Wear vs Viscosity

[Al]

Has anyone read any articles relating engine wear vs viscosity. I have not. It appears to me that if there is wear with say a 20 wt or 30 wt oil the wear "should" be proportional to the viscosity. ie viscosity of id 20 wt- 8.5 cSts and 30 wt- 10.5 cSts. 25% more wear with 20 wt. oil vs. 30 wt.

 

[Nessism1]

No. Wear is typically similar, or identical.

 

[kschachn]

Been discussed multiple times in many long and detailed threads, wear is directly related to HT/HS.

Hint, "thick vs. thin" threads. I bet you've participated in them.

 

[Plumb Bob]

Two decades and counting. That has been one of the most discussed topics on BITOG.

 

[Glenda W.]

 

[skyactiv]

How many of us have worn out an engine on a passenger vehicle we bought new? I'm not talking about a seasoned citizen that bought a new 63' Plymouth. The days of ring jobs are virtually a thing of the past. Bad engineering, poor manufacturing and corporate bean counters cause today's problems, not 0W20 vs 5W30.

 

[TurboZedd-R]

You won't own a car long enough or a chassis won't last long enough to notice a difference between 20wt and 30wt in a commuter making 50-70hp per cylinder, at best.

 

[Jetronic]

How many of us have worn out an engine on a passenger vehicle we bought new? I'm not talking about a seasoned citizen that bought a new 63' Plymouth. The days of ring jobs are virtually a thing of the past. Bad engineering, poor manufacturing and corporate bean counters cause today's problems, not 0W20 vs 5W30.

chains wear out though, and conrod bearings still do, especially on turbo cars.

 

[kschachn]

You won't own a car long enough or a chassis won't last long enough to notice a difference between 20wt and 30wt in a commuter making 50-70hp per cylinder, at best.

I bet I have.

 

[TurboZedd-R]

I bet I have.

Betting normally involves an outcome that is measurable and observable. So, do you own a car that the chassis has outlasted an engine that "wore out" due to a 20wt that could have been avoided with a 30wt?

I bet you don't.

 

[kschachn]

Betting normally involves an outcome that is measurable and observable. So, do you own a car that the chassis has outlasted an engine that "wore out" due to a 20wt that could have been avoided with a 30wt?

I bet you don't.

Wear is directly correlated to HT/HS, so using an oil with a higher grade will help the engine to last longer. Do I think I would have gotten nearly 500k out of my old 1MZ-FE using a 20-grade? Perhaps it may still be operating but my leak down numbers were pretty good at 400k or so.

But then again I’ve used a 40-grade with Euro approvals nearly all the engine life so it’s not really comparable to a 30-grade ILSAC. So there’s that.

 

[TurboZedd-R]

Wear is directly correlated to HT/HS,

Which is pretty common knowledge, just use the search.

so using an oil with a higher grade will help the engine to last longer. Do I think I would have gotten nearly 500k out of my old 1MZ-FE using a 20-grade? Perhaps it may still be operating but my leak down numbers were pretty good at 400k or so.

But then again I’ve used a 40-grade with Euro approvals nearly all the engine life so it’s not really comparable to a 30-grade ILSAC. So there’s that.

I was asking can you prove an engine will not outlast a chassis using 20wt but all of a sudden it will outlast a chassis using a 30wt. You said you bet yes? I don't see any evidence.

 

[cryptolyme]

higher viscosity also increases friction. guess there is a balance.

 

[Al]

higher viscosity also increases friction. guess there is a balance.

Viscous friction is different than dry friction.

But it was a question with a false premise. The anti wear additives make all the difference. But lets compare 2 different viscosity oils with no additives.

I designed a device which will vary load, viscosity, and speed...while measuring resulting friction and wear, and temp. I now of no existing device that can do that. I am submitting it to PSU engineering for their evaluation and possibly, use it as a doctorate thesis. We'll see.

 

[wpod]

Thicker oil, all things equal protects better until it doesn't.

 

[Al]

Thicker oil, all things equal protects better until it doesn't.

Yea. Different ways to look at it.

 

[kschachn]

Thicker oil, all things equal protects better until it doesn't.

When doesn’t it?

 

[Triple_Se7en]

Thicker oil, all things equal protects better until it doesn't.

I consider thicker oil as one step up.
I consider thick oil as going two steps up.
I consider thickest oil as 'think hard and think twice' before stepping on any rungs of that ladder.

 

[02zx9r rev2]

Which is pretty common knowledge, just use the search.

I was asking can you prove an engine will not outlast a chassis using 20wt but all of a sudden it will outlast a chassis using a 30wt. You said you bet yes? I don't see any evidence.

He can’t

 

[Al]

He can’t

On my 3 subaru forums I have seen many occurrences where folks previously using 20 wt. oil shift to 30 wt. because their consumption went up. Hide and watch. No thanks.