst

Not all engine oil additives are as potentially harmful as some of those we have described here. However, the best that can be said of those that have not proved to be harmful is that they haven't been proved to offer any real benefits, either. In some cases, introducing an additive with a compatible package of components to your oil in the right proportion and at the right time can conceivably extend the life of your oil. However, in every case we have studied it proves out that it would actually have been cheaper to simply change the engine oil instead. In addition, recent new evidence has come to light that makes using almost any additive a game of Russian Roulette. Since the additive distributors do not list the ingredients contained within their products, you never know for sure just what you are putting in your engine. Recent tests have shown that even some of the most inoffensive additives contain products which, though harmless in their initial state, convert to hydrofluoric acid when exposed to the temperatures inside a firing cylinder. This acid is formed as part of the exhaust gases, and though it is instantly expelled from your engine and seems to do it no harm, the gases collect inside your exhaust system and eat away at your mufflers from the inside out. Whatever The Market Will Bear

The pricing of oil additives seems to follow no particular pattern whatsoever. Even among those products that seem to be almost identical, chemically, retail prices covered an extremely wide range. For example: One 32-ounce bottle of Slick 50 (with PTFE) cost us $29.95 at a discount house that listed the retail price as $59.95, while a 32-ounce bottle of T-Plus (which claims to carry twice as much PTFE as the Slick 50) cost us only $15.88. A 32-ounce bottle of STP Engine Treatment (containing what they call XEP2), which they claim they can prove "outperforms leading PTFE engine treatments," cost us $17.97. Yet a can of K Mart Super Oil Treatment, which listed the same zinc-derivative ingredient as that listed for the XEP2, cost us a paltry $2.67. Industry experts estimate that the actual cost of producing most oil additives is from one-tenth to one-twentieth of the asking retail price. Certainly no additive manufacturer has come forward with any exotic, high-cost ingredient or list of ingredients to dispute this claim. As an interesting note along with this, back before there was so much competition in the field to drive prices down, Petrolon (Slick 50) was selling their PTFE products for as much as $400 per treatment! The words "buyer beware" seem to take on very real significance when talking about oil additives.

The Psychological Placebo

You have to wonder, with the volume of evidence accumulating against oil additives, why so many of us still buy them. That's the million-dollar question, and it's just as difficult to answer as why so many of us smoke cigarettes, drink hard liquor or engage in any other number of questionable activities. We know they aren't good for us - but we go ahead and do them anyway. Part of the answer may lie in what some psychiatrists call the "psychological placebo effect." Simply put, that means that many of us hunger for that peace of mind that comes with believing we have purchased the absolute best or most protection we can possibly get. Even better, there's that wonderfully smug feeling that comes with thinking we might be a step ahead of the pack, possessing knowledge of something just a bit better than everyone else. Then again, perhaps it comes from an ancient, deep-seated need we all seem to have to believe in magic. There has never been any shortage of unscrupulous types ready to cash in on our willingness to believe that there's some magical mystery potion we can buy to help us lose weight, grow hair, attract the opposite sex or make our engines run longer and better. I doubt that there's a one of us who hasn't fallen for one of these at least once in our lifetimes. We just want it to be true so bad that we can't help ourselves. Testimonial Hype vs. Scientific Analysis

In general, most producers of oil additives rely on personal "testimonials" to advertise and promote their products. A typical print advertisement will be one or more letters from a satisfied customer stating something like, "1 have used Brand X in my engine for 2 years and 50,000 miles and it runs smoother and gets better gas mileage than ever before. I love this product and would recommend it to anyone." Such evidence is referred to as "anecdotal" and is most commonly used to promote such things as miracle weight loss diets and astrology. Whenever I see one of these ads I am reminded of a stunt played out several years ago by Allen Funt of "Candid Camera" that clearly demonstrated the side of human nature that makes such advertising possible. With cameras in full view, fake "product demonstrators" would offer people passing through a grocery store the opportunity to taste-test a "new soft drink." What the victims didn't know was that they were being given a horrendous concoction of castor oil, garlic juice, Tabasco sauce and several other foul-tasting ingredients. After taking a nice, big swallow, as instructed by the demonstrators, the unwitting victims provided huge laughs for the audience by desperately trying to conceal their anguish and disgust. Some literally turned away from the cameras and spit the offending potion on the floor.

What Does Motor Oil Do?

The type of driving you do, the climate in which you live, and the age of the vehicle, the manufacturer's recommendations all have a bearing on the type of oil you should be using. An added factor in your car/truck's life and performance is related to how you handle the most routine aspect of any vehicle's maintenance - the frequency of oil changes or, more importantly, THE TYPE OF OIL YOU USE! Yes, it DOES make a difference!

What Is An Oil's Job?

