Getahelmet.com Webmaster's note: Note this article was originally written in *1986* and yet much of the information it contains is still quite valuable. Use this info to educate yourself about the benefits of synthetic oil and help put to rest the myths about synthetic oil. Also keep in mind that synthetic oils have improved significantly since this writing.
Many people on the World Wide Web have illegally copied this article and butchered the original text. Many had good intentions, others didn't as they wanted to leave mention of certain brands (ie AMSOIL, Mobil 1, etc.) completely out of this wonderful article. Please use this article responsibly and DO NOT ILLEGALLY COPY IT!!! I (Aaron) specifically sought out the author (Curt Scott) and received his express permission. To our knowledge, this is the only 100% accurate digital copy in existence. I hand-typed this entire article from Mr. Scott's book and triple checked everything for typos/omissions. Mr. Scott is very accommodating to automotive enthusiasists, so just drop him an email. Although a nice guy, Mr. Scott will not screw around with pilferers. If you don't believe me, click on the Copyright Warning below and see for yourself how Curt deals with thieves.
Publishers Note: Since specialty car enthusiasts and street rodders often tend to be zealots when it comes to optimum care and maintenance of their cars, and also because so many of these cars utilize smaller, harder working engines, we at Homebuilt Publications felt that the following article would be of particular interest to Specialty Cars readers. Our own interest in the subject is personal as well as professional, since we have firsthand experience with the benefits of synthetic lubricants. One of our cars is a 1979 GM sedan whose odometer and maintenance records reveal over 200,000 miles of driving, with never a missed-beat of it’s 350 cu. in. gasoline engine, and which has never once required an engine repair… not even a minor one! It still runs as well as the day it was new, it’s sparkling clean inside, and all the cylinders check out to original compression specs. For all but the first 12,000 miles it has thrived on a strict diet of premium synthetic motor oil, changed once only every 25,000 miles. When we began research for this article, no one had to convince us that synthetics offer distinct advantages…
A sage observer is oft quoted, ”The only sure things in life are death and taxes.” However, it is a safe bet that an additional certainty should have been included: technological advancement.
Many of those things we take for granted as conventional aspects of twentieth-century life were unimaginable only a few decades ago. For instance, who would have foreseen in the 1940s, that in the 1980s, tiny electronic marvels called transistors would have effectively replaced the unreliable vacuum tube, or that a single, miniature silicon chip could duplicate the functions of an entire, room-sized digital computer, or even that hundreds of different exotic and classic automobiles would eventually be reborn and replicated in a new material called fiberglass, for assembly by the owner?
So it is with the rapidly emerging synthetic lubricant market. Those naysayers who only a decade or so ago prematurely dismissed synthetics as “snake oil” are now among the staunchest devotees of laboratory manufactured lubricants. Among these believers are top lubrication engineers, racecar drivers, vehicle fleet operators, and millions of private motorists around the world. What factors have contributed to the growing enthusiasm for synthetic lubricants? Simply put, synthetically produced lubricants have demonstrated beyond doubt that they are far superior to their conventional petroleum counterparts in fulfilling the many and varied tasks demanded of oil by today’s modern engines and power trains. Indeed, synthetic lubricant technology is swiftly progressing to a point where it is possible that engine wear may no longer continue to be the major limiting factor in the expected life span of motor vehicles. An examination of synthetic engine lubricants, along with a review of both laboratory and real world comparative test results, will assist the reader to understand the differences and the advantages offered by these state-of-the-art motor oils.
