Originally Posted By: J. A. Rizzo
No. UOAs seem to show very little difference in wear metals between modern motor oils, and there are plenty of non-oil-lubricated things on the engine that will probably fail before the major mechanical stuff anyway.
Just use whatever the manufacturer of the engine recommends and worry about something more useful, like spending more time with your kids or improving your job skills or volunteering for a worthy charity. Motor oil should be very near the bottom of the list of priorities in life, despite BITOG. The manufacturer doesn't want your engine to fail prematurely either, and they spent a lot of time a money engineering the thing to work a certain way for a certain time. I have no problem following their recommendations since I'm not an engineer. I paid them a lot of money to know what they were doing when they wrote the manual and built the engine. Why would I second guess that at the expense of my valuable time and money?
UOA's do not give you an accurate representation of how an engine is wearing. This is why manufacturers and oil companies use tear-down testing. BuickGN had no bearings left, but fantastic UOA's! Doug Hillary did tear-down testing at 1.2 million Km on one of his OTR trucks and everything spec'd within new. This was with 150ppm Fe as the condemnation limit for oil contamination in his UOA's! That engine is STILL going strong with 2.5 million on it now....
UOA's are a great tool for tracking oil life, contamination and looking for spikes in wear metals that MIGHT indicate an internal condition that needs to be looked at, but they are not a replacement for tear-down testing, and since they only sample a narrow spectrum of particulate size, they are not a good tool to monitor engine "wear" with. Doug's 150ppm limit would have most people on here who do UOA's having a stroke.... Tom NJ has also recently touched upon this topic.
A great analogy that was used a while ago was that using UOA's to monitor engine wear is like trying to use a blood pressure machine to predict heart attacks
Both tools are useful in their own right, but not very much so for the application depicted.
I concur with the second half of your statement completely. Use what the manufacturer recommends. The oil company and engine manufacturer do extensive field testing with tear-downs to monitor wear and oil life. Choosing a lubricant that falls within the range and specs listed by your manufacturer basically assures your engine will have a long life. To really capitalize on the benefits of a synthetic, one must be racing and/or running extended drains. Or starting their vehicle in incredibly cold conditions where a 0-weight is helpful.