The biggest responsibility of any oil is to form a layer between metal surfaces of various engine parts, in a transmission or in the differentials. This layer is what provides the lubrication characteristics of any oil.

Oil serves as a sealant, filling the microscopic ridges and valleys found in any metal surface, increasing the engine's efficiency.

Oil must serve as a cleaning function, carrying away dirt or other debris which damages bearings or other parts which operate in tight tolerances. Debris is removed through the engine oil filter or the transmission filter. Oil uses detergent additives to combat combustion by-products. Burning gasoline (or diesel fuel) produces acids, moisture, soda, ash and other contaminants. The detergent fights these by-products, inhibiting their buildup as sludge, varnishes, etc.

Oil is a tremendous coolant. In the engine, the oil cools the underside of the pistons, valve springs, camshaft, rods, crankshaft and bearings. The oil picks up the heat from the combustion of fuel, as well as friction, and takes it away (no matter how good the oil may be, there is always friction). The volume of the oil in the crankcase helps transfer the heat, but where a car/truck is used in high temperature climates, for hauling trailers or heavy loads, an engine oil cooler is sometimes recommended.

By using 100% Synthetic Oil the engine will remain COOL even in the harshest conditions. It will cause the average engine to operate 30 degrees to 50 degrees cooler than normal!!! That could very likely eliminate the need for an oil cooler altogether.

Oil is the only coolant in your automatic transmission. There's a small radiator within the engine's radiator to take the heat away. When your vehicle is used in high temperature climates, hauling trailers or heavy loads, synthetic ATF is highly recommended.

The type and condition of the oil chosen is important. Oil comes in a wide variety of ratings and viscosities, designed for particular applications or vehicle age. With so many choices, a car/truck owner has to know the proper viscosity and API rating recommended for his particular vehicle.

Matching Oil to the Way You Drive:

While you drive, you subject your engine to varying conditions, including:

Stop and go driving in town at low speeds Constant high speed freeway driving Very High temperatures Very low temperatures Varying loads

Each puts stress on your car/truck's engine oil. In fact, just starting the engine places extreme stress on the engine's oil, especially in winter weather.

The next time you change your oil, take a minute and think about the following: how you drive, the conditions you encounter - on the street or highway - and the environments your car or truck operates in. Do you do mostly stop and go driving, or is it mostly open freeway driving? Is the outside temperature very hot, or very cold? Do you frequently tow trailers or haul heavy loads? Is your vehicle an older model, with lots of miles, or a newer model?

The way you define your driving habits, environment and the loads you haul or tow, plus the age of your car or truck, will help determine which type and grade of oil you select. No matter what conditions you encounter, 100% Synthetic Oil offers you the right combination of premium engine oils to give your car/truck's engine the proper protection it needs. It can protect you from what is called: "Dry Engine Start-Up"! It always leaves a film of oil on surfaces preventing "metal to metal wear" during cold starts!

Viscosity:

One of the main areas of concern of any car/truck owner is the viscosity of the oil. The term "weight" has been applied to viscosity for a number of years, but it has nothing to do with how much the oil weighs. On any oil container, the viscosity is clearly marked, with numbers like SAE 0W-30 5W-30, 10W-40, 20W-50, etc.

What do the numbers mean?

Viscosity is defined as the physical property of any fluid to resist flow when pressure is applied. The Society of Automotive Engineers (SAE) uses a numbering system to represent an oil's viscosity at a specific temperature. The higher the number, the more resistant it is to flow. The lower the number, the easier it flows. This allows you to make an "apples to apples" comparison of various oils.

Engine oils must operate in very difficult environments, plus perform a number of important tasks:

It must flow easily at temperature well below zero. It must supply lubrication at very high temperatures (in excess of 250°F).

Lower viscosity oils flow well at very low temperatures, they are the choice for severe winter operation. Obviously, the ability to flow readily is critical to start your vehicle's engine in brutal cold, and calls for a lower viscosity, such as 0W or 5W viscosity grade.

For protection against high engine operating temperatures, oil must be able to function and provide the needed lubrication. When the vehicle is operating in summer heat, with temperatures above 80 to 90 degrees day after day, the need is for a high viscosity oil.

But do you want to change grades of oil every time the weather gets warmer or colder? Probably not. This is why there are engine oils with two viscosities on the market, known as "multi-viscosity" oils. These oils carry the low temperature flow, and high temperature lubrication properties of the two oils, such as a 0W-30. The "W" refers to winter, with a special additive package to give better cold weather starting performance. As an example, under high heat, OW-30 will have the same flow characteristics as a 10W-30 because their "high numbers" are the same.

Synthetic Oils will handle both the high heat of the Desert Southwest or the cold cranking demanded in Alaska! Many of them have pour points are as low as 76 degrees BELOW Zero!

