Confessions of a Recovering Thickie

[ZeeOSix]

Good post, but I have no idea how it related to my point on *clearances* being minimized.

The gist of the post was to show that thinner oils result in less uniform pressure distribution, regardless of the bearing clearance. And bearing clearance has nothing to due with load bearing capability. What determines that is the bearing area and the pressure of the oil in the MOFT oil wedge. If the combination of bearing area and viscosity are not capable of supporting the rod load, then the MOFT goes to zero, then wear & damage occurs.

 

[ZeeOSix]

If you think the ESP will provide better protection and oil pressure than Mobil 1 0w-40 FS then I might be willing to try it.

Oil pressure only ensures that adequate volume is moving and being supplied to the parts that need it. Oil pressure has nothing to do with providing a supporting film of oil pressure between moving part, not really even in journal bearings (super negligible as mentioned earlier - see graph in post 272).

 

[ZeeOSix]

With the Rogue I'll confess that I have put 5w-30 in it once. Only once. Idea was to get better protection. See, I've already had this thick vs thin discussion with myself. The reasoning is that Nissan not only recommends but requires 0w-20 in that engine.

You have a shot of the OM where it says 0W-20 is "required"?

 

[siriusc1024]

Oil pressure only ensures that adequate volume is moving and being supplied to the parts that need it. Oil pressure has nothing to do with providing a supporting film of oil pressure between moving part, not really even in journal bearings (super negligible as mentioned earlier - see graph in post 272).

Sir, you're talking to a guy who installed a high pressure oil pump to ensure higher pressure. Higher pressure means more volume. If I'm dropping to 30psi idle after a WOT run or even stop-and-go traffic on a hot day, and the valves start to clatter, that indicates a problem. I have that issue with certain oils but others no.

You have a shot of the OM where it says 0W-20 is "required"?

They recommend the Nissan oil. They say anything other than 0w-20 synthetic will cause damage - I read that as a requirement.

 

[chris719]

They recommend the Nissan oil. They say anything other than 0w-20 synthetic will cause damage - I read that as a requirement.

Good thing you're not a lawyer. It's a CYA, they are just saying that if you deviate you are responsible, not them. They are not saying that deviating will cause damage. They are saying that damaged caused by deviation is not covered by warranty. The first line literally says recommended anyway. That's not a requirement, it's a recommendation. You could run 10W-60 in this thing and nothing would happen.

 

[siriusc1024]

Good thing you're not a lawyer. It's a CYA, they are just saying that if you deviate you are responsible, not them. They are not saying that deviating will cause damage. They are saying that damaged caused by deviation is not covered by warranty. The first line literally says recommended anyway. That's not a requirement, it's a recommendation.

Really. How do you know they don't want the engine to last? They are saying use the spec so it lasts. You didn't design the engine. On what basis do you make that assumption? Do you suggest I gamble engine life based on said assumption?

 

[ZeeOSix]

Very good info on pressure distribution and relationship to viscosity. Hadn't considered that, but I'll keep it in mind from now on.

Notice also they mention decrease clearance to compensate. Another design feature with viscosity in mind. Do you think there are any risks of inadequate lubrication for bearings clearanced with thinner oils in mind?

Yes, as that graph shows the supporting oil wedge pressure distribution difference becomes smaller as the bearing clearance decreases. Most rod bearings are going to have around 0.001 to 0.002 inch clearance.

Like said throughout this thread, any bearing will produce less MOFT with thinner oil viscosity. That's just how journal bearings work. So the main thing is to ensure the MOFT is more than adequate (not on the ragged edge) for all possible driving situations. This is exactly why I will go a grade up on anything specifying a xW-20 or less. MOFT headroom is free and does add more engine wear protection. Nothing says any different.

 

[BornSlippy]

Really. How do you know they don't want the engine to last? They are saying use the spec so it lasts. You didn't design the engine. On what basis do you make that assumption? Do you suggest I gamble engine life based on said assumption?

View attachment 280698

What year Rogue?

 

[ZeeOSix]

Sir, you're talking to a guy who installed a high pressure oil pump to ensure higher pressure. Higher pressure means more volume. If I'm dropping to 30psi idle after a WOT run or even stop-and-go traffic on a hot day, and the valves start to clatter, that indicates a problem. I have that issue with certain oils but others no.

They recommend the Nissan oil. They say anything other than 0w-20 synthetic will cause damage - I read that as a requirement.

