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

[twX]

I notice in the PDF about tribofilms, all of the sources posted are all pretty old (mainly early 90's and a couple 70's) and talking about (mostly) ZDDP - is there any newer studies on this? Seeing how a lot of newer oils have gone away from it or very small amounts

The subject has become a lot less important as the industry has moved towards roller tappet valvetrain designs, which aren't very dependent on ZDDP.

The most recent study I'm aware of that relates to the anti-wear properties of aged oil is SAE 2007-01-4133. Like earlier studies, it was focused on flat tappet valvetrain wear.

 

[OVERKILL]

The subject has become a lot less important as the industry has moved towards roller tappet valvetrain designs, which aren't very dependent on ZDDP.

The most recent study I'm aware of that relates to the anti-wear properties of aged oil is SAE 2007-01-4133. Like earlier studies, it was focused on flat tappet valvetrain wear.

You might find this interesting:
https://link.springer.com/article/10.1007/s11249-020-01315-8

While the need to protect exhaust aftertreatment systems continues to be the main motivation for seeking replacements for ZDDPs as engine oil antiwear additives, other reasons have also emerged. In the 1970s it was noted that ZDDPs contribute to reduced engine fuel economy [5] and it was found that this resulted primarily from an increase in friction in mixed lubrication conditions, as present in parts of the piston ring/liner sliding and the cam-follower rolling-sliding contact cycles [6]. It is now recognised that this increase in mixed friction originates primarily from an increase in effective surface roughness of the surfaces due to the pad structure of ZDDP tribofilms [7].

In recent years there has been an increasing problem of micropitting wear [8]. This is a form of fatigue wear in which the cyclic stresses that result when asperities on opposing surfaces coincide drive the growth of tiny, surface-originating cracks, with subsequent loss of the undermined material as micron-scale wear particles. These asperity stresses occur in high pressure contacts when surfaces are separated only by very thin lubricant films and are thus becoming more prevalent as lubricant viscosities are reduced in the quest for improved fuel economy. Although micropitting is primarily a mechanically driven process it has been found to be accelerated by ZDDPs [9,10,11]. This is because ZDDPs inhibit running-in, by forming tribofilms so rapidly that asperities present on the surfaces from manufacture do not have time to be smoothed or rounded. The consequent survival of relatively sharp asperities means that high asperity stresses persist for the life of the component, promoting micropitting wear.

 

[ZeeOSix]

The subject has become a lot less important as the industry has moved towards roller tappet valvetrain designs, which aren't very dependent on ZDDP.

In those old flat lifter on cam lobe engines I have to wonder just how good the flat lifter material was and how well it was heat treated on the contacting face for wear robustness to begin with. More modern engines that use direct cam lobe on bucket/shim over valve stem don't seem to have any issues with today's modern oils and the reduction of ZDDP, as those buckets or shims are very hard due to heat treatment, like a cam lobe would be. But as @OVERKILL mentioned earlier, there have been reformulations of the AF/AW additives like using Moly having a good synergy with the ZDDP to get adequate, and maybe even better AF/AW performance overall.

 

[grampi]

Well, now that the resident tribological authority has weighed-in, the matter is clearly settled. Disband the SAE folks!

If it does occur, it certainly hasn't hurt my '04 Corolla with 450K miles, which has had approx. 75 oil changes over its life span...

 

[Creekside]

So I’m reaching back in time to my college years here but we had a program from Cummins I think that talked about frequent oil changes being detrimental to engines. Most if not all OTR engine manufacturers don’t want you to pre fill oil filters and that can require the engine to move up to a gallon of oil in some cases before system pressure ever comes up and the engine is fully supplied with oil again. Now if you take an engine that runs a a million or more miles would that ever have a noticeable difference in engine life? I have no idea. I pre fill every filter that I can so I wouldn’t know anyway.

 

[OVERKILL]

If it does occur, it certainly hasn't hurt my '04 Corolla with 450K miles, which has had approx. 75 oil changes over its life span...

Of course it doesn't hurt, if you read the comments in the thread you'd understand it's almost a wholly academic exercise because the "increase" is insignificant in terms of its impact on the life of the equipment.

It's like using insanely efficient oil filters, or Donaldson Powercore air filters, both of which definitively reduce wear. But your typical car engine lasts just fine on dealer filters and OE air filters. Heck, even with the K&N rock catcher air filters, folks get long engine lives. A lot of things that increase wear don't do so at a level that's going to be evident to Joe Average.

 

[BHopkins]

Of course it doesn't hurt, if you read the comments in the thread you'd understand it's almost a wholly academic exercise because the "increase" is insignificant in terms of its impact on the life of the equipment.

It's like using insanely efficient oil filters, or Donaldson Powercore air filters, both of which definitively reduce wear. But your typical car engine lasts just fine on dealer filters and OE air filters. Heck, even with the K&N rock catcher air filters, folks get long engine lives. A lot of things that increase wear don't do so at a level that's going to be evident to Joe Average.

If everyone here on BITOG would not only understand this, but take time to ponder it, and comprehend it, we would eliminate a vast majority of redundant debate here, on so many subjects.

 

[Patman]

If it does occur, it certainly hasn't hurt my '04 Corolla with 450K miles, which has had approx. 75 oil changes over its life span...

That averages out to an oil change every 6000 miles so that doesn’t prove anything here considering we are talking about oil changes that are done way more frequently than that.

 

[grampi]

That averages out to an oil change every 6000 miles so that doesn’t prove anything here considering we are talking about oil changes that are done way more frequently than that.

That's a waste of good oil...

 

[Patman]

That's a waste of good oil...

I agree. I change my Corvette around 7000 miles and my Civic every 9-10k.