The issue of engine oil volatility is an important one to every car or truck owner, yet few know about it. Volatility is related to viscosity. Volatility is defined as the characteristic of liquids to become a vapor when heat is applied. A liquid is said to have "high" volatility if it tends to evaporate when heat is applied, and "low" volatility if it tends to remain a liquid when the same amount of heat is applied.

To meet the federal government's fuel mileage standards, auto makers tell owners to use lower viscosity oils. Unfortunately, low viscosity oils tend to evaporate more easily than high viscosity oils. The problem: Using a low viscosity oil generally leads to what appears to be an oil consumption problem, when actually the problem is evaporation - the most fuel efficient oils evaporate most readily.

Potential Problem Areas

Oil Consumption: More volatile oils mean higher oil consumption; less volatile oils mean less oil consumption.

Starting Friction: If the lighter parts of the oil evaporate, the remaining oil will not provide the proper low temperature starting characteristics.

Engine Deposits: An oil in a vapor state is more likely to decompose, forming harmful deposits (varnish, sludge), than oil in a liquid state.

Heat Stress: Less oil in the pan results in higher engine temperatures. Higher oil temperatures lead to greater evaporation, more oxidation, more deposits and shorter engine life.

Engine Wear: If the oil thickens, greater wear will occur on starting. The oil's anti-wear additives will be used to fight oxidation, rather than prevent wear. Additives:

An additive package aids in improving the oil's life. Remember, nothing lasts forever. Additives are like the oil they help - they have a limited life. Because of the quality of additives, Lubricants can far exceed the extended drain intervals!

Some of the additives are:

Detergents: Keep high temperature engine parts, such as pistons and rings, clean and free from deposits.

Dispersants: Suspend and disperse materials that could form varnishes, sludge, etc., clogging the engine.

Anti-wear: Gives added film strength to prevent wear of heavily loaded surfaces (like the crankshaft's rod and main bearings).

Friction Modifiers: Reduce friction losses throughout the engine for more power and better fuel mileage.

Corrosion Inhibitors: Fight the rust and wear caused by acids and moisture. They protect vital steel or iron parts from rust, and corrosion of other metals.

Oxidation Inhibitors: Oxygen can combine with oil (even the best ones) at high engine temperatures to form damaging materials. These additives reduce thickening of the oil, and sludge formation.

Foam Inhibitors: The spinning of the crankshaft and the rods introduces great air turbulence in the crankcase, causing oil to form bubbles (foam). These additives limit bubble growth and break them up quickly. This keeps foam levels low, allowing the oil pump to circulate oil, not oil and air, through the engine.

Viscosity Index (VI) Improver: A VI Improver adds to oil's natural tendency to fight viscosity change with temperature variations. Because of the way synthetics are constructed (that's right, CONSTRUCTED) many of oils DO NOT NEED VI IMPROVERS! It is already built into the Synthetic Base Stock!

Pour Point Depressant: This additive improves a winter oil's ability to flow at very low temperatures. This is not really needed in true synthetic oil because the inherent ability of synthetic base stocks to flow in cold conditions (remember, in many instances as low as 76 degrees below zero!). Service Class:

The Owner's Manual for your car/truck will specify which API Service rating you must use to meet the warranty requirements, depending on whether your engine is a gasoline engine or a diesel. Gasoline engine oils are designated with SG or SH (and now, SJ). Diesel engine oil is designated with CD, CD-II, CE, CF, CF-2, CF-4, or CG-4. Some oils are rated for both gasoline and diesel applications, others are not. For example, an oil with a designation of SJ/CG-4 may be used in both gasoline and diesel engines in light trucks.

The SJ rating is the most current, with the most sophisticated additive packages to combat the effects discussed above. This service designation can replace all oils designated SC to SH. For diesels, ratings are based upon service applications. The latest is CG-4, which can be used to replace all other (except CF-2 and CD-II, a two-cycle diesel engine oil). If you have a question, I can assist you with getting the right service and viscosity ratings. When in doubt, a good rule of thumb is: Go with the best-the SJ rating (gasoline engines). When to Change Oil:

When using a petroleum oil, generally oil change intervals should not be extended beyond 5,000 miles. With the high stress applied to the lubricants in today's high temperature, high performance engines, petroleum oils begin to break down almost immediately. If I was using a conventional petroleum oil in my vehicle, I would probably change it every 3,000 miles.

Synthetic Oils Beat Petroleum Oils On All Counts!

Oil is the lifeblood of your vehicle's engine. Without it, there is little likelihood that any of your vehicles would make it past the end of our street each morning. For decades conventional petroleum oils have been providing adequate protection for all of our vehicles. Notice the key word here: adequate. Petroleum oils, for the most part, have done an adequate job of protecting our engines from break down. If you change it often enough, you can be relatively sure that your car will last 100,000 to 150,000 miles without a serious engine problem.

