Oil get better with age (to a limit)?

[Razl]

---------------------------------------------
Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.
----------------------------------------------

This is an excerpt from Paradise Garage's Mobil 1 Test Results. http://neptune.spacebears.com/cars/stories/oil-life.html

Does this mean if I'm getting good UOA that I should keep the oil in as long as possible (7,500 - 10K miles)? I've also heard similiar theories with ATF but am on the fence. What are your thoughts?

[ June 23, 2004, 10:31 AM: Message edited by: Razl ]

 

[haley10]

I would like to read this SAE paper, but apparently it's not available for free.

As long as TBN is good and insolubles are low, I don't see any benefit to a change (even if no harm is done).

I think I can determine this myself thru uoa, rather than follow some blanket recommendation or especially GM's oil life monitor.

 

[goodvibes]

I think it also stated that the carbon in suspension worked in a positive way, similar to an add. I quess you would have to know which insolubles were in the oil to determine when to change. Still, if you do this repeatadly your engine would get mighty dirty.

 

[TC]

Interesting... As a faux spirit enthusiast, this makes me wonder, "Is motor oil more like beer or wine?" Beer starts to go south from the moment it's bottled -- fresher is better. Yet some wines mellow with age. I still say, "I'll take fresh motor oil with my fresh beer -- fresher is better!"

Booze notwithstanding, The AC Filter/Detroit Diesel SAE study determined that particulates in the 2-22 micron range cause most engine wear. Yet even the finest-rated PureOne filtered down only to 11 microns per Grease's study. The more an oil is used, the more those unfiltered 2 to 10+ micron particles accumulate, circulate, and cause wear. Then again, a filter which accumulates dirt actually filters BETTER by methodically sealing off pores, meaning only smaller and smaller particles may progressively pass, a fancy concept otherwise known as "clogging." Still, I'll take new oil and a new filter anyday.

 

[427Z06]

I remember reading a paper similar to this and from what I recall, the oil takes a certain amount of time to be "conditioned" to an operating environment. But this takes less than a 1,000 miles to happen. Something like 20 hours of use if I remember correctly.

 

[Ray H]

I've got an '89 Toyota 22-R-XXXX pickup sitting out front with well over 280,000 miles on the clock. Oil (whatever conventional 10W-30's cheapest on the shelves at Wally*World) and Pep Boys or ST filter changed faithfully every 3,000 miles. Neither drips nor burns oil. After reading this thread, I can only conclude the motor's about shot so I should junk it, eh? This site is so educational...

[ June 24, 2004, 01:19 PM: Message edited by: Ray H ]

 

[Razl]

I would love to see some data on by-pass filter users comparing wear rates since this would keep particles below the 5 micron level in check:

Group #1 - Does NOT do OCI, only filter changes and top offs

Group #2 - Always performs OCIs around 5,000

 

[MolaKule]

quote:

---

I read that mobil 1 18,000 mile life test. In simple terms....cant it just be the oil, in its early 3000 miles doing its job better and picking up more wear metals, and so on, so it appears that there is more wear going on in the first 3000 miles, but there really isnt?

---

I agree with Redwolf.


The Dispersant/Detergent (DD) package is strongest in concentration when the oil is new. I think the new oil's DD package is solving the "left-overs" from the old oil, since the old oil's DD package couldn't suspend as much stuff toward the end of it's life.

New, fresh oil will always do better than an oil whose life is about to end.

[ June 24, 2004, 02:30 PM: Message edited by: MolaKule ]

 

[Kestas]

If used oil truly did a better job than new, don't you think that oil manufacturers would blend old oil with new to take advantage of this fact? We already have a cheap source of used oil from all the collection places. I don't think manufacturers would overlook such a simple way to save money and increase quality at the same time.

 

[427Z06]

Well...I wouldn't get carried away here. I doubt that sheared out, insoluble and fuel ladened oil is better than unconditioned new oil.

 

[tpi]

quote:

---

Originally posted by TC:
Then again, a filter which accumulates dirt actually filters BETTER by methodically sealing off pores, meaning only smaller and smaller particles may progressively pass, a fancy concept otherwise known as "clogging." Still, I'll take new oil and a new filter anyday.

---

That would be my thought too, plus the dirt introduced during the oil change. It would be interesting to see the QC/cleanliness in the oil filter plant. Dirt/debris in the new filter is pumped directly to the bearings.

 

[RedWolf4000]

I read that mobil 1 18,000 mile life test. In simple terms....cant it just be the oil, in its early 3000 miles doing its job better and picking up more wear metals, and so on, so it appears that there is more wear going on in the first 3000 miles, but there really isnt? Or am i not understanding somthing right?? I find it hard to believe that engine wear mostly occurs within the first 3k of your oil, when the people who change there oil at 3k keep there cars forever, and the slackers who change there dino when they feel like it, after the dino is totally destroyed, has engines burning oil at 75k miles.