Confessions of a Recovering Thickie

[ZeeOSix]

And again. The coatings work synergistically with thinner oils. You're cherry picking within the cherry pick, if you will.

No coating is going to remove the benefits of more MOFT. The coating is there because the thinner oil has less MOFT and they need the coating to mitigate wear from lack of film thickness.

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

Here ya go ... the same PR25DD engine in the European 2023 Nissan X-Trail (same as the Rouge). Mind blowing ... she's going to blow-up with that xW-50. You can find the OM easy with some Googling.

Here's the thing about that. The whole 0w-20 = bad thing 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.

Yes they did, thinking they could sacrifice some added engine wear for more fuel economy and CAFE credits. But again, some like Ford have recently gone back up a grade, for obvious reasons.

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.

Yeah, probably some "design features" even on xW-20 speced engines ... but still doesn't mean there isn't some added protection with a grade or two higher. Why do you think that Nissan OM shows all those oil viscosities in the OM when the EPA/CAFE are out of the loop.

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.

No bearing is designed to have reduced clearances to "achieve the same protection". Regardless of the bearing clearance, higher viscosity gives benefits, and the temp rise is a non-issue as shown previously. There is no "hydrodynamic implication to film strength". Did you read that Machine Lubrication article in the other thread? When the MOFT goes to zero between any two moving parts, it's only the oil film strength that reduces wear from rubbing. So the hydrodynamic wedge MOFT in a journal bearing would also have to go to zero (from lack of viscosity) for the film strength to kick-in. You might want to do some research on how journal bearings really work because it seems you've got some misconceptions going on.

I'm leaning toward inadequate lubrication with thicker oil. At least verification instead of assumption, something that should be a reasonable proposition to anyone.

There is no "inadequate lubrication with thicker oil" in journal bearings. Again, the example of the Ford Coyote and even the Nissan X-Trail using a wide range of viscosity. You think Nissan would put that oil viscosity chart in the OM if thicker oil caused "lack of lubrication" or any kind of engine damage. Pretty simple logic to conclude they know it doesn't cause any "lack of lubrication" or engine harm. Instead, they know a thicker oil gives more engine protection when the ambient temps are higher which causes the oil to run a bit hotter.

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

Yeah, you probably should ... don't want the "warranty boogie man" to get ya, lol. This is just going in circles now - Mods should probably just lock it.

 

[chris719]

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.

There are people with tens of thousands of track miles running 5W-50 in BMW B58 engines (with sputter coated bearings) that come with 0W-20 from factory in TU2 guise. Nothing happens except wear goes down. Redbull Driftbrothers run 300V 10W-60 and BMW M tore down their stock engine and it looked perfect. That engine (S58) specifies 0W-30 3.0 HTHS in US. It is full of advanced coatings yet somehow it’s running 10W-60 in a BMW Motorsport sanctioned program hmm.

Could be that you just don’t know anything and everything you say is 100% logical fallacy - argument to authority.

 

[siriusc1024]

No coating is going to remove the benefits of more MOFT. The coating is there because the thinner oil has less MOFT and they need the coating to mitigate wear from lack of film thickness.


Here ya go ... the same PR25DD engine in the European 2023 Nissan X-Trail (same as the Rouge). Mind blowing ... she's going to blow-up with that xW-50. You can find the OM easy with some Googling.

View attachment 280721


Yes they did, thinking they could sacrifice some added engine wear for more fuel economy and CAFE credits. But again, some like Ford have recently gone back up a grade, for obvious reasons.


Yeah, probably some "design features" even on xW-20 speced engines ... but still doesn't mean there isn't some added protection with a grade or two higher. Why do you think that Nissan OM shows all those oil viscosities in the OM when the EPA/CAFE are out of the loop.


No bearing is designed to have reduced clearances to "achieve the same protection". Regardless of the bearing clearance, higher viscosity gives benefits, and the temp rise is a non-issue as shown previously. There is no "hydrodynamic implication to film strength". Did you read that Machine Lubrication article in the other thread? When the MOFT goes to zero between any two moving parts, it's only the oil film strength that reduces wear from rubbing. So the hydrodynamic wedge MOFT in a journal bearing would also have to go to zero (from lack of viscosity) for the film strength to kick-in. You might want to do some research on how journal bearings really work because it seems you've got some misconceptions going on.


There is no "inadequate lubrication with thicker oil" in journal bearings. Again, the example of the Ford Coyote and even the Nissan X-Trail using a wide range of viscosity. You think Nissan would put that oil viscosity chart in the OM if thicker oil caused "lack of lubrication" or any kind of engine damage. Pretty simple logic to conclude they know it doesn't cause any "lack of lubrication" or engine harm. Instead, they know a thicker oil gives more engine protection when the ambient temps are higher which causes the oil to run a bit hotter.


Yeah, you probably should ... don't want the "warranty boogie man" to get ya, lol. This is just going in circles now - Mods should probably just lock it.

