Opinion about Synthetic motor oil

Status
Not open for further replies.
Joined
May 19, 2003
Messages
10
Location
San Jose
Synthetic motor oil by Phil Bailey About ten years ago, when I was a local bright light in the Montreal radio world, I used to be approached to test a lot of automotive products. One such product was called 'Motrlube' and was being produced by a chemical company in Montreal. Initially, this company, in conjunction with the National Research Council, had been asked to develop a non freezing grease for the old fire hydrants in the city. Unfortunately, the synthetic grease they produced worked so well that the city's needs for the following years were far less than expected, so the company set out to find another outlet for its research and decided upon motor oil as a strong possibility. The secret was that this company had developed a catalyst that allowed them to blend together three different polyalphaolefins (PAOs) to produce a very superior product at low cost. As it happened, I was leaving for a 1300 Km run to Halifax the next week in my Golf, so I poured 4 litres of this dark brown brew into my engine, along with a new filter and off I went. Now, I had previously driven as far West as Calgary, for the usual reason. When working on a project, I would take my car to the site and fly home every weekend. Sometimes these projects would last for months, so I made some extra money and the client saved a bundle on rental car fees. As anyone knows, who drives long distances, one gets used to the rhythm and sound of the car. No need to watch the speedometer, you just know when you are traveling at a good cruising speed. I usually try to drive just 'under the radar' at about 117 Km/hour. Somewhere west of Quebec City, on the long run to Riviere du Loup, I happened to glance down at the speedometer and found myself running at 135 Km/hour. Foot off the loud pedal, settle down again, back up to 135K. The engine was running very smoothly indeed and I began to realize that this brown liquid in the engine was the reason for this quiet running. Usually, I achieved about 37 mpg on such a run. On this run I got over 41 mpg at a higher running speed. Since that day, I've used Motrlube, a company now based in Calgary, in all my cars. At that time, the Motrlube company claimed that the product was good for two years or 60,000 Km between oil changes. I decided to push the envelope and went for 3 years and 100K without an oil change. I changed the filter every year and at that time I sent a sample to a laboratory for analysis. The lab conclusion in every case was "do not change the oil'. Now this old faithful car of mine, is used for winter driving only. It has 400,000 Km on the clock and the body is held together with epoxy putty, but the engine starts first time in winter and has never been opened up for any reason except to change timing belts. It still burns no oil. I'm pretty sure that the use of pure PAO synthetics has produced this result. Equally, I use synthetics in the gearbox, which makes VWs notoriously reluctant gearbox work much better in very cold weather. Ten years later, everyone has a long life product, but there are still only a handful of pure PAO products on the market. Amsoil, Redline and Motrlube are three of the ones I know well and they are all very good products. (You can find the websites of all these companies through the Canadian Driver web index). Castrol, egged on by Audi, recently launched SLX Longlife II In Europe. And this oil has the ability to keep some engines operating for up to a staggering 30,000 miles (50,000 Km ) between changes. (Castrol's words, not mine). This Audi Variable Service concept (AVS) first appeared in the European A2 - a car designed without a hood for "minimal mechanical interference by the owner' - quote. The low maintenance idea has been extended to other cars in the Audi range since, and Longlife gives these cars the potential to cover up to 19,000 miles (30,000 Km ) between services. Audi's V6 TDI diesels can cover as many as 22,000 miles (36,000 Km ) before draining the sump and four-cylinder TDI diesels might, in the right circumstances, avoid mechanics for up to 30,000 miles. Audi spokesman David Goosey said "This oil has been developed to maintain its viscosity characteristics, and so deliver the key benefits of fuel efficiency and wear protection, throughout far longer oil drain intervals." Under AVS, Audi drivers no longer need to adhere to a traditional service plan. Instead, new Audis have an on-board system, which monitors both current engine condition, and the type of motoring the car has typically endured. It then tells the driver when a service is required via the instrument panel. Last time I was in the UK, I priced this product and it was selling for $20 a litre, which leads me to believe that this is definitely a pure PAO product. So what about the $7 products that we can buy over