The first question demanding an answer is: Just what is synthetic oil? Technically speaking, synthetic lubricants are made by chemically combining, in a laboratory, lower-molecular-weight materials to produce a finished product with planned and predictable properties. Don’t be confused by this technical double-talk. What this means is that synthetics are custom-designed products in which each phase of their molecular construction is programmed to produce what may be called “the ideal lubricant.” This process departs significantly from that of petroleum lubricants, whose physical components, both desirable and undesirable, are inherited from the crude oil from which they are refined. Crude oil possesses thousands of varieties of contaminants, depending on the oil’s geographical and geological origins, which no amount of refining can entirely remove. Corrosive acids, paraffins and other waxes, heavy metals, asphalt, naphthenes and benzenes, as well as countless compounds of sulphur, chlorine, and nitrogen, remain in the finished product. Equally as important, petroleum oil molecules, as contrasted to uniform-sized synthetic oil molecules, vary significantly in size, shape, and length. When your engine heats up, the smaller molecules evaporate, while the larger ones tend to oxidize and become engine deposits. As a result, refined petroleum lubricating products differ widely in their overall quality and performance. The presence of and the resulting drawbacks of the undesirable constituent elements lie at the very root of the considerable performance differences between synthetic and petroleum-based motor oils.
As an adjunct to this narrative, it is important to point out those products that are sometimes confused as synthetics: currently-marketed graphite motor oil is a petroleum-based oil with a graphite compound added for additional lubricity (slipperiness), and is not synthetic. There are also numerous aftermarket oil additives on the market, offering claims of increased lubricity through the use of graphite, Teflon®, or metallic compounds. One is even supported by the bold declaration that it will "repair and seal" cylinder-wall wear and restore lost performance. Hmmm. Once again, while these products may or may not perform as claimed, they are not synthetics, and it may be safely stated that no additive or additive package is capable of conferring to petroleum oil the performance advantages of a premium synthetic oil. Consequently, as petroleum-based products, they will invariably break down as petroleum oils do under the conditions of stress and heat produced by an internal combustion engine. Public bewilderment and even skepticism have also occurred in years past, as unscrupulous, fly-by-night marketers advertised and promoted with exaggerated claims, oils and additives as "synthetic" which were of dubious quality, and in some instances were low-quality petroleum products merely labeled
"...cylinder wall and piston ring surfaces often exceed 500°F."
"synthetic." The names and addresses of the major, reputable manufacturers of synthetic automobile lubricants are listed at the end of this article for those who desire further technical information. Because Amsoil products are sold only through authorized distributors, the company suggests that you contact their headquarters for the name of a dealer near you, or consult your local telephone directory Yellow Pages under "Oils, lubricating." We should note also that many of the performance attributes of synthetic engine oils are also provided by a host of other synthetic lubricants, such as automatic transmission fluids, chassis and bearing greases, and gear lubes. Unfortunately it is beyond the scope of this article to detail the various benefits of these synthetic products.
Contrary to what many may believe, synthetic lubricants are not a recent development. As early as the 1930s, Standard Oil of Indiana conducted research into synthetic oil. More serious development and production was commenced by the Germans during WWII, as their conventional lubricants congealed and froze on the Eastern front and stalled their advances into the Soviet Union. As jet engines were developed after the war, it soon became evident that conventional lubricating oils couldn't withstand the high temperatures and pressures, and synthetics came to be used in all military and commercial jet aircraft engines. Then in the 1960s history repeated itself, and it was again cold weather that spurred further development work as the U.S. Army needed better lubricants for Arctic and Antarctic use. Still later, NASA specified synthetic-based lubes for all space vehicles, including the Space Shuttle. Today's automotive synthetic lubricants have evolved as an almost direct result of these demanding military and extraterrestrial lubrication requirements.
The U.S. Department of Energy lists no fewer than sixteen performance parameters for any modern automotive motor oil.
