PART 5: ENGINE WEAR PARTICLES CAUSE OIL CONTAMINATION
Ok, so we've taken care of the air intake, but what about metal particles from engine component wear? Well, there are a couple of things going on here that lead to better protection from a synthetic oil. One aspect that proves to be very important is cold weather starts. Now, all of us have heard about cold weather starts for years from oil additive manufacturers. We've all heard, "Just put our additive in your crankcase and it will form an impenetrable layer over engine components that will protect your engine against wear, especially at start-up. In fact, it's so good, you could even drain the oil from your engine and drive it around the track a million times at 60 mph."
Hogwash. Just about all of the companies that have made claims like this over the years have been brought up on charges by the FTC. They're full of it. However, they were right about one thing. Cold-weather starts are killing your engine. Consider this:
The pour point of an oil is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. That's tech-talk which basically means that the pour point of an oil is the point at which it ceases to be "pourable". This measurement is especially important for oils used in the winter.
A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain "adequate" oil flow and pressure within an engine. This is not provided by a lot of the manufacturers, but generally seems to be about 20 degrees F above the pour point. So, the lower the pour point the better.
Most petroleum oils have pour points in the range of -15 to -35 degrees F. That means that their borderline pumping temperature is, at best, around -15 degrees F and probably closer to 5 to 10 degrees F. So, if you're running a petroleum oil, don't expect to go out and start your car at 0 degrees and have it purr like a kitten. It's going to spit and sputter and kick and scream for a few minutes.
Why do you think that is? It's not getting any oil up into the engine. It's like trying to suck molasses through a tiny straw in an Alaskan January. There's literally nothing keeping the metal components in your engine from tearing each other apart. Every time you start your engine in conditions like this, your engine dies a little bit more.
Synthetic oils, on the other hand, routinely have pour points around -40 degrees or colder. Some have pour points as low as - 60 to -70 degrees F. Granted, there are very few of us who will ever have to start our car at this temperature, but imagine how well these oils lubricate at -20, if it they still flow at -70.
Now, I know that some of you live in areas where you almost never see temperatures under freezing. For you folks, the pour point of your oil may be a little less important, but it still serves to prove a point about the protection differences between petroleum oils and synthetics.
In addition, lets get back to that impenetrable barrier over your engine components that oil additive manufacturers sputter about all the time. Although, there is no scientific testing that proves this will really occur in actual automotive applications when using an oil additive, synthetic oils do provide something similar to this.
Generally, a thin film of synthetic oil will remain on engine components for days after it was last run. Petroleum oils tend to drain back down to the oil pan very quickly, leaving no oil film to protect your engine at start-up. Many auto techs and backyard mechnics can attest to this after doing engine tear- downs. Those using synthetic oil generally will have a thin film of oil left on components even if the engine has been sitting for awhile.
It's certainly not impenetrable, and I wouldn't go draining your oil after installing 6 quarts of synthetic just to see if your engine still runs, but it does serve a purpose. Your engine should virtually NEVER see metal to metal contact, whether in hot or cold climates. That's something that a petroleum oil can't do.
In addition, because of the higher film strength and better lubricity characteristics of synthetic oils, they routinely perform better on standardized ASTM wear scar tests. This would indicate a higher level of engine protection and would certainly lead to fewer engine wear particles in an engine. Hence, fewer contaminants in the oil to necessitate changing it.
Excerpted with Permission from "The Motor Oil Bible" eBook
Copyright 2000 Michael Kaufman ("The Motor Oil Bible" Author)
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