here? Products such as Castrol Syntec and Mobil1? Well, these products have a very good performance level, but cannot match the life of the pure PAO formulations. To start at the beginning, ordinary engine oil is a by-product of the refining process and becomes available whether the refiner wants it or not. As a lubricant, it has very little value at all until it is doctored with a group of additives, from which comes the viscosity and durability rating shown on the container. As we all are aware, the basic raw material is a very viscous black goo, that has to be diluted with solvents at the refinery so that it can be processed. Unfortunately, these solvents are carried over with the lubricating oil fraction and are the major reason for the rapid deterioration of the additives in less expensive oils. Within 2000 Km or so, low cost oil is not doing much of a job of lubricating your engine. At high temperatures, this oil carbonises rapidly and most of the black residue that drains out at an oil change is not engine wear, but burnt, deteriorated, oil that has carbonised itself into oblivion. A $1.50/litre motor oil, no matter what the brand name, should not be left in your engine for more than 5000 Km. 100% recycled oil, selling for eighty eight cents per litre in the big retail stores, has hit the market. Note that even these oils have an SF/CC rating, which only goes to show how low these standards really can be. So that, in general, ordinary engine oil has not improved much in the last five years or so. Now next up are the "100%' synthetics which carry a little disclaimer on their label: " not including carrier oil". These products are known as Hydrogenated Esters (HE) and are just properly modified and reprocessed mineral oils, although they certainly perform much more adequately and are probably good for 24,000 Km between drain periods, with regular filter changes. Fourth generation products, are now available, as used in the aircraft industry, where oil changes are uncommon, at least in jet planes. If one can find a way of formulating a PAO (polymer) based product containing no mineral oil whatsoever, at an affordable price, then one has a fourth generation engine lubricant that can remain in an engine, almost until the engine is rebuilt. Filtration of pure PAO lubricants is not challenging for the filter because no carbon is present, and the filter is doing what it should do, eliminating the odd metal particle. If you have a new car and wish to comply entirely with your warranty, then your owner's manual calls for an oil change every 12,000 Km. Changing a pure PAO product at this distance is major overkill, but costs only $65 on average and is therefore no more expensive than cheap oil changed every 4000 Km, particularly if the latter service is done at a dealership. Another common objection to leaving oil in an engine for long periods of time is contamination from products of combustion. In the case of mineral oil, one can actually form an emulsion with water, resulting in a beige coloured `mayonnaise' that is some times seen on oil filler caps. By contrast, PAO based lubricants shrug off water and acids and will not form emulsions. Consequently, as soon as the engine lubricant reaches the boiling point of the condensables, PAO's reject them through the PCV valve and go back to doing their job of lubricating the engine, completely unaffected by diluents of any kind.And now, let's put to bed all the objections you will hear concerning the use of synthetic engine lubricants: Myth #1: Synthetic motor oils damage seals. Untrue. It would be foolhardy for lubricant manufacturers to build a product that is incompatible with seals. The composition of seals presents problems that both petroleum oils and synthetics must overcome. Made from elastomers, seals are inherently difficult to standardize. Ultimately it is the additive mix in the oil that counts. Additives to control seal swell, shrinkage and hardening are required, whether it be a synthetic or petroleum product that is being produced. Myth #2: Synthetics are too thin to stay in the engine. Untrue. In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc) it has to meet certain guidelines with regard to viscosity ("thickness"). For example, it makes no difference whether it is 10W-40 petroleum or 10W-40 synthetic, at -25 degrees centigrade (-13F) and 100 degrees centigrade (212 degrees F) that oil has to maintain a standardized viscosity or it can't be rated a 10W-40. Myth #3: Synthetics cause cars to use more oil. Untrue. Synthetic motor oils are intended to use in mechanically sound engines, that is, engines that don't leak. In such engines oil consumption will actually be reduced. First, because of the lower volatility of synlubes. Second, because of the better sealing characteristics between piston rings and cylinder walls. And finally, because of the superior oxidation stability (i.e. resistance