- Low temperature fluidity (low pour point)
- Low volatility…i.e. resistance to evaporation and resultant oil thickening…good oil economy, additional engine protection
- High temperature oxidation resistance (of the oil itself)
- Lubricity…the oil’s slipperiness
- Thermal stability…resistance to performance loss due to temperature change
- Compatibility with engine metals, elastomers (i.e. “rubber” seals), oil filter elements, paints and finishes
- Wear protection and film strength
- Freedom from deposit formation…good dispersant and detergent characteristics
- Compatibility with other engine oils and additive packages
- Extended drain capability
- Water stability…propensity to remain separate of water molecules
- Corollary effects on an engine’s octane requirements
- Ambient-startup protection…ability to protect against oil starvation during initial startup
- Anti-rust properties
- Compatibility with catalytic emission control systems
- Compatibility with alcohol-containing fuels
Chief among the areas in which the pre-planned and predictable properties inherent in premium synthetic lubricants significantly surpass those of petroleum oils are: low-temperature fluidity…and thus improved ambient startup protection; low volatility (higher boiling point…greater resistance to evaporation); high temperature thermal stability; oxidation resistance; lubricity; fuel economy; film strength and wear protection; extended drain capabilities; water stability; and high natural detergent characteristics (resulting in a cleaner engine with less additive content).
For purposes of comparison, we have taken a well-known synthetic engine oil, Amsoil 10W-40 synthetic, and contrasted its characteristics with those of several prominent 10W-40 conventional motor oils. Below is a condensed summary of the results of several closely monitored field and laboratory tests:
From this data it is readily apparent that synthetic lubricants have substantially broadened the horizons of engine lubricant protection. Simply by comparing the lubrication-temperature-range comparison, the limits of petroleum lubricants become evident. On both ends of the relevant temperature spectrum, synthetics demonstrate conclusively the ability to significantly extend the thermal regions in which the engine is protected. This has a special significance for those automotive power-plants which normally work harder and produce higher internal and lubricant temperatures…that is to say: high performance engines, smaller high-RPM engines, air-cooled engines, turbocharged engines, Diesels and rotaries. Furthermore, climatic conditions in which synthetics allow operation with full engine protection are for all practical purposes boundless, whereas with a petroleum oil the protective capacity significantly diminishes with temperature extremes. Note particularly the comparative viscosity (oil thickening) increases after the 64-hour Olds III-D test (item 2)…9% for the Amsoil synthetic vs. 102-400% for the multigrade petroleum oils; the reduced wear (item 3); and the reduction in crankcase temperatures (item 6). These favorable results are quite typical of virtually all similar test comparisons between petroleum and synthetic-based motor oils.
Low-temperature fluidity (“flowability”) becomes an important consideration where winters are severe. Because synthetics are constructed “building block by building block”, contaminants present in petroleum oil which contribute to low-temp thickening are entirely absent in synthetics, and fluidity is stable to as low as -65°F. Petroleum oils have an inherent percentage of paraffin crystals from their crude oil origins. As temperatures drop, these crystals enlarge and cause the oil to congeal. In extremely cold weather, petroleum oils become a solid mass, thus impeding cold starts, and when the engine does fire up, causing a period of engine operation without adequate lubrication until the lubricant is warmed enough to allow proper oil flow. Furthermore, because of synthetics’ better ring-sealing characteristics, fewer contaminants generated by fuel combustion are allowed to escape into the oil
"...oil-temperature decreases of from 20°F to 50°F are quite common with the use of synthetic oil."
pan. Thus the low-temp fluidity and film-strength properties of synthetics both contribute significantly to engine (and battery / starter / alternator) life in colder climates. In one cold cranking test conducted by Mobil, at -30°F, with Mobil 1 in the crankcase, the engine turned at an average speed of 152 RPM, and started; using 10W-30 and 10W-40 premium petroleum oils, the same engine cranked at 45 and 32 RPM respectively…and failed to start. Mobil states that is Mobil 1 (5W-30) all season synthetic may be used with complete confidence in any engine where 5W-30, 10W-30, 10W-40, or single viscosity oil is normally recommended by the manufacturer; its new “Formula 15W-50” synthetic is designed to replace and outperform those SAE 15W-40 and 20W-50 conventional oils preferred by some drivers for use in high-performance power-plants.