My question is this: Why are you settling for adequate when something better has been available for the past 25 years? Do you ask your mechanic to simply keep your vehicle from breaking down, or do you want him/her to keep it running in tip-top shape? The fact that you are reading this article suggests the latter. It is perfectly reasonable to expect top performance from your vehicles. You are certainly paying for it. It's tough to buy a vehicle for less than $15,000 to $20,000 anymore. That's a great deal of money to shell out for adequate performance.

Today's engines are built for better performance, and, although petroleum oils are designed for better performance today than they were 10 or 20 years ago, there is only so much that can be done. Today's engines need high performance lubricants, and synthetics are the only ones that fit the bill.

Why Petroleum Oils are Insufficient

Conventional petroleum oils are insufficient for use in today's vehicles primarily because they are a refined substance. Unfortunately, no refining process is perfect. Impurities will always remain when any refining process is done. Thus, there are many components of petroleum oils which are completely unnecessary for protecting your engine. They do absolutely nothing to lubricate your engine. In fact, there are even some components of petroleum oils which are actually harmful to your engine.

Prone to Break Down

Some of the chemicals in conventional lubricants break down at temperatures within the normal operating range of many vehicle and equipment components. Others are prone to break down in these relatively mild temperatures only if oxygen is present. But, this is invariably the case anyway. These thermally and oxidatively unstable contaminants do absolutely nothing to aid in the lubrication process. They are only present in conventional petroleum oils because removing them would be impossible or excessively expensive.

When thermal or oxidative break down of petroleum oil occurs, it leaves engine components coated with varnish, deposits and sludge. In addition, the lubricant which is left is thick, hard to pump and maintains little heat transfer ability.

Poor Cold Temperature Start-ups

Petroleum lubricants are also likely to contain paraffins which thicken dramatically in cold temperatures. As a result, petroleum lubricants will not readily circulate through your engine's oil system during cold weather. This may leave engine parts unprotected for as long as five minutes after startup! Obviously, significant wear can occur during this time frame.

Marginal Heat Control

Even when all conditions are perfect for conventional oils to do their job, they still don't do it all that well. Part of the problem is that (because of their refined nature) petroleum oils are composed of molecules which vary greatly in size. As the oil flows through your vehicle's lubrication system, the small, light molecules tend to flow in the center of the oil stream while the large, heavy ones adhere to metal surfaces where they create a barrier against heat movement from the component to the oil stream. In effect, the large, heavy molecules work like a blanket around hot components.

There is another effect of the non-uniformity of petroleum oil molecules which reduces their effectiveness as well. Uniformly smooth molecules slip over one another with relative ease. This is not the case with molecules of differing size. It would be much like putting one layer of marbles on top of another. If the marbles were all of the same size, they would move over one another fairly easily. However, if they were all of differing sizes, the result would be much less efficient. In the case of petroleum oils this inefficiency leads, ironically, to added friction in the system (the very thing that lubricants are supposed to reduce). Hence, petroleum oils are only marginally capable of controlling heat in your engine. Maybe Adequate is OK for You

Once again, I would like to state that petroleum oils ARE adequate for the purpose of protecting your engine. Under normal circumstances, most vehicles lubricated with petroleum oil should run satisfactorily for 100,000 to 150,000 miles without serious incidence. However, in order to achieve this life expectancy it will be imperative that you change your oil every 3,000 to 5,000 miles religiously.

So, if you like the hassle of changing your oil regularly and you are only looking for marginal performance for the next 100,000 miles, feel free to use petroleum oils. By the way, if you're interested, I've got an old dishwasher for sale too. You have to rinse your dishes first, it's really loud and runs for about 3 hours, but it gets most of the food off of our plates. It's a steal at only $50. Let me know if you're interested.

However, if you aren't all that fond of pulling dirty dishes out of your dishwasher, I'm going to assume that you don't relish the idea of changing your oil every 3,000 miles or dealing with another pushy car salesman every 3 to 5 years either. If that's true, keep reading. I think you're going to like this.

Synthetic Oils Simply Perform Better

There are five main areas where synthetic oils surpass their petroleum counterparts:

Oil drains can be extended Vehicle life can be extended Costly repairs can be reduced Fuel mileage can be improved Performance can be improved

Synthetic lubricant molecules are pure and of uniform size. This is because synthetic oils are designed from the ground up with the sole purpose of protecting your engine. Nothing is added if it does not significantly contribute to the lubricating ability of the oil. In addition, in top-quality synthetics, no component is added which is contaminated with any substance that might lessen the lubricating qualities of the oil. Not only that, synthetic oils are designed so that the molecules are of uniform size and weight. This significantly adds to the lubricating qualities of the oil. Extended Oil Drains

Heat and oxidation are the main enemies of lubricant basestocks - especially of the contaminants in conventional basestocks. Once a lubricant has begun to break down, it must be replaced so that the vehicle is not damaged by lack of lubrication or chemical attack. However, since synthetic oils are designed from pure, uniform synthetic basestocks, they contain no contaminants or unstable molecules which are prone to thermal and oxidative break down.