of synthetics against reacting with oxygen at high temperatures.) Myth #4: Synthetic lubricants are not compatible with petroleum. Untrue. The synthesized hydrocarbons, polyalphaolefins, diesters and other materials that form the base stocks of high quality name brand synthetics are fully compatible with petroleum oils. In the old days, some companies used untested ingredients that were not compatible, causing quality synthetic lubricants to suffer a bad reputation. Fortunately, those days are long gone. Compatibility is something to keep in mind, however, whether using petroleum oils or synthetics. It is usually best to use the same oil for topping off that you have been running in the engine. That is, it is preferable to not mix your oils, even if it is Valvoline or Quaker State you are using. The reason is this: the functions of additives blended for specific characteristics can be offset when oils with different additive packages are put together. For optimal performance, it is better to use the same oil throughout. Myth#5: Synthetic lubricants are not readily available. Untrue. This may have been the case two decades ago when AMSOIL and Mobil1 were the only real choices, but today nearly every major oil company has added a synthetic product to their lines. This in itself is a testament to the value synthetics offer. Myth #6: Synthetic lubricants produce sludge Untrue. In point of fact, synthetic motor oils are more sludge resistant than their petroleum counterparts, resisting the effects of high temperatures and oxidation. In the presence of high temperatures, two things happen. First, an oil's lighter ingredients boil off, making the oil thicker. Second, many of the complex chemicals found naturally in petroleum base stocks begin to react with each other, forming sludge, gums and varnishes. One result is a loss of fluidity at low temperatures, slowing the timely flow of oil to the engine for vital engine protection. Further negative effects of thickened oil include the restriction of oil flow to critical areas, greater wear and loss of fuel economy. Because of their higher flash points, and their ability to withstand evaporation loss and oxidation, synthetics are much more resistant to sludge development. Myth #7: Synthetics can't be used with catalytic converters or oxygen sensors. Untrue. In fact the very low ash content of synthetics will extend the life of every exhaust system component. Myth #8: Synthetics void warranties. Untrue. No major manufacturer of automobiles specifically bans the use of synthetic lubricants. In point of fact, increasing numbers of high performance cars are arriving on the showroom floors with synthetic motor oils as factory fill. Which may not make the dealers too happy since oil changes usually lead to other service work. Myth #9: Synthetics last forever. Untrue. Although some experts feel that synthetic base stocks themselves can be used forever, it is well known that eventually the additives will falter and cause the oil to require changing. However, by "topping off", additives can be replenished. Through good filtration and periodic oil analysis, synthetic motor oils protect an engine for lengths of time far beyond the capability of non synthetics. Myth #10: Synthetics are too expensive. Untrue. Tests and experience have proven that synthetics can greatly extend drain intervals, provide better fuel economy, reduce engine wear and enable vehicles to operate with greater reliability. All these elements combine to make synthetic engine lubricants more economical that conventional non synthetics. In Europe, synthetics have enjoyed increasing acceptance as car buyers look first to performance and long term value rather than initial price. As more sophisticated technology places greater demands on today's motor oils, we will no doubt see an increasing re-evaluation of oil buying habits in this country as well. Conclusions Since their inception, manufacturers of synthetic motor oils have sought to educate the public about the facts regarding synthetics, and the need for consumers to make their lubrication purchasing decisions based on quality rather than price. As was the case with microwave ovens or electric lights, a highly technological improvement must often overcome a fair amount of public skepticism and consumer inertia before it is embraced by the general population. But the word is getting out as a growing number of motorists worldwide experience the benefits of synthetic lubrication. The wave of the future, in auto lubes, is well under way. For the environmental enrthusiasts, the use of synthetics could reduce waste oil disposal by 80%, so if environment is your thing, then synthetic lubricants should be your choice. As a footnote, we have tried to sell expensive synthetics on the environmental argument, with no great success. Unless you can also show an economic advantage, the general public will not invest.
 