Ambient-start oil starvation is, at any temperature, a major cause of engine wear. Expert estimates vary as to how much abrasive wear is attributable to lubrication-starvation during initial startups, but it is generally conceded that a disproportionate share of an engine's abrasion and wear is caused during those few moments after initial cranking during which the oil has not yet reached full circulation. NEO Oil Company, a well-established and highly-respected producer of synthetic lubricants, has recently developed an extended-life lubricity additive for its synthetic motor oils specifically designed to remain on the bearing surfaces after engine shutdown and thus deliver additional lubrication and wear-protection for initial startups.
On the other end of the thermal spectrum, synthetic oils are also renowned for their high-temperature thermal stability. Superior high-temp stability ensures an engine lubricant’s capacity to protect vital engine components during very-high-temperature operation, such as hot summer driving, sustained high-speed driving, repetitious stop-and-go metropolitan driving, driving in mountainous terrain, pulling a trailer, or any driving with a small, harder-working piston or rotary engine. Underhood temperatures also take a quantum leap with the use of power options, especially air conditioning, and because of emissions devices and emissions-related engine redesign. It is important to note that, even though the dash gauge may register only a 200°F or so water/coolant temperature, the temperature of the sump and of all the assorted bearing surfaces significantly exceed the water temperature, and often surpass the 500°F on the piston ring and cylinder wall areas. These high-temperature surfaces serve to rapidly decompose petroleum oil and additives, as well as contribute to their shorter service life, while the synthetic is largely unaffected. Beyond the protection afforded and engine during these particular instances of high-operating temperatures, high-temp thermal stability moreover permits an engine oil to deliver overall extended service life (significantly longer drain intervals) in all driving conditions, because it prevents the phenomenon of sludge and carbon deposit formations on critical engine parts (valves, valve guides, oils channels, lifter assemblies, piston rings, et al.) due to oil thickening, a problem commonly attributable to petroleum oil breakdown at high temperature. As these deposits accumulate in the oil circulatory system, oil flow drops, thus accelerating engine wear. To the user of synthetics, the benefits are:
(1) Reduced wear of critical engine components;
(2) Significantly reduced sludge and varnish…a cleaner engine;
(3) Reduced engine drag due to uniform viscosity; and
(4) Increased fuel economy due to reduced component wear.
Mobil Oil recently reported the results of simulated hot-weather performance with its Mobil 1 synthetic as evaluated by a standardized, grueling engine test known as the Olds III-D. In this test, an Oldsmobile 350” V8 engine is run for 64 hours at a 100-hp load and 300°F crankcase oil temperature. This test is designed to measure an oil’s ability to resist oxidation and evaporation (and consequent thickening) at high temperature.(If it seems odd that oil would thicken at high temperature, consider the analogy of heating a pan of cold syrup on a stove. At first it would become quite thinner, but if left for, say, several hours, the resultant evaporation would cause the syrup to become progressively thicker). In order to qualify for the American Petroleum Institute’s top “SF” rating, a motor oil must pass the III-D test. This means it can thicken to no more than 375% of original viscosity at the end of 64 hours of continuous running. Mobil states: “To test the extra stability provided by the Mobil synthetic oil, we decided to run the III-D for 128 hours…double it’s normal length…and without oil drain. The Mobil 1 synthetic easily passed the test under these brutal conditions, thickening only an insignificant 20%. For comparison, a high-performance premium conventional oil was tested under identical conditions. That test had to stop at 96 hours; the oil had turned solid. Another premium conventional oil forced the test to stop at 112 hours, well before the end of the scheduled double length.” Amoco conducted an identical double-sequence III-D test on its Ultimate 5W-30 synthetic; it also passed the test with flying colors, thickening only 18%.
“Film strength” refers to the amount of pressure required to force out a film of oil from between two pieces of flat metal. The higher the film strength, the more protection is provided to such parts as piston rings, timing chain, cams, lifters, and rocker arms…wherever the lubricant is not under oil-system pressure. Synthetics routinely exhibit a nominal film strength of well over 3,000 psi, while petroleum oils average somewhat less than 500 psi. The result is more lubricant protection between moving parts with synthetics.
