Please Explain to me how changing the oil, increases wear for the next 1,000 miles

[SubieRubyRoo]

I think there is a problem with the methodology of the so-called tests that show wear increases during the first thousand miles.

What normally happens when you don't change your oil often enough? You get sludge build up. My hypothesis is that wear metals precipitate out of suspension and into that sludge and make it look like the rate of wear decreases as the oil ages. Then, when you change the oil, the fresh detergents "unstick" some of that sludge and particulates and that shows up as early increased wear metals found in used oil analysis.

If that were remotely the case or the true cause, it wouldn’t repeat the same results forever, which changing oil at 1k miles would. It is definitely related to the tribofilm and that different ZDDP levels & chemical interactions strip the previous protective layers (wear rate increases), the new ZDDP layer begins to form (wear rate plateaus), and the new ZDDP layer is protecting the surfaces (wear rates decrease as miles add, until the ZDDP is consumed from the oil and the wear rates begin to increase again).

This is why the longtime members look at multiple UOA samples of varying distances. You can’t tell much from too few samples, or all the samples from exactly the same distances & use patterns. You can only tell if the oil stayed in grade & had reserve TBN, and no fuel or antifreeze contamination.

 

[SC Maintenance]

There is a dry fill oil capacity (for a new engine) and a oil change capacity which is less. Some of the oil doesn't come out from a drain, and its typically a quart or so.

For example, if an oil change is 5 quarts, the engine may be holding 6 quarts. I seem to recall my VQ40 spec being over a quart more. Its buried way in the depths of the factory service manual.

So if I change the oil, I now have 5 quarts of new oil, and 1 quart of old oil, plus whatever wear materials were at the bottom of the pan, and all the other reasons above.

So the point being, a UOA at 1000 miles is all but worthless. Even if it is accurate - you have no idea what was from the last 1000 miles, and how much was from the old oil previously. Maybe if you did a UOA on the previous change, then did the 1000 mile stuff, then did a weighted average - possibly you could figure it out.

 

[Patman]

Wasn’t this website made in 2002? Or am I missing something

The forum in this format as a message board did start on May 27, 2002 however before that Bob Winters had a discussion board on his website that was very similar in format to the old newsgroups that used to be popular in the early days of the internet. So maybe he was there at that time? I was on there starting around 2000 I think but I’m not sure how long it had been going at that point.

 

[TimeFlies]

Thank you to everyone who posted.
This cleared it up somewhat for me, and yet I still take those tests with a grain of salt.
My dirt bike has no odometer, or hour meter, but gets an oil change about every 7or 8 hours, maybe 300 kms or so. My pickup, an f150 with V8 gets an oil change every 6 months, or 10,000 kms, whichever comes first. My semi trucks get an oil change approximately every 8 weeks, or 410 to 580 hours, or in kms that can be anywhere from 28,000 to 41,000 kms, depending upon the truck, run its on, etc.

 

[tcp71]

What if you always use the same oil? No "new chemistry" at work.

 

[ZeeOSix]

Automotive air filters do better after an initial layer of dirt forms.
I believe this phenomenon was conceptually applied to newly-in-service oil filters.

Yes, oil filters are more efficient when basically new, and loose efficiency (some filters worse than others) as they load up with debris due to increased dP across the media.

 

[Lockasiam]

The forum in this format as a message board did start on May 27, 2002 however before that Bob Winters had a discussion board on his website that was very similar in format to the old newsgroups that used to be popular in the early days of the internet. So maybe he was there at that time? I was on there starting around 2000 I think but I’m not sure how long it had been going at that point.

This makes it a lot clearer for me, thanks

 

[Lockasiam]

Yes, oil filters are more efficiency when basically new, and loose efficiency as they load up with debris due to increased dP across the media.

Don’t some of the multiple oci filters like the wix xp claim better efficiency when they have more crap in them

 

[ZeeOSix]

So the point being, a UOA at 1000 miles is all but worthless. Even if it is accurate - you have no idea what was from the last 1000 miles, and how much was from the old oil previously. Maybe if you did a UOA on the previous change, then did the 1000 mile stuff, then did a weighted average - possibly you could figure it out.

That's how it would be done - you have to have a starting baseline. Better yet, take a UOA at only 10 miles after an oil change and use that as the starting baseline to see how the ppm changes at planned UOA intervals after that. The data should be shown as ppm/1000 miles which makes it easier to compare.

 

[ZeeOSix]

Don’t some of the multiple oci filters like the wix xp claim better efficiency when they have more crap in them

I've never seen Wix claimed that from all the info I've ever read. It's been shown with test data that oil filters loose efficiency as they load up with debris. Like shown in this epic thread.

D

Post in thread 'Would you all like to see ISO 4548-12 Oil Filter Lab Testing Comparison, Efficiency & Capacity, Pressure vs Flow, Bubble Point, and Burst?'

Jun 4, 2021

Interestin

Yes, a pre Determined DeltaP determines the end of the test. In our case I choose 8PSID over clean assembly. For the ISO 4548-12 multipass test the average of readings taken every X seconds over a 5 min or 10 min time interval are averaged and reported depending on how long the test takes to reach that Terminal DeltaP.