Jewel

Thread starter
Joined
May 19, 2003
Messages
10
Location
San Jose
Synthetic Engine Oil by Jim Kerr Synthetic engine oils have been around for decades and work very well. Just like many other products, they are always being improved and boldly marketed. Motorists may not be sure if the manufacturer's advertised claims about the synthetic oils are correct, or if they are just hype to entice buyers to the more expensive lubricant. Recently Pennzoil came out with a new synthetic oil with their new special additive "Pennzane". I thought I would try the Pennzoil Synthetic oil in one of my own vehicles to see how it performed. Let me start by saying I wasn't expecting miracles. Even though the "Pennzane" oil additive is a synthesized hydrocarbon fluid and has been used by NASA since 1989 as a lubricant for space-going mechanisms, I didn't expect to launch my pickup truck into orbit. I also didn't expect the synthetic oil to be a "Mechanic in a Can" and repair or eliminate any mechanical problems with my truck's engine (it has none I am aware of). What I was expecting was better engine protection during extreme temperatures, both hot and cold, and maybe a slight change in engine performance. I was also interested to see if the synthetic oil would make any difference in exhaust emission levels. An exhaust gas analysis of the truck shows the hydrocarbons levels slightly high, but the truck performing well otherwise. Operating the truck on the dynamometer enabled a baseline horsepower and emissions test to be done while driving at 100 kph. After running some preliminary tests, the old oil was drained and the engine filled with the new Pennzoil 10W-30 Synthetic engine oil with "Pennzane" additive. I started my investigation by running a baseline test on my truck. It is a full size GMC two-wheel drive pickup truck equipped with a 5.7 litre V8 engine and automatic transmission. The truck has had routine maintenance since new and with 30,000 kilometres on the vehicle, the engine has had a chance to break in completely. I hooked the truck up to our chassis dynamometer and drove it until the engine, transmission, and axle were completely warmed up. I was then ready to do some measurements. The truck was due for an oil change, but I wanted to take an emissions sample and horsepower measurement before switching to the Pennzoil synthetic. I used a Snap-On four gas analyzer to check the exhaust emissions while driving the truck at 100 kph on the dyno. The readouts for carbon monoxide, carbon dioxide, and oxygen were fine, but the hydrocarbons level was a little higher than I expected for a vehicle equipped with a catalytic converter. Perhaps the converter had degraded in performance because of using gasoline with a high sulphur content, or the engine could be running a little rich because of oxygen sensor contamination, but I was just interested in a base line measurement. I would have to check out the hydrocarbons level later. Next, I took a horsepower readout from the dyno. Rear wheel horsepower is always much lower than advertised horsepower rating but I wasn't after maximum horsepower; I wanted to see if there were any gains at part throttle driving. I set the dynamometer so it would load the vehicle with an eight horsepower load at 100 kph. This is how much horsepower it takes to drive a typical full size pickup down the highway at that speed. Then I measured the throttle opening by reading the data from the truck's engine computer. It all sounds high tech, but it is really very simple to do if one has the equipment, and I felt it was necessary to take these measurements to make my evaluation as objective as possible. Finally, it was time to change the oil. I installed a new original equipment oil filter (same as before) and five litres of Pennzoil Synthetic Oil with Pennzane. After running the engine for 15 minutes to ensure the oil was on all moving parts inside the engine, I stabilized the engine temperature and ran the truck at 100 kph on the dyno to check the throttle data. It showed no significant difference, which would indicate that there was no horsepower increase at highway cruising speeds. It is important to remember that horsepower readings are affected greatly by engine temperature, underhood air temperature, and humidity. I tried to make the two horsepower tests as similar as possible but there is room for error. What I can say from my experience, is that synthetic oil will not give you a BIG horsepower increase. Next, I retested the exhaust emissions levels. Again, I found no real differences. There seemed to be no reduction of emissions by switching to synthetic oil in a good running engine. The tests confirmed what I suspected; I would have to test the oil over the long term to see if I could find any benefits. The next test came a week later. I took the family on holidays through Montana. It was hot! The temperature exceeded 40 C and the speed limits are high. The truck performed flawlessly, and did not use any oil in 2000 kilometres of driving. I also notice the oil pressure gauge remained in the normal range with the engine idling, instead of dropping to the low end of the scale as it has done during previous hot weather driving. This test was definitely subjective, but it reinforced my belief in one of the advantages of synthetic oil; Synthetic oils don't change viscosity as much when they get hot and therefore they can protect the engine better. Several cars require synthetic engine oil to meet the manufacturer's warranty requirements. Typically, these are high performance vehicles that generate a lot of heat in the engine during spirited driving. Synthetic oils provide the extra protection during hot engine conditions. It was only a few weeks later that I was able to check the oil performance during cold weather. While we have not reached the frigid temperatures of winter, the temperature has already dropped to -14 C where I was driving. I noticed the engine cranked quickly, and the oil pressure rose immediately upon starting the truck. This seemed to be a faster rise in oil pressure during cold temperatures than I previously had with regular oil. The synthetic oil did not seem to thicken as much during cold temperatures and therefore could provide better lubrication during cold weather starting. While I realize this is very subjective evaluation, I did place one sample of synthetic oil and a similar one of regular oil in the freezer and found the synthetic oil did pour easier after being frozen for a few hours. Finally, after five thousand kilometres of driving, I completed my evaluation by re-testing the horsepower output and exhaust emissions levels. There were no significant changes from my initial tests. So what are the advantages of synthetic oil? It would appear the manufacturer's claims of better engine protection at extreme driving temperatures are the key advantages. If you work your engine hard, drive in extreme heat, or have cold weather starts, then synthetic oil should protect the engine better. The disadvantages of synthetic oil are mainly the cost of the oil. It is more than twice as expensive as regular oil and still needs changing at the same mileage intervals as regular oil. Synthetic oils may not break down as regular oils do over time, but one of the main reasons for changing oil is to remove crankcase acids and contaminants caused by the combustion process. Synthetic oil gets "dirty" just as regular oil does. Synthetic oils cost more, but the cost is insignificant compared to the cost of engine mechanical repairs. If your climatic conditions or driving style warrant the use of synthetic oil, then it is worth the few extra dollars. As for my truck, I plan to operate the truck with synthetic oil over the winter to gain personal experience in starting performance at -40C temperatures! Real life testing can sometimes be tough on the tester and the vehicle!
 