Viscosity is a crucial consideration when improvements in fuel economy are desired. It stands to reason that the freer an engine turns, the less fuel it will require to accomplish a given amount of work. Studies have demonstrated conclusively that engine drag is directly related to the viscosity of the motor oil. Generally speaking, the lower the viscosity, the better the fuel economy of the engine. In formulating lower-viscosity oils, it has become clear that synthetics are the base stock of choice. This is because it is possible to produce a synthetic oil of a given low viscosity without incurring the excessive oil consumption (due to evaporation) and resultant thickening of the same low-viscosity petroleum oil. Indeed, the U.S. Department of Energy, in its pamphlet entitled “An Assessment Of The Effects Of Engine Lube Oils On Fuel Economy”, states: “It is evident that low-viscosity oils will help minimize engine friction losses in the prevalent hydrodynamic region and thereby achieve better fuel economy. In addition, such oils help to reduce friction during ambient (cold) start by increasing the oil
"...oil flow furnishes up to 30% of an engine’s cooling requirements."
flow rate to critical engine parts. However, low-viscosity engine oils, blended from conventional petroleum base stocks, may have problems with high oil consumption and engine wear. There is also the possibility of decreased catalytic-converter life and efficiency due to the increased levels of phosphorous in the exhaust gas from the oil additives. One solution is to mix some synthetic oil with the mineral (petroleum) oil, or use a synthetic base stock entirely…”(end of quote). This low-viscosity, low-volatility character of synthetics has become increasingly important because many automobile manufacturers are now recommending lighter-weight (chiefly 5W-30) oils for use in their products, and because the trend toward smaller engines creates substantially more heat and stress on the oil used. In these smaller high-output powerplants, enough heat is generated to cause a lighter petroleum lubricant to evaporate and significantly increase viscosity within weeks of its introduction into the crankcase. High-temperature stability, as well as oxidation-resistance, is of absolutely paramount importance when it comes to turbocharged engines. Because it must both lubricate and cool the turbo unit, the oil MUST be specifically formulated to withstand the turbo’s extremely high operating temperatures. Oil film temperatures often exceed 450°F in the turbo unit during operation, and can surpass 650°F (!!!) during a short period immediately following engine shutdown…both figures far exceeding the thermal limits of petroleum oil. Synthetics, with their capacity to maintain proper (low) viscosity and lubricity under these high heat and stress conditions, and with their natural resistance to oxidation, have risen to the fore. It is also important to note that the high-temperature-stability properties of synthetics are designed primarily into the base-stock oil itself, rather than being achieved primarily with additives. The advantage with this approach is twofold:
(1) Additives, which may account for as much as 25% of the volume of a can of premium petroleum oil, by themselves have little or no lubricating properties per se. Thus the more the additive content in an oil, the less lubrication is available to the engine.
(2) Most additives tend to volatilize (evaporate) and deteriorate with heat and age and use, so that the overall effectiveness of the lubricant is significantly diminished within only a few thousand miles of driving.
It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30% of an engine’s cooling requirements. Prior to the introduction of synthetics, however, the problem of evaporation (and the resultant thickening of the remaining oil) was addressed primarily by increasing viscosity. In short, don’t be concerned with the relatively lower viscosity ratings of some synthetics. Syn lubes are a whole new ball game.
The remarkable ability of synthetic oils to reduce internal operating temperatures is far too important to ignore, since high operating temperatures contribute directly to premature failure of mechanical components and gaskets and seals. Coolant (i.e. water/antifreeze) cools only the upper regions of an engine. The task of cooling the crankshaft, main and connecting rod bearings, the timing gear and chain, the camshaft and its bearings and numerous other components must be borne entirely by the oil. There are three identifiable reasons why synthetics do a better job of cooling an engine: (1) Because of both the oil’s lubricity (slipperiness) and its stable viscosity, less friction—and thus less heat—is generated in the first place; (2) The molecular structure of the oil itself is designed to more efficiently transfer heat, even compared against the thermal conductivity properties (ability to absorb and dissipate heat) of an identical-viscosity petroleum oil; and (3) As mentioned in the preceding paragraph, the more rapid oil flow of these lower-viscosity synthetics contributes significantly to the efficient transfer and dissipation of heat. Because of all of these factors, oil-temperature decreases of from 20°F to 50°F are quite common with the use of synthetic oil. One might even say that the heat-reduction properties of synthetics are synergistic…by helping to reduce its own temperature, the synthetic oil is simultaneously enhancing the lubricant’s overall performance characteristics.