View attachment 280694

Says "recommended", not "required". Their statement that warranty won't be covered if other oil is used is a blanket CYA statement. They could be talking about someone using an old API spec, or even someone using an oil thinner than 0W-20, or using a "W" rating higher than 0W in super cold environments. All kinds of things. I'd like to hear them argue in court how a higher KV100 caused damage ... they really couldn't because it doesn't. Nothing points to engines being damaged from running a grade or two above a XW-20.

 

[siriusc1024]

Says "recommended", not "required". Their statement that warranty won't cover if other oil is used is a blanket CYA statement. They could be talking about someone using an old API spec, or even someone using an oil thinner that 0W-20 or using a "W" rating higher than 0W. All kinds of things. I'd like to hear them argue in court how a higher KV100 caused damage ... they couldn't because it doesn't.

View attachment 280699

Think they could prove to the court that deviating from spec is enough to void warranty should the engine fail? In that situation, with me being the plaintiff, it's on me to prove that they're wrong. I can't. Can you? How about you, chris from bitog?

Besides, you can read it. Read it literally without inserting an opinion or bias. It says engine damage may result with the wrong viscosity here and the other page I posted. It does. Sorry.

Again. Prove otherwise. You'd have to know some specifics beyond blanket statements about engines that have bearings and pistons and stuff.

 

[ZeeOSix]

Really. How do you know they don't want the engine to last? They are saying use the spec so it lasts. You didn't design the engine. On what basis do you make that assumption? Do you suggest I gamble engine life based on said assumption?

View attachment 280698

Says "satisfactory engine life", not "ultimate or maximum engine life". All they have to do it get you through the warranty period.

 

[ZeeOSix]

Think they could prove to the court that deviating from spec is enough to void warranty should the engine fail? In that situation, with me being the plaintiff, it's on me to prove that they're wrong. I can't. Can you? How about you, chris from bitog?

First of all, the engine won't fail from using a grade or two higher KV100. Millions of cars are doing it, and how many dead engines from doing that have you seen reported? Based on what I know of lubrication and how viscosity behaves in an engine I think they'd be hard to prove it was thicker oil that caused the problem. I'd ask them to show me controlled studies that prove that higher KV100 damages engines, and I'd show every study that shows less wear from higher viscosity. Besides, you'd have to be fool like running a too thin oil in a track use scenario to get an engine to be very damaged or fail. And car makers don't warranty cars used for track days. The cause of engine damage is otherwise going to be lack of oil supply volume and therefore lack of lubrication. A car manufacture would probably try to blame the oil when actually the oil pump failed, lol.

Besides, you can read it. Read it literally without inserting an opinion or bias. It says engine damage may result with the wrong viscosity here and the other page I posted. It does. Sorry.

I doesn't actually say the words "engine damage may result with the wrong viscosity" ... that's what you are inferring from a general statement. They are simply making a CYA statement that if the "recommended" oil is not used, then warranty can be denied. They could be referring to the API spec more than the viscosity. it pretty nebulous because they "recommend" a viscosity. If they are were that stingint about warrantly they should say something like: "0W-20 is required".

Again. Prove otherwise. You'd have to know some specifics beyond blanket statements about engines that have bearings and pistons and stuff.

Lots of the info I've posted in this thread shows the benefits of higher KV100/HTHS viscosity. All moving parts create more MOFT with higher viscosity. More MOFT gives more wear protection ... nothing changes that. And obviously some engine makers have learned that first hand and therefore increased the recommend oil viscosity.

 

[siriusc1024]

Says "satisfactory engine life", not "ultimate or maximum engine life". All they have to do it get you through the warranty period.

Yeah that's it. Nissan is willing to risk being known as the company whose engines only make it 60k in order to meet the EPA's requirements.

 

[ZeeOSix]

Yeah that's it. Nissan is willing to risk being known as the company whose engines only make it 60k in order to meet the EPA's requirements.

They used the word "satisfactory" for a reason. Another way to say it would be "just good enough to meet the goal". Bet if CAFE wasn't driving their "recommended" viscosity, you'd see a whole range in the OM like the same engines used in other countries.

 

[siriusc1024]

First of all, the engine won't fail from using a grade or two higher KV100. Millions of cars are doing it, and how many dead engines from doing that have you seen reported? Based on what I know of lubrication and how viscosity behaves in an engine I think they'd be hard to prove it was thicker oil that caused the problem. I'd ask them to show me controlled studies that prove that higher KV100 damages engines, and I'd show every study that shows less wear from higher viscosity. Besides, you'd have to be fool like running a too thin oil in a track use scenario to get an engine to be very damaged or fail. And car makers don't warranty cars used for track days. The cause of engine damage is otherwise going to be lack of oil supply volume and therefore lack of lubrication. A car manufacture would probably try to blame the oil when actually the oil pump failed, lol.