Joined
Nov 15, 2002
Messages
8,937
Location
SC
quote:
Originally posted by Jewel: Synthetic motor oil by Phil Bailey
Phil is full of crapola. When I find fundamental inaccuracies in someone's writing on a subject, I tend to discount everything else that person has to say. This guy has plenty of fundamental inaccuracies as well as half-truths. There is more hard data and informed opinions about synthetics to be found by digging around on this forum than is in this "report" by Phil Bailey.
 
Joined
Jan 16, 2003
Messages
4,478
Location
Southern California
Let's see, Phil Baily waxes eloquently over "pure PAOs" as the nirvana of motor oil technology. And Jim Kerr similarly gushes over Pennsy's synthetic with the marvelous "Pennzane" additive. Is Kerr aware that Pennsy's "full synthetic" is Group-III based? And, what about this "Pennzane" stuff? "Additive"? I was under the impression from the ad copy on the bottles that "Pennzane" was Pennsy's nomenclature for for their synthetic base oil. Is this wrong? Is "Pennzane" perhaps an ester or other Group-V? In any event I find the two "reports" at odds. Both essays extoll the virtues of synthetics, but neither agrees on what constitutes a "synthetic" motor oil. (with one author possibly unaware of the "raging" debate on whether a Group-III should legitimately be defined as a synthetic fluid...). One essay intimates that you can just about run an engine forever on a particular regionally available synthetic oil. The other says change the synthetic out at the engine manufacturer's specified intervals. Except for irreconcilable chemical and maintenance schedule exceptions, these two reports are in 100% agreement on all points! [Big Grin] Jewel, is there any indication when these essays were written? [ June 10, 2003, 10:56 AM: Message edited by: Ray H ]
 

Patman

Staff member
Joined
May 27, 2002
Messages
22,033
Location
Guelph, Ontario
Pennzane is an extremely expensive additive, so expensive in fact that many people believe there are only a few drops of it in each bottle of Pennzoil synthetic.
 