The advantage of extended drain intervals is one of the salient benefits of synthetic motor oils. In a landmark copyrighted article on synthetic motor oils which appeared in Popular Science magazine several years ago, the champion long-oil-drain performance of all was related by Ray Potter, Chief of Lubrication Research at Ford Motor Company for many years until his retirement several years ago. “Ten years ago”, Potter related, ”I was an unbeliever like Saul of Tarsus, who in his early years went about breathing fire, death, and indignation on the Christians, before Paul saw the light. So was I at the Scientific Laboratory of the Ford Research and Engineering Laboratory. Two companies asked if I was interested in synthetic oils, and I told them they were too expensive. But one of them sent some anyhow and we put it in the engine house and forgot about it.
Then one day one of the boys in the dynamometer room called and said they were short of oil and had an engine that would be dropped from scheduled testing unless we put something in it. I remembered the synthetic oil and gave him that. They ran it for 192 hours and called and told me I had better come over and take a look, so I looked and I had never seen anything so clean in my life. I said let’s put it (the oil) back in and run it another 192 hours. That’s where the petroleum oils sludge up badly. But when they had run it again, it was as good as when we looked at it before. So I said, ‘Let’s run it again’, and that was the first triple sequence I ever ran. We put the oil through 576 hours and that marvelous little Ford engine sat there running like a sewing machine and we pulled it down and it was fantastic.”
It is readily apparent that the performance and protection advantages exhibited by synthetic engine lubricants in laboratory tests suggest that their public acceptance will substantially increase in the future. But what about “the real world”? Does their performance parallel the test results and the claims of their manufacturers? The answer appears to be “Yes.”
In the same Popular Science article on synthetic oils, veteran racer car driver Smokey Yunick was quoted: “When you disassemble an engine that’s been run on petroleum oil, if you examine the rings and cylinder bores with a glass you’ll see ridges and scratches—that’s the wear going on. With polyol (a variety of synthetic), when you take the engine apart everything has the appearance of being chrome-plated. In the engine we ran at Indianapolis this year we used a polyol synthetic. When we tore the engine down, you could still see the original honing marks on the bearings…no wear at all. We put the same bearings back in because the crankshaft never touched the bearings. I’ve never seen that before.”
Another example of the capacity of synthetic oil to deliver exceptional engine protection and performance is a recently-completed demonstration involving the Amsoil Corporation of Superior, Wisconsin, a major manufacturer of a wide range of premium synthetic oils, automatic transmission fluids, chassis lubricants, and related products. This demonstration involved the use of its 100% synthetic engine oils in a New York City taxi fleet. The test, sponsored and supervised by a major lubricant additive manufacturer, compared the overall performance capabilities of Amsoil’s 10W-40 synthetic oil with a number of leading petroleum motor oils. The demonstration was scheduled to encompass 60,000 miles of New York taxi service on each car. With the high levels of idling time typically encountered in such service, the total number of “engine miles” of each car was estimated to be about double the miles registered on its odometer.
Initially the demonstration was to have required that each taxi, equipped with a Chevrolet 229 CID V6 engine, have its oil and filter changed every 3,000 miles. But Amsoil insisted that an alteration of the test procedure be instituted. The company’s intent was to push its synthetic oil to the extreme and evaluate how it compared to the petroleum oils drained at the originally specified, 3,000 mile intervals. The twelve Amsoil-lubricated vehicles were thus divided into three groups of four taxis each. Group 1 (Amsoil) would double the control interval, with oil and filter drain at 6,000 miles; Group 2 (Amsoil) would quadruple the control interval, with oil and filter drain at 12,000 miles; and Group 3 (Amsoil) would not change the oil for the duration of the test; thus multiplying the (petroleum) Control Group’s drain-control interval by twenty times. In place of changing the oil, these (Group 3) cars would be equipped with Amsoil’s By-Pass oil filter, claimed by the company to keep (synthetic) oil analytically clean for up to 25,000 miles of driving, without replacing the element. The by-pass filter element was changed at 12,500 mile intervals for the duration of the test.
