<p>Dear CCer’s</p>
<p>synthetic motor oil has been around so long now, is it really worth it to use that instead of conventional motor oil ? I am looking for practical examples not manufacturer claims.</p>
<p>Thank you in advance. CD</p>
<p>All of my cars have gone well over 200,000 miles using conventional bulk motor oil. In most cases, I think you get a much greater benefit from changing the oil and filter on a regular basis (I do it every 5,000 miles, even though my current car’s service interval is 10,000) than you do from using a synthetic oil. It may be that in certain conditions (extreme cold, desert heat, towing, etc.) that a synthetic oil provides maximum protection for the engine and is more resistant to breaking down quickly than is conventional motor oil. But most of us don’t drive under those conditions on a regular basis.</p>
<p>On my older cars, the oil change interval was 3,000 miles and my service places used conventional oil. On my current car (2000 and 155K miles and runs like new), they use synthetic and the service interval is 5000 miles.</p>
<p>I’m pretty sure that I had some odd engine repairs on my older cars but my guess is that it was the difference in manufacturer quality than the oil type. I just use whatever the manufacturer suggests.</p>
<p>I normally do oil/filter changes at 3-4K miles. I just bought another case of oil and was stupified at the cost/qt. I’ve gone as long as 10K between changes and have use synthetics when there was a much higher cost differential without noticing any affects. </p>
<p>Since I already have enough oil for 2 changes, I may increase the interval between changes to 4-6K miles and take my chances. If I were using synthetics I’d probably change at 10-14K, if you plan to keep your car much longer.</p>
<p>I always change the oil myself, use conventonal oils, and change the oil and filter every 3000-4000 miles. My Dodge Durango now has 153,000 miles on it and the engine’s doing fine. I keep all of my cars to > 100,000 miles, have changed the oil/filter myself on all of them, and have never had an issue due to the oil. These vehicles have included a number of makes and models and older vehicles (I still drive a 1966 Mustang daily) and newer vehicles. Also, for quite a few years I’ve been buying relatively inexpensive Chevron Supreme oil by the case at Costco. I’m open to the least expensive oil by a name brand oil company.</p>
<p>IMO the most important points are to always change the filter when the oil is changed and change the oil every 3000-4000 miles to get rid of any particulates and contamination that might be in the oil. If the choice is between synthetic oil changed infrequently and normal oil changed more frequently, I’d choose in favor of the more frequent changes.</p>
<p>For high stress engines such as high performance cars run hard you can’t beat synthetic. It gives more protection at high stress/temps. All racers use it. For everyday American cars not really needed. Most Japanese cars now come with it as do German cars.</p>
<p>YES!!! </p>
<p><em>Disclaimer: I work for an oil company that manufactures synthetic motor oil</em></p>
<p>[Synthetic</a> oil - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Synthetic_oil]Synthetic”>Synthetic oil - Wikipedia)</p>
<p>Thank you for input so far!</p>
<p>So far all the research seems to say within normal day-to-day operating conditions, there’s no difference between syn and conventional motor oil.
Argument for synthetics is favored when you are carrying high-load (eg towing a motorhome, car racing ), starting in extreme cold. I now live in the northeast when winter temp are sometimes in single digits. Is that a case for synthetics ? </p>
<p>Two other questions: 1) Why you can wait longer eg 10K instead of 5k for conventional motor oil ? 2) Why can’t you (I) switch based on season like regular 5-30W in summer, and synthetics 0-20W in winter ?</p>
<p>Going from synthetic to conventional can cause some cars to leak oil. I don’t know where these leaks occur - but that’s what everyone says.</p>
<p>Another concern is I hear of “synthetic tapping” - tapping of values or upper drivetrain it is not receving oil occur after eg, 70k. Not sure if that is individual cases. Have anyone experience or hear about this ?</p>
<p>I use synthetic (Mobil 1) for better protection and so I don’t have to change oil as often (myself). I won’t let jiffyLube or their ilk near any of my cars/trucks.</p>
<p>Two decade ago, Consumers Report did an oil study involving New York taxi cabs and various motor oils (conventional and synthetics). All the engines were rebuilt and critical moving parts were measured to provide a base line for comparisons. At the end of the test, all the engines were torn down and the various moving parts were re-measured to see what, if any wear, was detected with the use of different brands of oil. The conclusion: while some oils showed better wear characteristics than others, the differences were statistically meaningless as far as engine operation and longevity were concerned. Synthetic oils (Mobile 1) did fare better than conventional oils, but again, not enough to be statistically significant. The report did say that under some circumstances (towing or extremely cold temperatures), synthetics may be beneficial. The report went on to say that the traditional oil change intervals of three months or three thousand miles was overly conservative and that five thousand miles changes would be fine and save sending more used oil to the landfills. </p>
<p>As for synthetic oils causing leaks, this was true in the early 70’s when gaskets were designed to swell when in contact with conventional oils. Gasket materials have improved significantly and synthetic oils reformulated so this should not be a problem for cars and trucks built in the last twenty or so years. </p>
<p>That tapping sound (some GM truck engines come to mind) was caused by the engineering design. GM claims that the sound has no impact on either longevity or drivability. Some owners have switched to heavier oils which quiets the motor somewhat (at the expense of slightly lower fuel mileage). I haven’t read anything about engine failures because of the tapping. </p>
<p>As other posters have advised, conventional motor oils are fine for almost all applications. Your owner’s manual is the best guide for the type and weight of motor oil to use in your vehicle.</p>
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I hope not. I take my used oil back to the auto parts store used oil barrel to be recycled.</p>
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Unfortunately most of us don’t have one of those.</p>
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Really? That surprises me.</p>
<p>Most car manufacturers recommend you change your car’s oil every 5,000 miles, not every 3,000.</p>
<p>Anyone else have heard of synthetic oil tapping ?</p>
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<p>There is no difference between the engines in American and Japanese cars, with the exception of a few outliers (the GM pushrod V-8s and engines like the high-revving Honda S2000 come to mind). Virtually every passenger car engine is cast iron block or aluminum block with iron sleeves, and aluminum heads with single- or double-overhead cams, and two or four valves per cylinder. The country of brand origin won’t tell you much about the tech specs of the engine, or even where the engine was designed or built. Most German engines are the same too, except (again) for outliers like the V8 in the BMW M3 (over 8,000 RPM) and the Audi R8. If you eliminate high-rpm screamers and turbocharged engines, most gasoline engines today have similar specific outputs and construction. The implication that “American cars have primitive low-tech engines” is a myth.</p>
<p>(OK, some engines with aluminum blocks do away with the cast iron cylinder sleeves, but that seems like a pretty small distinction.)</p>
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I’ve always found the implication that pushrod engines are poor as a bad argument as well. The LS1-LS7 engine series proving that point quite well.</p>
<p>The smoothness and reliability of most Japanese engines still exceeds that of most US cars I have driven–and I travel a lot so I have rented just about anything made. Smoothness comes from tight specs and careful balancing of all components. Also at least Toyota ships all cars now with synthetic oil in the engine which was all I really said anyway. So does Porsche and probably BMW and Mercedes too. I don’t know which US cars ship with synthetic. I think Corvette does.</p>
<p>Well, I doubt we really want to get into a technical discussion on what creates “smoothness” for engines.</p>