I doesn't actually say the words "engine damage may result with the wrong viscosity" ... that's what you are inferring from a general statement. They are simply making a CYA statement that if the "recommended" oil is not used, then warranty can be denied. They could be referring to the API spec more than the viscosity. it pretty nebulous because they "recommend" a viscosity. If they are were that stingint about warrantly they should say something like: "0W-20 is required".


Lots of the info I've posted in this thread shows the benefits of higher KV100/HTHS viscosity. All moving parts create more MOFT with higher viscosity. More MOFT gives more wear protection ... nothing changes that. And obviously some engine makers have learned that first hand and therefore increased the recommend oil viscosity.

And I've pointed out a possibility, requiring piston ring coatings, that thicker oil leads to more wear. So that's one of the specifics. Does that engine have ta-C coated piston rings?

Here's a specific I found. The bores are mirror polished. No cross-hatching. Not sure what to make of that beyond another design feature to improve mpg. Nissan knows how to optimally lubricate here. I don't. Does that also imply ta-C piston rings? Maybe.

 

[Shel_B]

AKA euro oil. Right back where we started.

You're a real smarty-pants ...

 

[ZeeOSix]

And I've pointed out a possibility, requiring piston ring coatings, that thicker oil leads to more wear. So that's one of the specifics. Does that engine have ta-C coated piston rings?

Here's a specific I found. The bores are mirror polished. No cross-hatching. Not sure what to make of that beyond another design feature to improve mpg. Nissan knows how to optimally lubricate here. I don't. Does that also imply ta-C piston rings? Maybe.

That ring coating cherry pick is just something to grasp onto to justify thin oil. As said before, special coatings are a thing with engines specifying super thin oils because they use the coating to mitigate wear when the MOFT goes to zero and the film strength can't pickup all the slack. From what I say it was pretty meaningless in the grand scheme of engine lubrication. I really don't care what you or anyone uses in their engines, I just discuss the technical aspects of how viscosity behaves in an engine, and don't care if anyone see it the same way or not. They can do their own research, or just use what the OM says.

So have you went searching for the OM of that same Nissan Rogue engine uses ion other counties to see what oil viscosity they "recommend"?

 

[Shel_B]

Honestly I’d step up to the ESP 0w30 in both, not only for simplicity but also to keep those engines and pistons clean. Dexos has a hard time in that department. I’m dealing with a clean up test as we speak from QS 0w20 synthetic on 5k oci’s.

How's that coming along? I've been sorta following, but have surely missed a lot.

I've commited to using HPL for a while since the oil is already here, but after I may want to swing back to M1 and use one of the ESP XW-30 variants instead of the EP that I've been using.

 

[siriusc1024]

How's that coming along? I've been sorta following, but have surely missed a lot.

I've commited to using HPL for a while since the oil is already here, but after I may want to swing back to M1 and use one of the ESP XW-30 variants instead of the EP that I've been using.

Yes, please updates. I'm interested in your findings. Do you have a link?

 

[siriusc1024]

That ring coating cherry pick is just something to grasp onto to justify thin oil. As said before, special coatings are a thing with engines specifying super thin oils because they use the coating to mitigate wear when the MOFT goes to zero and the film strength can't pickup all the slack. From what I say it was pretty meaningless in the grand scheme of engine lubrication. I really don't care what you or anyone uses in their engines, I just discuss the technical aspects of how viscosity behaves in an engine, and don't care if anyone see it the same way or not. They can do their own research, or just use what the OM says.

So have you went searching for the OM of that same Nissan Rogue engine uses ion other counties to see what oil viscosity they "recommend"?

And again. The coatings work synergistically with thinner oils.

Yes. It's available in USA and Canada only. Same manual. PR25DD engine.

Here's the thing about that. The whole 0w-20 = bad idea started when the oil was specified as a quick hack to get mpg. Auto makers would simply change the spec on existing engines. In these cases I always opt for the heavier original spec.

With a clean slate design well into the 0w-20 era things have changed. There are certain design features that allow 0w-20 to perform well, as you yourself mentioned. I'll go further and say there are design features of modern mpg-focused engines that require 0w-20. I presented an example of this. One reason might not be enough, but it should at least be enough to warrant exploring the possibility. Should it not?

You actually presented an argument supporting this with your link about viscosity and bearing pressures. Clearances are reduced when designing for thinner to achieve the same protection. You never explained the hydrodynamic implications to film strength. I'm leaning toward inadequate lubrication with thicker oil. At least verification instead of assumption, something that should be a reasonable proposition to anyone.

I'll stick to the spec. Anything else is a "nebulous" endeavor of "better" oil.