Following the year-long demonstration, each of the engines was disassembled, both to determine the levels of sludge, varnish, and rust that had accumulated inside the engine, and to carefully measure the amounts of wear experienced on critical engine components. Pictured on the previous page are representative samples of various components of the test engines. In the first example, the pistons and intake valves of the petroleum Control Group (oil and filter changes every 3,000 miles) are illustrated. The lower set of photos represent the same engine components from an Amsoil Group 3 vehicle. Note the substantially reduced varnish and sludge deposits on the synthetic-oil lubricated components, and the remarkably good overall condition of the Amsoil Group 3 piston rings and valves.
To summarize the findings and conclusions, the test facility responsible for the demonstration submitted this statement: “The data presented in this report indicates that the Amsoil synthetic SAE 10W-40 passenger-car motor oil formulation…provided protection of the test engines from excessive wear and deposit formation, far beyond the normal 3,000-mile change interval.” In fact, the level of protection was such that those engines in which the original synthetic oil was run for the entire duration of the (60,000-mile) test showed less wear than did the Control Group vehicles using premium, 10W-40 petroleum oil and 3,000-mile drain intervals.
Many users of synthetics have reported that their fuel octane requirements have been lowered after switching to synthetics. One possible explanation for this phenomenon is that, because synthetic oils produce fewer combustion-chamber carbon deposits, due at least in part to its superior piston-ring-sealing properties, pre-ignition due to such deposits is correspondingly decreased. Also, at least in theory, spark plugs and valves should perform better and last longer for these same reasons.
Renowned race-car driver Bobby Unser stated in an article in The Family Handyman magazine: “I’ve had tremendous success with synthetics, both grease and oil, in all my cars. In several instances where we have compared petroleum-lubricated engines with those which used synthetics, the latter were cleaner, with less carbon and sludge. And the engines produced more horsepower, which meant better mileage and longer life.”
"...synthetics are way ahead of SAE standards."
Of particular relevance to VW-based kit car owners is a letter received by NEO oil company from a grateful customer in Paramount, California; excerpts as follows: “Thought we’d take a moment to write regarding the performance of your NEO synthetic motor oil…we decided to try your oil in our shop van, an early VW with a late model 1600cc, dual-port engine…Our findings, to say the least, are impressive! With absolutely no changes other than to drain out 2-1/2 quarts of a very good racing-grade 30-weight oil and then replace it with an equal amount of your 10W-40 synthetic, we noted an immediate 50°F drop (emphasis ours) in average cylinder head temperature (from 350° down to 300°), and a corresponding drop in oil temperature, from (former) highs of 270-290, now down to 230-240 degrees…Great news for VW owners, since high operating temperature is probably the number one cause of premature engine failures…Also significant, we have reduced our oil consumption from one pint every 300-350 miles, (depending on load conditions), down to NIL. In fact, as of this writing, we’ve put 6,363 miles on the van and we have added only three pints! As we stated earlier, we are quite favorably impressed with your product and are recommending it wholeheartedly."