Moreover, because of their uniform molecular structure, synthetic lubricants operate with less friction than petroleum oils which have the non-uniform molecular structure discussed earlier. The result is better heat control, and less heat means less stress to the lubricant. Thus, synthetic oils can be used safely for much longer drain intervals than conventional lubricants. In fact, synthetic oils have been guaranteed for 25,000 miles or one year since 1972 for AMSOIL. Red Line Oil recommends long drain intervals of 10,000 to 18,000 miles.

You might ask why other synthetic oil manufacturers are not recommending extended oil drains for their synthetics. The answer is really very simple: money. They are afraid that if they recommend longer drain intervals, they won't sell enough oil - petroleum oil, that is.

You see, petroleum oil is their golden goose, and has been for years. The only reason large oil companies produce a synthetic oil is because somebody else did it first (AMSOIL), and they must please the small (but growing) percentage of the population which has already decided that synthetics are better and won't purchase anything else.

Petroleum oil is where the money is. With recommended oil drains of only 3,000 miles, many people are changing their oil 5 to 8 times per year. If everyone suddenly switched over to synthetics, they would begin to realize that it is possible to go 10,000 to 25,000 miles or more without an oil change (depending upon the oil). This is a scary thought for large oil companies who depend upon regular oil changes for their business. Extended Vehicle Life With Fewer Repairs

HEAT REDUCTION

More often than not, vehicle life is determined by engine life. One of the major factors affecting engine life is component wear and/or failure, which is often the result of high temperature operation. The uniformly smooth molecular structure of synthetic oils gives them a much lower coefficient of friction (they slip more easily over one another causing less friction) than petroleum oils. Less friction, of course, means less heat in the system. And, since heat is a major contributor to engine component wear and failure, synthetic oils significantly reduce these two detrimental effects.

In addition, because of their uniform molecular structure, synthetic oils do not cause the "blanket effect" which was mentioned earlier. Since each molecule in a synthetic oil is of uniform size, each is equally likely to touch a component surface at any given time, thus moving a certain amount of heat into the oil stream and away from the component. This makes synthetic oils far superior heat transfer agents than conventional petroleum oils.

ENGINE DEPOSIT REDUCTION

In discussing some of the pitfalls of petroleum oil use, engine cleanliness was an issue. Petroleum oils tend to leave sludge, varnish and deposits behind after thermal and oxidative break down. This leads to a significant reduction in engine performance and engine life as well as increasing the number of costly repairs that are necessary. Since synthetic oils have far superior thermal and oxidative stability than petroleum oils, they leave engines varnish, deposit and sludge-free.

COLD TEMPERATURE FLUIDITY

Synthetic oils and other lubricants do not contain paraffins or other waxes which dramatically thicken petroleum oils during cold weather. As a result, they tend to flow much better during cold temperature starts and begin lubricating an engine almost immediately. This leads to significant engine wear reduction, and, therefore, longer engine life and fewer costly repairs. Improved Fuel Mileage and Performance

As indicated earlier, synthetic oils, because of their uniform molecular structure, are tremendous friction reducers. It has already been stated that this is crucial to extending engine life, but it must also be mentioned that less friction leads to increased fuel economy and improved engine performance. Of course, logic points in that direction anyway. Any energy released from the combustion process that would normally be lost to friction can now be transferred directly to the wheels, providing movement. Vehicle acceleration becomes swifter and more powerful while using less fuel in the process.

The uniform molecular structure of synthetic oils has another performance enhancing benefit as well. In a petroleum oil, lighter molecules tend to boil off easily, leaving behind much heavier molecules which are difficult to pump. Certainly, the engine looses more energy pumping these heavy molecules than if it were pumping lighter ones. Since synthetic oils have more uniform molecules, fewer of these molecules tend to boil off. Moreover, when they do, the molecules which are left are of the same size and pumpability is not affected. Obviously, the end result is little loss of fuel economy or performance. Those Who Know, Agree

According to a technical paper (850564.1985) by the Society of Automotive Engineers, "Laboratory engine dynamometer, vehicle chassis rolls and over-the-road field tests confirm the outstanding performance capabilities for optimized synthetic engine oils in passenger car diesel as well as gasoline engines, including severe turbocharged models...Vehicle testing under severe and extended drain conditions demonstrates the performance reserve available with these synthetic engine oils. In addition to excellent protection against critical high-temperature piston deposits, ring sticking, overall engine cleanliness and wear, these synthetic oils offer fuel savings and superior low temperature fluidity."