Jewel

Thread starter
Joined
May 19, 2003
Messages
10
Location
San Jose
by Phil Bailey Ordinary engine oil is a by-product of the refining process and becomes available whether the refiner wants it or not. As a lubricant, it has very little value at all until it is doctored with a group of additives, from which comes the viscosity and durability rating shown on the container. As we all are aware, the basic raw material is a very viscous black goo, that has to be diluted with solvents at the refinery so that it can be processed. Unfortunately, these solvents are carried over with the lubricating oil fraction and are the major reason for the rapid deterioration of the additives in cheap oil. Within 1000 Km, your ordinary oil is not doing much of a job of lubricating your engine. At high temperatures, this oil carbonises rapidly and most of the black residue that drains out at an oil change is not engine wear, but burnt, deteriorated, oil that has carbonised itself into oblivion. A $1.50/litre motor oil, no matter what the brand name, should not be left in your engine for more than 5000 Km. 100% recycled oil, selling for eighty eight cents per litre in the big retail stores, has hit the market. Note that even these oils have an SF/CC rating, which only goes to show how low these standards really are! So that, in general, engine oil has not improved much in the last five years and may, in fact, be less durable than it used to be. Here come the so-called 100% synthetics which carry a little disclaimer on their label: " not including carrier oil". These products are known as Hydrogenated Esters (HE) and are little more than properly modified mineral oils, although they certainly perform much more adequately and are probably good for 24,000 Km between drain periods, with regular filter changes. Fourth generation products, are now available, as used in the aircraft industry, where oil changes are uncommon, at least in jet planes. If one can find a way of formulating a PAO (polymer) based product containing no mineral oil whatsoever, at an affordable price, then one has a fourth generation engine lubricant that can remain in an engine, until the engine is rebuilt. Filtration of pure PAO lubricants is not challenging for the filter because no carbon is present, and the filter is doing what it should do, eliminating the odd metal particle. If you have a new car and wish to comply entirely with your warranty, then your owner's manual calls for an oil change every 12,000 Km. Changing a pure PAO product at this distance is major overkill, but costs only $85 on average and is therefore no more expensive than cheap oil changed every 4000 Km, particularly if the latter service is done at the dealership. Another common objection to leaving oil in an engine for long periods of time is contamination from products of combustion. In the case of mineral oil, one can actually form an emulsion with water, resulting in a beige coloured `mayonnaise' that is some times seen on oil filler caps. By contrast, PAO based lubricants shrug off water and acids and will not form emulsions. Consequently, as soon as the engine lubricant reaches the boiling point of the condensables, PAO's reject them through the PCV valve and go back to doing their job of lubricating the engine, completely unaffected by diluents of any kind. If we still have your attention, here's a more technical expalnation: Since different fractions of the crude have different boiling points as well as different viscosities, progressive boiling is used. Those fractions with lower boiling points are allowed to vaporize, and are collected and then cooled. These neutral fractions typically have lower viscosities, while the bright stocks (those with higher boiling points) generally have higher viscosities. As such, we can separate oils by viscosity. But here's a problem. If we compound an oil to have a relatively low viscosity (or a multi-vis oil with a significant amount of these lower boiling point/lower viscosity stocks) some of them will vaporize at high temperatures, resulting in higher oil consumption. What's left behind has a higher viscosity. Varnish and sludge are also present. If the decrease in viscosity, amount of sludge, varnish, and cam lobe wear are too high, it fails the API service test. That's why a 5W-30 oil that meets the SF rating represents a major step. Those oils are said to be "energy saving" since their lower viscosity at lower temperatures (with thick-film lubrication. Remember, if the viscosity is too low, surface-to-surface contact may occur resulting in increased friction and wear!) results in lower part-to-part friction. Yet by passing the SF rating, it shows that it's still pretty good. Now, there are many things in the average motor oil than various refined fractions of crude. Included are various additives, such as anti-wear agents, extreme pressure (EP) additives, anti-rust agents, . Most of these are self-explanitory. They are added to enhance the performance of an oil. The EP additives are put in to help the oil hold up between surfaces which feature high contact stresses