Still another letter from a synthetic-oil user reads in part “…My GM owner’s manual recommends cleaning the PCV filter every 15,000 miles and replacing the (PCV) valve every 30,000. My odometer now
"These guys have apparently never heard about Mobil 1..."
registers well over 100,000 miles, and both components are still immaculate, like new, even though I’ve never had to clean the filter or replace the valve. Hell, except for a quick inspection prior to writing this letter, I’ve long since stopped checking them altogether. These guys have apparently never heard about Mobil 1…”
Finally, we asked a respected petroleum engineer why auto manufacturers don’t specify synthetic oils for use in their products. His response was both candid and revealing: “Auto manufacturers must, by necessity, stick to the ‘generic’ SAE standards in recommending oil grades and viscosities…and synthetics are way ahead of SAE standards. The top SAE motor oil classifications (SD, SE, SF, etc.), rather than being benchmarks of excellence, are merely ‘highest common denominators’. The highest SAE rating (currently ‘SN’ in 2010), for example, is determined not for the state-of-the-art performance of the better synthetics, but rather for the best possible performance of petroleum oils currently achievable by a majority of petroleum oil producers (emphasis ours). It is not surprising then that synthetics pass these qualifications effortlessly. What is needed is an entirely additional set of SAE standards, for synthetics. Such a grading system would, in effect, start where current SAE (petroleum-oriented) specs leave off. If such a premium grading system were adopted by the Society (SAE), then you’d see the automakers universally recommending lighter oils in grades and with recommended drain intervals completely beyond the reach of petroleum products…”
So given all of this information, what do we know about the performance characteristics of synthetic oils? We can say that they have significant performance and protective advantages over their petroleum counterparts, across an extremely wide range of operating temperatures. We have observed that synthetic oils, as a result of their stable viscosity and low volatility, are capable of providing superior protection to smaller, higher-RPM engines currently predominating the automotive market. We have seen that in “real-world” demonstrations, synthetic oils display extended drain capabilities far in excess of the recommended drain intervals of conventional petroleum motor oils. And finally, we have seen that synthetic lubricants demonstrate a remarkable ability to curtail sludge, varnish, and wear, in any engine.
“But”, you say, “if synthetics are so good, why aren’t even more motorists using them?” First and foremost, many folks simply aren’t aware of synthetics. Others who are aware are deterred by the higher purchase cost, without investigating the advantages. Even many professional mechanics haven’t kept abreast of the advances that have occurred in the field of synthetic lubricants, and frequently tend to dismiss them without bothering to check the wealth of current literature and impressive test results regarding them. Secondly, garages and dealerships often hesitate to recommend any extended-drain lubricant, perhaps because their livelihood is to a large degree dependent upon frequent servicing and repairs. We learned of one (probably common-occurring) instance where a dealership mechanic told a customer: “You can’t use synthetic oil in your car…the engine wasn’t designed for it!” Still another reason is that many of the advantages and cost-savings provided by synthetic lubricants are difficult to quantify, and thus difficult for many consumers to appreciate. For instance, how does one place a precise value upon such benefits as…”cleaner engine; longer engine life; fewer repairs; lower operating temperatures; fewer oil and filter changes; less oil consumption; lowered octane requirements; longer battery / starter / alternator / spark plug / turbo unit / PCV component life; increased fuel mileage; the convenience of exceptional four-season performance with a single motor oil…and so on.” On the other hand, it is quite simple to compare the purchase costs of conventional vs. synthetic, and to ignore the real cost-and-performance comparisons in actual operation. Do you prefer to save $12 or $15 per oil change by using a petroleum oil, even knowing that it should be changed six or seven times as frequently as a premium synthetic? Or are you more interested in the bigger picture, irrespective of the fact that many of the very real benefits of synthetics cannot be precisely quantified in terms of dollars and cents? All available evidence indicates that synthetic engine oils offer performance advantages not achievable with any refined-petroleum product.
Does all of this mean that synthetic motor oils are superior to conventional petroleum oils? If you value your automobile engine and would like to keep it in peak, trouble-free operating condition year after year and far beyond its normal expected life, our conclusion is “Yes, without question.”
We at Specialty Cars would like to extend special thanks to Peter L. Clark of Amsoil, Earl Kirmser of Earl Kirmser Inc./Mobil Oil, and Paul Baker of Neo Oil Company. Without their unselfish cooperation and technical assistance, production of this article would not have been possible.
Page created on 3/4/2003
Last updated on 3/10/2013