In 1989, Mechanical Engineering Transactions had this to say in its 1989 Synthetic versus Mineral Fluids in Lubrication article: "Oil drain intervals in both industrial and automotive applications can be extended typically by a factor of four due to the improved oxidative stability of appropriately additized synthetics." It's Your Choice

Ultimately, it does not matter what we say. You have to decide how important these factors are to you. If you don't mind changing your oil every 3,000 miles and you'd purchase a new vehicle every 2 or 3 years regardless of its condition, maybe you don't need synthetics. Of course, the fuel savings and performance may still make the switch worth it. However, once again, the determination of whether to convert your vehicle over to synthetics can only be based on the relative importance that you place on any of these benefits.

If these benefits are of importance to you, don't settle for adequate anymore. Step up to the ultimate in protection, synthetics. Better yet, don't just use a synthetic, use the synthetic manufactured by the largest, most experienced synthetic lubrication company in the world. More Than You Ever Wanted to Know About Motor Oil

Choosing the best motor oil is a topic that comes up frequently in discussions between motoheads, whether they are talking about motorcycles or cars. The following article is intended to help you make a choice based on more than the advertising hype.

Oil companies provide data on their oils most often referred to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base.

This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc.

Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of shearing stress dependent on flow, and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm.

What many inexperienced people tend to forget is that along with anticipated temperature viscosity selection should also be based on engine specific technical specs. It must includes clearances in cold and hot condition (relative extension of valves is one of the major considerations), time it takes to warm up, RPM, max and min, diameter of oil passages, type and diameter and productivity of the filter and many other parameters. There is always trade off involved here. As an example of what designer faces consider that engine includes many mechanisms and operates in very wide range of temperatures. General rule all mechanical engineers follow is the faster mechanism works the more liquid lubricant is used to keep up with surfaces to fill gaps. On the other hand, the more load is present, the more viscose oil should be. On the other hand what is the point to have heavy weight oil if it cannot keep up leading to break in oil film, which will result in metal-to-metal contact? Just imagine how would behave heavy grease in fast turning turbine. Obviously it won’t work at all and that’s why turbine oil is very light. Low speed heavy load trucks tend to have heavy weight oil in them and small high rpm light duty engines will best work on light oils providing long engine life. Just put 5W__ engine oil in the car that recommends 10W as preferred and you will hear valve noise during warm up period. That’s because valves are cold and much shorter than hot valves. We have extra clearances between valves and cams that result in extra noise when oil film is thin and does not provide enough dumping and protection. You are experiencing extra wear here, but if temperature really drops below certain point, you do not have much choice. We have to sacrifice and at least to deliver oil to moving parts… Do you get the idea yet? Even designer of the engine now rely on the computer to optimize oil for the engine giving various weights to different criteria. It is just too many parameters to take in to account all of them and not to forget single one of them. That’s why it is important follow manufacturer specification for preferable oil for particular temperature.

The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use.

The following chart shows the relationship of "real" viscosity to their S.A.E. assigned numbers. The relationship of gear oils to engine oils is also shown.

_____________________________________________ __________________

| |

| SAE Gear Viscosity Number |

| _____________________________________________ ___________ |

| |75W |80W |85W| 90 | 140 | |

| |____|_____|___|______________|______________ __________| |

| |

| SAE Crank Case Viscosity Number |

| ____________________________ |

| |10| 20 | 30 | 40 | 50 | |

| |__|_____|____|_____|______| |

_____________________________________________ _________________

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42

viscosity cSt @ 100 degrees C

Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.

Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40, and 5W-30 require a lot of polymers (real synthetics excluded) to achieve that range. Some synthetics (not really synthetics based, but rather hydro processed oils) use a lot of polymers. Look carefully on 5W-50, 5W-40 by Castrol and Shell "Synthetics” which are actually hydro processed oils and both are use mineral oil based stock from Shell. In most cases high polymer content you can see right away in %ash column. That's what will be left in you engine (cylinders, valves oil channels) after oil circulate there and some burn in combustion chamber. It sure forms more sludge and deposits in the engine. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best.

Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. AMSOIL can formulate their 10W-30 and 15W-40 with no viscosity index improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no viscosity improvers in their 5W-30, and I assume the new 10W-30. Follow your manufacturer's recommendations as to which weights are appropriate for your vehicle.

Viscosity Index is an empirical number indicating the rate of change in viscosity of an oil within a given temperature range. Higher numbers indicate a low change, lower numbers indicate a relatively large change. The higher the number the better. This is one major property of an oil that keeps your bearings happy. These numbers can only be compared within a viscosity range. It is not an indication of how well the oil resists thermal breakdown.

Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better. 400 F is the minimum to prevent possible high consumption. Flash point is in degrees F.

Pour point is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. This measurement is especially important for oils used in the winter. A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain adequate oil pressure. This was not given by a lot of the manufacturers, but seems to be about 20 degrees F above the pour point. The lower the pour point the better. Pour point is in degrees F.

% sulfated ash is how much solid material is left when the oil burns. A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content.

% zinc is the amount of zinc used as an extreme pressure, anti- wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling.

The Data: Listed alphabetically ("---" indicates the data was not available)

Brand VI Flash Pour zinc

20W-50

AMSOIL (old) 136 482 -38 <.5 ---

AMSOIL (new) 157 507 -44 --- ---

Castrol GTX 122 440 -15 .85 .12

Exxon High Performance 119 419 -13 .70 .11

Havoline Formula 3 125 465 -30 1.0 ---

Kendall GT-1 129 390 -25 1.0 .16

Pennzoil GT Perf. 120 460 -10 .9 ---

Quaker State Dlx. 155 430 -25 .9 ---

Red Line 150 503 -49 --- ---

Shell Truck Guard 130 450 -15 1.0 .15

Spectro Golden 4 174 440 -35 --- .15

Spectro Golden M.G. 174 440 -35 --- .13

Unocal 121 432 -11 .74 .12

Valvoline All Climate 125 430 -10 1.0 .11

Valvoline Turbo 140 440 -10 .99 .13

Valvoline Race 140 425 -10 1.2 .20

Valvoline Synthetic 146 465 -40 <1.5 .12

20W-40

AMSOIL 124 50 -49 --- ---

Castrol Multi-Grade 110 440 -15 .85 .12

Quaker State 121 415 -15 .9 ---

15W-50

Chevron 204 415 -18 .96 .11

Mobil 1 170 470 -55 --- ---

Mystic JT8 144 420 -20 1.7 .15

Red Line 152 503 -49 --- ---

5W-50

Castrol Syntec 180 437 -45 1.2 .10

Quaker State Synquest 173 457 -76 --- ---

Pennzoil Performax 176 --- -69 --- ---

5W-40

Havoline 170 450 -40 1.4 ---

15W-40

AMSOIL (old) 135 460 -38 <.5 ---

AMSOIL (new) 164 462 -49 --- ---

Castrol 134 415 -15 1.3 .14

Chevron Delo 400 136 421 -27 1.0 ---

Exxon XD3 --- 417 -11 .9 .14

Exxon XD3 Extra 135 399 -11 .95 .13

Kendall GT-1 135 410 -25 1.0 .16

Mystic JT8 142 440 -20 1.7 .15

Red Line 149 495 -40 --- ---

Shell Rotella w/XLA 146 410 -25 1.0 .13

Valvoline All Fleet 140 --- -10 1.0 .15

Valvoline Turbo 140 420 -10 .99 .13

10W-30

AMSOIL (old) 142 480 -70 <.5 ---

AMSOIL (new) 162 520 -76 --- ---

Castrol GTX 140 415 -33 .85 .12

Chevron Supreme 150 401 -26 .96 .11

Exxon Superflo Hi Perf 135 392 -22 .70 .11

Exxon Superflo Supreme 133 400 -31 .85 .13

Havoline Formula 3 139 430 -30 1.0 ---

Kendall GT-1 139 390 -25 1.0 .16

Mobil 1 160 450 -65 --- ---

Pennzoil PLZ Turbo 140 410 -27 1.0 ---

Quaker State 156 410 -30 .9 ---

Red Line 139 475 -40 --- ---

Shell Fire and Ice 155 410 -35 .9 .12

Shell Super 2000 155 410 -35 1.0 .13

Shell Truck Guard 155 405 -35 1.0 .15

Spectro Golden M.G. 175 405 -40 --- ---

Unocal Super 153 428 -33 .92 .12

Valvoline All Climate 130 410 -26 1.0 .11

Valvoline Turbo 135 410 -26 .99 .13

Valvoline Race 130 410 -26 1.2 .20

Valvoline Synthetic 140 450 -40 <1.5 .12

5W-30

AMSOIL (old) 168 480 -76 <.5 ---

AMSOIL (new) 186 464 -76 --- ---

Castrol GTX 156 400 -35 .80 .12

Chevron Supreme 202? 354 -46 .96 .11

Chevron Supreme Synt. 165 446 -72 1.1 .12

Exxon Superflow HP 148 392 -22 .70 .11

Havoline Formula 3 158 420 -40 1.0 ---

Mobil 1 165 445 -65 --- ---

Mystic JT8 161 390 -25 .95 .1

Quaker State 165 405 -35 .9 ---

Red Line 151 455 -49 --- ---

Shell Fire and Ice 167 405 -35 .9 .12

Unocal 151 414 -33 .81 .12

Valvoline All Climate 135 405 -40 1.0 .11

Valvoline Turbo 158 405 -40 .99 .13

Valvoline Synthetic 160 435 -40 <1.5 .12

All of the oils above meet current SG/CD ratings and all vehicle manufacture's warranty requirements in the proper viscosity. All are "good enough", but those with the better numbers are icing on the cake.

