Are UOA really valid?

Messages
687
Location
Canada
There seems to be a big differance between VOA's and UOA's taken on the same vehicle in series seem to be all over the place. What gives? Iam begining to think they are for entertainment purposes only as they simply are not accurate enought to be certain about anything.
 
Messages
3,693
Location
Chattanooga, TN
quote:
Originally posted by Jason Troxell: There are many variables and if you don't have all info, it may seem that way. That's why interpretation is important. If something varies from the trend there is a reason for it. And the reason is not UOA are worthless. There are plenty of extrememly consistent trends on here to show the consistency of UOA.
I think the real question is "so what" Whatis one to do if something varies from the trend other then the obvious coolant leak (notice that anyway with coolant loss) or air intake leak. Basically, there isn't much that one can do about it and the larger issue is, does it really impact the longevity of the engine. 99% of the time no and just look at the engines with 200,000 plus miles and never had an analysis. IMO, UOA nice to have if you have the interest, the time and especially the money. Otherwise, just keep on trucken and you will not see any difference in the longevity of your vehicle. Sort of like having your blood work done every six months to play it safe but 99% of the time other symptoms will show up that will cause you to see a doc and have your problem looked it. Hemoglobin and hematocrit way too low, cheez, think that is why you are tired all the time.
 
Messages
47,693
Location
Duvall WA - Pacific NW USA
First and foremost, I think a UOA can be used to tell you if you have a real problem (hopefully just begining, if you do have a problem). That alone makes a UOA worth the cash. OTOH - seeing people argue about 15ppm vs. 20 ppm Fe on a different car, on a different oil, measured 2 years apart, at different labs, at different mileages....is indeed very entertaining. [Big Grin]
 
Messages
3,593
Location
Outside smalltown, IL
If you are running extended drains I don't see any way other than periodic UOA's to make sure the intervals you've chosen are acceptable. Too many variables with different oils, engine types, driving conditions, etc. to just guess...
 
Messages
43,648
Location
'Stralia
as jsharp suggested, they are the only way to tell if your extended drains are safe. I've got issues with uoa and bypass filters. The bypass filteres are supposed to removed all contaminants and wear particles. Your engine could be wearing poorly, and uoa could show great results.
 
Messages
3,649
Location
St. Charles County, Missouri
1. I think lab to lab variations are considerable. 2. Winter can result in far more wear than summer driving. 3. I think some brands of oil are not as steady across production runs as some brand loyalists would like you to believe.
 
Messages
463
Location
Palatine, IL
I think there are far too many variables in the equation to make scientific decisions regarding Motor Oil performance from UOA reports on street vehicles. Perhaps an educated guess is the best than can be achieved.
 
Messages
2,095
Location
IL
There are many variables and if you don't have all info, it may seem that way. That's why interpretation is important. If something varies from the trend there is a reason for it. And the reason is not UOA are worthless. There are plenty of extrememly consistent trends on here to show the consistency of UOA.
 
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