I am still quite confused by the true meaning of wear metals in UOA's. Are they directly related to engine wear? Are they strongly correlated to engine wear? Is there just a loose correlation to engine wear?
carock said:Nope - does not prove what you believe it does. If you think these are good evidence, then I ask you to give direct, specific citation (page and paragraph) so that I can counter your points.
NONE of those studies compares/contrasts how one properly managed system performs relative to the alternative. All these studies you folks point to are one-sided; they only study how things are viewed relative to the manipulation of the criteria for the bias of the bypass system.
I have yet to see one single study that shows how a typical FF system (managed to its best result) compares/contrasts to a BP (also managed to its best result), in moderate OCIs.
710813 - Pages 12 Figures 23 and 24 compares FF to FF and BP actual on the highway, no loaded sumps, real oil, normal OCI, of dump trucks over 120,000 miles. Read the article carefully, they almost sneak this test in as an afterthought. "Also included in these test data are comparisons with the wear obtained in the truck test using the 40 micron full flow filter and the 40 micron full flow filter in combination with the bypass filter. The results of the truck test with no intentional contaminant fed to the engine crankcase showed definite reduction in all engine component wear, but the percentage reduction was less than the dynamometer tests."
840453 - Figure 7 "Road Test With Standard Filtration Compared to Double Filtration " meaning FF to FF & BP. This compares the actual measured wear rates of road going delivery trucks with no special treatment to the oil. Wear is reduced around 50%.
902238 - Figure 7 FIlter "C" is the FF & BP combination with a 3 micron bypass. Notice wear is less than 50% of the 20 micron FF "B" and about 10% of the 40 micron FF "A". Read the whole article carefully. The 3 micron filter is a bypass filter, not a full flow filter.
"Bypass filtration, when used in conjunction with full flow filtration, provides an additional level or protection in terms of further reduced particle concentrations". The particle concentrations they are talking about are wear metals determined by full particle counts of each metal.
These articles all have real world tests in real world trucks with no loading the sump with abrasives and regular OCI's. They all have similar results. If this isn't proof what is? I have even more convincing tests from filter manufacturers, but they sell the things.