Synthetic Oil Myths      During the early development and formulation period of synthetic motor oils, certain additives and techniques were used which made synthetics incompatible with some seals found in motor vehicle engines. There was also a question of whether or not synthetics could be reliably mixed with conventional oils. Because of these facts, synthetics received a bad reputation, which has caused modern synthetic manufacturers to have to re-educate people about their products. There are also many other myths floating around about synthetic lubricants and some clarification is needed. The following was written by Ed Newman and published in National Oil & Lube News. Mr. Newman effectively sets the record straight on many common synthetic misconceptions. 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. 2. Synthetics are too thin to stay inside 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 (212F), that oil has to maintain a standardized viscosity or it can't be rated as 10W-40. 3. Synthetics cause cars to use more oil- Untrue. Synthetic motor oils are intended to be used 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). 4. Synthetic lubricants are not compatible with petroleum products- 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 synlubes to suffer a bum rap. 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 fact 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. 5. Synthetic lubricants are not readily available- Untrue. This may have been the case two decades ago when Amsoil and Mobil 1 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. But, beware, many of the other "synthetics" are not true PAO (Polyalphaolefin) synthetics (i.e. Castrol Syntec, Pennzoil etc.). They are hydroisomerized petroleum oil or an ester based synthetic blend. 6. Synthetic lubricants produce sludge- Untrue. In point of fact, synthetic motor oils are more sludge resistant that 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 basestocks begin to react with each other, forming sludges, 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 flashpoints, and their ability to withstand evaporation loss and oxidation, synthetics are much more resistant to sludge development. Two other causes of sludge-ingested dirt and water dilution- can be a problem in any kind of oil, whether petroleum or synthetic. These are problems with the air filtration system and cooing system respectively, not the oil. 7. Synthetics can't be used with catalytic converters or oxygen sensors- Untrue. There is no difference between synthetic and petroleum oils in regards to these components. Both synthetic and petroleum oils are compounds and neither is damaging to catalytic converters or oxygen sensors. 8. Synthetics void warranties- Untrue. No major manufacturer or 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. New vehicle warranties are based upon the use of oils meeting specific API Service Classifications (for example SG/CE). Synthetic lubricants, which meet current API Service requirements, are perfectly suited for use in any vehicle without affecting the validity of the new car warranty. In point of fact, in the over 25 years that Amsoil Synthetic Lubricants have been used in extended service situations, over billions of miles of actual driving, these oils have not been faulted once for voiding an automaker's warranty. 9. Synthetics last forever- Untrue. Although some experts feel that synthetic basestocks themselves can be used forever, it is well known that eventually the additives will falter and cause the oil to require changing. Moisture, fuel dilution and acids (the by products of combustion) tend to use up additives in an oil, allowing degradation to occur. 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. 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 oils more economical than 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. Arguments Against Synthetics      The most common argument that I hear about synthetics sounds something like this: "I have been using petroleum oils for years, changing my oil religiously at 3K miles and I have never had an engine related problem." While this may be true, why go through the hassle of changing the oil unnecessarily every 4 months or 3K miles? In a world where there are so many things competing for our time, many people welcome the chance to allow their oil to remain in the crankcase for 1 year without having to give it a second thought. Not only do they have the assurance that it is doing a much better job than petroleum oil, they don't have to worry about changing it out as often.      Another common argument I hear sounds something like this: I change my oil religiously at 3K miles and use only petroleum oil, but when I took the heads off, I could still see original hone marks in the cylinder walls. For every comment like this that I have heard, I have come across many situations where people are doing costly engine overhauls or component replacement due to worn out parts regardless of their maintenance schedule. Recently I talked to a gentleman who had his truck at a dealership to do a recall on the cylinder heads and was informed that there were nasty ridges at the tops of his cylinders and it would cost him close to 3K to overhaul the bottom end of the engine. This engine was meticulously maintained with petroleum oil and had well under 100K miles on it. Did the oil cause this? That is hard to say. Was the owner of this 1995 pickup bummed to have to be thinking about an engine overhaul? Yep!!      Any time an owner is planning to keep a vehicle for many years, I always recommend a synthetic oil. While a petroleum based oil may be adequate, I demand the best for my vehicles. I plan to keep my vehicles for many years and hundreds of thousands of miles and that is why I use synthetic lubricants. Could I go 200K on a vehicle using petroleum oil? I am sure I could but I am also sure that I could go 400K on the same engine using synthetic oils. Conclusion      Whether or not you decide to switch over to synthetics will depend on whether or not you see or can feel a difference in the way your vehicle runs to justify the cost of synthetic oils or if you feel that the other characteristics of synthetics are worth spending the extra money. I am a firm believer in the benefits of synthetics and I would much rather pay a little extra for a lubricant that I can put in and not have to worry about changing for an extended period of time. I also have the knowledge that the synthetic is doing a better job at lubricating than any other lubricant which means I won't have to worry about costly overhauls as often as I would with other lubricants. Synthetic lubricants are easily accessible at auto parts stores or online parts houses. Independent product testing proves synthetics to be, in every way, superior to any kind of petroleum lubricant. The only thing that you need to decide is if it is worth the money to you to protect your costly investments. *I have no affiliation with Amsoil, Inc. I use their products along with other top quality synthetic products. The information found in this article was current as of 11/02 but because of the changing nature of automotive products, it may not be as current at the time you read it. There is ample information on the world wide web about synthetic lubricants and I encourage you to do some of your own research before making a decision on which oil to use in your vehicle. If you want to contact me directly, I welcome any correspondence via email at toddhen1@juno.com Go back to page 1 by Todd Henderson Do you have thoughts, opinions or questions about this article? Join the discussion here.