such as those between the cam lobes and followers. Detergents and dispersants are put in to help remove dirt and sludge and hold it in suspension, until it's either removed in the filter, or the oil is changed. Also included are various oil modifiers such as pour point depressants, viscosity index (VI) improvers, and seal swell agents. Pour point depressants are added to inhibit wax crystal growth at low temperatures. This gives the oil better cold cranking performance. VI improvers are designed to help an oil's viscosity/temperature performance. Remember that at high temperatures, an oil's viscosity drops. If it drops too low, we lose film thickness, and are in big trouble! The viscosity index (VI) is a measurement of how an oil's viscosity changes with temperature, compared to reference oils. The higher the number, the better. VI improvers are polymer compounds with interlocking structures (polymers are long chain molecules). Because these chains are interlocked, they don't move as easily at high temperatures and resist viscosity loss. Unfortunately, they don't necessarily contribute anything to lubricity, and in fact begin to wear out under shear stresses. As they wear, the oil's VI deteriorates, and we're left with the old VI improver, which has to be held in suspension. This is another reason to change your oil frequently! The VI improver's sensitivity to high shear stress is significant in that if the shear stress is high enough, the oil may experience either a temporary or permanent loss of viscosity! Finally, an oil company may add various compounds which help protect the base stock, such as anti-foam agents, antioxidants, and metal deactivators. The antioxidants are important as they prevent the oil from reacting with oxygen at high temperatures and forming sludge, varnish, and lacquer. So where do synthetics fit in? What are they? The term "synthesize" means to put together from small bits. Rather than separating crude into various fractions as is done with conventional oils, synthetic base stocks are made by reacting various organic chemicals together. For instance, if an acid an an alcohol are allowed to react, a compound known as an ester is produced. (As an aside, the aroma present in flowers is generally produced by an ester. Others include butter, lard, tallow, linseed, cottonseed, and olive oils - although I wouldn't substitute my favorite engine oil for any of them in my cooking, or viceversa!) Other synthetic hydrocarbon compounds are also suitable for lubricating oils, and manufacturers may blend two or more compounds together to arrive at suitable properties. It should be noted that many additives are also made of synthesized compounds. First, though, let's compare a conventional oil to a synthetic. A synthetic may require considerably less VI improver to have the same viscosity index. Remember that the VI improver wears out. Synthetic's are also more thermally stable. Synthetic base stocks also have lower pour points - often below -50 degrees F, and require little or no pour point depressant. In contrast, bright stocks may stop pouring at 25-30 degrees F, and need it. Still, synthetics are a bit more expensive, so compounding one to compete directly with a conventional oil may not make economic sense. That's why they are usually made to have superior properties. The extra performance is often worth the cost penalty. For instance, synthetics can be compounded with very low pour points. This gives good cold-cranking performance. They may also be compounded with slightly lower viscosities at lower temperatures (while still meeting SAE specifications). This helps to reduce friction, and results in less wear, and better fuel economy. Now the 5W-30 "energy saving" oils will do the same thing, but as we've discussed before, to lower the viscosity, these oils may be compounded with fractions which have a higher volatility. After a period of time, they begin to boil off or oxidize, leaving behind an oil of higher viscosity. Now, that same oil may meet API SF specifications, but a synthetic may remain stable for a LONGER period of time. (Esters exhibit excellent performance in the API test. Other compounds are very, very good also.) That means that longer drain intervals are possible. A word on use. Some synthetic compounds are not compatible with conventional oils. However, most manufacturers, have recognized that one may add a quart of their product to someone else's, and have compounded them to be. To do otherwise would be to pass up their intended market! (As an aside, I try to avoid having to mix conventional oil, if I can help it. While they are also compounded to be compatible, the performance may not be the same when mixed together. It's ok in a pinch, but I don't make a habit of it.) Also, the lower friction resulting from the use of a synthetic lubricant makes them unsuitable for break-in. To sum up, synthetics provide an excellent alternative to conventional oils - especially if better performance is required. It's your choice! --------------------------------------------------------------------------------
 