The synthetics offer the only truly significant differences, due to their superior high temperature oxidation resistance, high film strength, very low tendency to form deposits, stable viscosity base, and low temperature flow characteristics. Synthetics are superior lubricants compared to traditional petroleum oils. You will have to decide if their high cost is justified in your application.

The extended oil drain intervals given by the vehicle manufacturers (typically 7500 miles) and synthetic oil companies (up to 25,000 miles) are for what is called normal service. Normal service is defined as the engine at normal operating temperature, at highway speeds, and in a dust free environment. Stop and go, city driving, trips of less than 10 miles, or extreme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. Synthetics can be run two to three times the mileage of petroleum oils with no problems. They do not react to combustion and combustion by-products to the extent that the dead dinosaur juice does. The longer drain intervals possible help take the bite out of the higher cost of the synthetics. If your car or bike is still under warranty you will have to stick to the recommended drain intervals. These are set for petroleum oils and the manufacturers make no official allowance for the use of synthetics.

Oil additives should not be used. The oil companies have gone to great lengths to develop an additive package that meets the vehicle's requirements. Some of these additives are synergistic, that is the effect of two additives together is greater than the effect of each acting separately. If you add anything to the oil you may upset this balance and prevent the oil from performing to specification.

The numbers above are not, by any means, all there is to determining what makes a top quality oil. The exact base stock used, the type, quality, and quantity of additives used are very important. The given data combined with the manufacturer's claims, your personal experience, and the reputation of the oil among others who use it should help you make an informed choice.

Note on Improving Performance

If you are "modding" your car and adding BHP or using it on track then consider your oil choice carefully as the stock manufacturers recommended oil will not give you the protection that your engine requires.

A standard oil will not be thermally stable enough to cope with higher temperatures without "shearing" meaning that the oil will not give the same protection after a couple of thousand miles as it it when it was new.

Let’s start with the fundamentals. An engine is a device for converting fuel into motive power. Car enthusiasts get so deep into the details they lose sight of this!

To get more power, an engine must be modified such that it converts more fuel per minute into power than it did in standard form. To produce 6.6 million foot-pounds per minute of power (ie 200 BHP) a modern engine will burn about 0.5 litres of fuel per minute.(Equivalent to 18mpg at 120mph). So, to increase this output to 300BHP or 9.9 million foot-pounds per minute it must be modified to burn (in theory) 0.75 litres. However, fuel efficiency often goes out of the window when power is the only consideration, so the true fuel burn will be rather more than 0.75 litres/min.

That’s the fundamental point, here’s the fundamental problem:

Less than 30% of the fuel (assuming it’s petrol) is converted to all those foot-pounds. The rest is thrown away as waste heat. True, most of it goes down the exhaust, but over 10% has to be eliminated from the engine internals, and the first line of defence is the oil.

More power means a bigger heat elimination problem. Every component runs hotter; For instance, piston crowns and rings will be running at 280-300C instead of a more normal 240-260C, so it is essential that the oil films on cylinder walls provide an efficient heat path to the block casting, and finally to the coolant.

Any breakdown or carbonisation of the oil will restrict the heat transfer area, leading to serious overheating.

A modern synthetic lubricant based on true temperature-resistant synthetics is essential for long-term reliability. At 250C+, a mineral or hydrocracked mineral oil, particularly a 5W/X or 10W/X grade, is surprisingly volatile, and an oil film around this temperature will be severely depleted by evaporation loss.

Back in the 1970s the solution was to use a thick oil, typically 20W/50; in the late 1980s even 10W/60 grades were used. But in modern very high RPM engines with efficient high-delivery oil pumps thick oils waste power, and impede heat transfer in some situations.

A light viscosity good synthetic formulated for severe competition use is the logical and intelligent choice for the 21st century.

Consider a "true" synthetic for "shear stability" and the right level of protection. Also, if going on the track, remember to use a oil separator and catch tank. Ideally get a bigger oil cooler and guages too.

Submitted by Monkeyra (derived from http://www.geocities.com/Yosemite/Gorge/6770/motor_oils.htm). Note on improving performance submitted by oilman, with the odd addition from percybigun.