This is interesting stuff regarding
oil age. And it makes enough sense. Not sure if that means I'm willing to forgo an annual
oil change...
On the other side of the coin, I recall a fairly recent article. A big name mfg, (want to say, Volvo?) basically put forth the idea that
oil doesn't really go bad by itself, it is the accumulated broken down components of everything else that ruins oil over time/mileage. Metals, moisture, fuel blow-by, dirt, pollen, etc. act as contaminants.
I suppose to validate this they designed some super-duper oil filtration system. Then filled up one of their semi trucks and ran it for a million miles. At normal oil change intervals the old oil was run through said super filters and replaced into the semi.
I do think the jist of it was just what was stated, with sufficient filtration, the oil performance never degraded appreciably over the test. After being "properly" filtered of contaminants the used oil performed as well as new.
So I guess if you had a good enough oil filter system you could run the same oil "forever" just replacing the bit consumed over time by combustion and unrecoverable from your filters.
But again, I'm not going to volunteer to be first in line for that experiment.
Edit: After posting I decided to go look it up because I don't want to be the source of a mis-truth on the internet.... I can't find any 1 article referencing Volvo conducting this experiment. What I can find is a 'test' sponsored by "Safety-Kleen" (a producer/seller of "re-refined" engine oil) did a comparison between a truck running its recycled oil vs one running virgin oil. And separately I see some trucking fleets have installed a system that filters oil at 1 micron and burn/scavenges the waste, and at least 1 company running that system is claiming t get nearly 200,000 miles between changes.
So, objectivity aside both cases do seem to support the notion that 'clean' oil is more important than 'new' oil.