Patman

Staff member
Joined
May 27, 2002
Messages
22,033
Location
Guelph, Ontario
quote:
That's why a 5W-30 oil that meets the SF rating represents a major step. Those oils are said to be "energy saving" since their lower viscosity at lower temperatures (with thick-film lubrication. Remember, if the viscosity is too low, surface-to-surface contact may occur resulting in increased friction and wear!) results in lower part-to-part friction. Yet by passing the SF rating, it shows that it's still pretty good.
Based on this one paragraph alone, we can see how severely outdated this article is. SF oils were over 15 years ago, if not more. IIRC, I was using SF oil in my brand new 1988 Dodge Shadow Turbo!
 
Joined
Sep 18, 2002
Messages
5,482
Location
VA
quote:
Originally posted by G-Man II: When I find fundamental inaccuracies in someone's writing on a subject, I tend to discount everything else that person has to say. This guy has PLENTY of fundamental inaccuracies as well as half-truths. [/QB]
HE sure had PLENTY of WORDS. [Big Grin] G-Man II, I'm gonna take your word for it. MY attention span couldn't hold out... [freaknout]
 
Joined
Jun 21, 2002
Messages
2,759
Location
CarMax
quote:
Originally posted by Eiron:
quote:
Originally posted by Patman: SF oils were over 15 years ago, if not more. IIRC, I was using SF oil in my brand new 1988 Dodge Shadow Turbo!
Hey! I noticed, just two days ago, that WalMart carries both an SF-rated oil (Accel 10W-40) & an SA-rated oil (Accel 30; non-detergent, I think). Both a bargain at only $0.79/qt! -Greg

Funny you mention that. I was just at Quik Trip (gas station/mini market) and looked at their oil lineup ( ya know I had to...). They had a 30W oil that was SA-rated. Price? $1.49 per quart. My neighborhood supermarket also stocks a SA-rated 30W. Their price is also $1.49. Guess we know where all the overpriced cheap oil is being sold. Right here in the Peach State.
 
Joined
Sep 25, 2002
Messages
951
Location
Loveland, Colorado
quote:
Originally posted by Patman: SF oils were over 15 years ago, if not more. IIRC, I was using SF oil in my brand new 1988 Dodge Shadow Turbo!
Hey! I noticed, just two days ago, that WalMart carries both an SF-rated oil (Accel 10W-40) & an SA-rated oil (Accel 30; non-detergent, I think). Both a bargain at only $0.79/qt! -Greg
 

Patman

Staff member
Joined
May 27, 2002
Messages
22,033
Location
Guelph, Ontario
Now I remember Greg, I believe it was SG oil I was using in my Shadow, but the filler cap may have said that SF was ok to use. SG probably must've come out right around that time I bet (87-88)
 
Joined
Sep 25, 2002
Messages
951
Location
Loveland, Colorado
quote:
Originally posted by bretfraz: Funny you mention that. I was just at Quik Trip (gas station/mini market) and looked at their oil lineup ( ya know I had to...). They had a 30W oil that was SA-rated. Price? $1.49 per quart. My neighborhood supermarket also stocks a SA-rated 30W. Their price is also $1.49. Guess we know where all the overpriced cheap oil is being sold. Right here in the Peach State.
Well, maybe not all of it! Did you see this follow-up on Star Brite in "Lube Report"? And I'm in Colorado, so we're getting our share out here, too. The article describes SA-rated oils as "not suitable for use in most gasoline-powered automotive engines built after 1930," & API's description of this obsolete rating is "For older engines; no performance requirement. Use only when specifically recommended by the manufacturer." (I especially like the "no performance requirement" part! [Eek!] ) Patman, According to the API's chart, SF was introduced in '79! You're right, this cut-&-paste is extremely outdated material. -Greg
 
Joined
Jun 16, 2003
Messages
16
Location
Oklahoma
Wow! That thread took me over an hour to read; stepping away from my desk at times of course. Interesting stuff in 1980 and still is today; it had my attention and I kept wondering if the "SF" rated oils was just a typo or when that was written. Those articles were written about 5 yrs. prior to my entrance into the synthetic lube industry; very good reading even if just to help touch up on our history skills. It's amazing how folks used to be so skeptical of synthetics and today they've become widely accepted as the lubricant of choice. Thanks for sharing Jewel.
 
Status
Not open for further replies.
Top