What you see here in the previous graphs is an average taken from each time interval reading the entire time of the test and averaged. You can look at each time interval and see how it changes over time.
Here is an example of the AC-Delco time interval report...

• Davejam

• 

 

[Patman]

What if you always use the same oil? No "new chemistry" at work.

Even fresh oil of the same brand will temporarily remove that barrier because of it’s fresh additive package.

 

[ZeeOSix]

Even fresh oil of the same brand will temporarily remove that barrier because of it’s fresh additive package.

This is one of the logical theories on why some Ford Coyote V8 engines experience the infamous "BBQ tick" right after an oil change, because the friction level has changed by the new oil stripping off the existing tribofilm from the last oil run. Even when using the same oil. The change in friction level sets off the ticking on some Coyotes, if there's some kind of mechanical part sensitive to oil friction, like possibly the rod big ends "dancing" side-to-side on the crank journal at low RPM and banging against the end of the journal.

 

[Nessism1]

If fresh oil "strips off tribofilm", wouldn't that suggest that the detergents in the old oil were ineffective?. And given the high levels of calcium in most modern oils, that seems unlikely, unless the oil run is huge mileage.

 

[compratio10_5]

The ZDDP (zinc diakyldithiophosphate) requires heat & pressure to bond to engine surfaces, it forms a thin glassy layer (mainly on bearings, camshafts, & other high pressure lubricated areas)-and fresh oil scrubs it off, the layer takes a while to reform. The ZDDP EP layer fills in surface asperities & provides a hardened sacrificial layer that helps prevent cold start metal-on-metal contact. So, if you change your oil, and immediately get the engine hot, the ZDDP layer will start reforming. Or, if one changes the oil, & does a bunch of short trips without getting everything to operating temperature… Well, shouldn’t be too tough to figure out!

If this is the whole story, all you need is a good break-in trip after each oil change to reach the optimum state. Refer to SAE paper #2003-01-3119 and #2007-01-4133. I have wondered about this too.

 

[Exhaustgases]

And what is wearing? No need for EP for hydrodynamic plain bearings if protected by sufficient viscosity lube for cold starts. Just pistons and rings?
So like others say new oil, with detergent cleaning better? Viscosity plays huge as well.

 

[ZeeOSix]

And what is wearing? No need for EP for hydrodynamic plain bearings if protected by sufficient viscosity lube for cold starts. Just pistons and rings?

Any moving parts that's not in full hydrodynamic lubrication and has some level of metal-to-metal contact. That's where the tribofilm (ie the "film strength") is suppose to kick-in to mitigate wear, and if the tribofilm is lacking then there will be more friction and more wear.

 

[billt460]

Post #21 in this thread said the following:

Changing oil that often doesn't benefit the engines at all, and i mean 0, you may be even doing more harm than good, as each time you change the oil , the anti wear additives that bond to the metal in the engine are mostly washed away and then have to build back up again, this has been proven by measuring wear metals right after an oil change, and contrary to what logic would say, the wear actually tapers off as the oil gets some miles and time in the engine, obviously after enough time and miles the wear metals start to go back up again as the condition of the oil begins to degrade.

Thread '10 year old / 21k mile car with 3 verified oil changes'

Dec 14, 2024

Hello, all. I’m once again flirting with the idea of purchasing an older (2014) vehicle with very low original mileage (approx 21k). CARFAX shows 3 verified services on the vehicle; each approximately every 7k-ish miles meaning several years between as it was driven quite rarely. I assume the owner followed the OLM and the CARFAX states they did have it serviced at the original dealer.

I know there are issues with an older yet rarely driven vehicle with things aging out, but what - if any - danger was there from very larger periods of time but low miles between OCIs? Aside from the info...

• cammyfive79
• Replies: 55
• Forum: Passenger Car Motor Oil (PCMO) - Gasoline Vehicles

I don't buy it. At least not the part about new oil, "washing away the anti wear additives".... If the old oil leaves anti wear deposits on the metal, (like it should). How are they going to be "washed away" by new oil that contains far more of these ingredients, than the "old oil" it just replaced?

 

[RedSpider]

Would a brand new engine being supplied with a constant flow of fresh, never used oil, wear out quickly because the never ending flow of new oil is constantly fighting any buildup of tribofilm? Somehow I doubt it.

 

[PontiacHO]

That’s why engines that have stringent preventive maintenance always fail before those that are neglected. (SARCASM). Don’t believe everything you’ve been fed….

 

[notharry]

I would say most agree that an oil filter passes some larger particles at first and would be more effective after a few hundred miles and gradually become even more effective removing even smaller dirt afterwich it changes to becoming restrictive. I change my oil every 5000 miles. I seam to have more issues than someone that changes their oil every 7 to 10000 miles ( cam phasers guides tensioners chain) . To me, there may be something there but to what extent I dont know. Ill stay with the 5000 mile interval. I think im just more in tuned to problems before they become major is all. Perhaps someone has more solid testing on this. Yes Lake Speed the oil geek is great!! I found him a month ago on youtube.