Hold on. Give me a link to that manual. I got one online. It's for 2014 and shows the older QR25DE, which was released in 2000.

I think we're looking at the same manual. The page below this shows that same graphic with the same STI0732.
https://www.nissan.co.th/content/dam/Nissan/th/owners/OwnerManual-170612/X-Trail Owner Manual EN.pdf

 

[siriusc1024]

There are people with tens of thousands of track miles running 5W-50 in BMW B58 engines (with sputter coated bearings) that come with 0W-20 from factory in TU2 guise. Nothing happens except wear goes down. Redbull Driftbrothers run 300V 10W-60 and BMW M tore down their stock engine and it looked perfect. That engine (S58) specifies 0W-30 3.0 HTHS in US. It is full of advanced coatings yet somehow it’s running 10W-60 in a BMW Motorsport sanctioned program hmm.

Could be that you just don’t know anything and everything you say is 100% logical fallacy - argument to authority.

10w-60 in the Rogue?

 

[ZeeOSix]

Hold on. Give me a link to that manual. I got one online. It's for 2014 and shows the older QR25DE, which was released in 2000.

2023 X-Trail with the PR25DD ----> LINK

 

[siriusc1024]

Ah found it. 2024 X-trail UK shows what you posted.
https://www.nissan.co.uk/owners/car...xtrail/0t33/e1/2024/petrol-engine-oil-1.shtml

Well. 0w-20 preferable in the UK and satisfactory in the US.

Seems this engine doesn't care. Giving more consideration to going with the 5w-30 when it's out of warranty, which is soon.

 

[ZeeOSix]

Seems this engine doesn't care.

Engines don't care about using a higher KV100 grade, and more viscosity gives added engine protection - lots of test data shows that, and many OMs outside the US for the same engines like shown above with a wide range of recommended viscosity. Engines can care about the "W" grade if the wrong grade is used in the wrong ambient environment and the oil is too thick to pump and flow effectively - there have been lots of threads about the W grade, and pumpability and flow. Maybe the light bulb has came on now.

 

[siriusc1024]

Engines don't care about the KV100 grade, and more viscosity gives added engine protection - lots of test data shows that, and many OMs outside the US for the same engines like shown above with a wide range of recommended viscosity. Engines can care about the "W" grade if the wrong grade is used in the wrong ambient environment and the oil is too thick to pump and flow effectively - there have been lots of threads about the W grade, and pumpability and flow. Maybe the light bulb has came on now.

Within reason. I'm not considering going up to -40. I was mostly concerned with the specific requirements of the engine for selecting viscosity. I don't think a -40 will help more than a -30 here. Part of me takes those overseas recommendations as use what you've got. Unlike the US manual, that manual doesn't even specify GL-6 or anything. It basically says use some oil and looks like something out of a lawnmower manual. Grain of salt.

I think Glenda W.'s recommendation of 0w-30 ESP is about right. This engine has a cooled EGR, and that's eventually going to need cleaned out. I'd like to avoid doing that repair. ESP is emissions system protection. 5qt was on sale a couple days ago when I picked up the QS. ESP in the Rogue next. See how it does.

 

[ZeeOSix]

Within reason. I'm not considering going up to -40. I was mostly concerned with the specific requirements of the engine for selecting viscosity. I don't think a -40 will help more than a -30 here. Part of me takes those overseas recommendations as use what you've got. Unlike the US manual, that manual doesn't even specify GL-6 or anything. It basically says use some oil and looks like something out of a lawnmower manual. Grain of salt.

Yes, within reason ... but as the Nissan OM shows, any of those viscosities can be used, they are all recommended so it's up to the owner to decide. Another data point that says engines are not sensitive to the KV100 viscosity. Like said earlier, going up a grade on anything that specs a xW-20 or less is going to give some added protection. If the vehicle is planned to really be used hard, like for track use then going up two grades would be beneficial.

I think Glenda W.'s recommendation of 0w-30 ESP is about right. This engine has a cooled EGR, and that's eventually going to need cleaned out. I'd like to avoid doing that repair. ESP is emissions system protection. 5qt was on sale a couple days ago when I picked up the QS. ESP in the Rogue next. See how it does.

The 0W-30 gives both the good W rating and decent KV100 viscosity. Should work well in anything specifying a xW-20 or xW-30.

 

[Glenda W.]

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?

This is a new test separate from my oil burner test. Full results by the end of the year with pics. The vehicle is on its second oci of ESP and clean up is occurring. It’s in a friends short tripped Forester with heavy buildup in the timing chain and oil fill areas.

 

[Glenda W.]

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. I already commented on my experience with FS in a previous post. I honestly think M1 oils start out great but wear down quickly. I think the base stock sucks and they compensate with additives. That's just my opinion.

Right now I use QS Synthetic 5w-30 in the LS, QS Synthetic 0w-20 in the Rogue. 5k OCI on both. M1 filters.

As far as cleanliness with Dex lemme show ya. I just walked out and snapped this for you. This is my head bolt. I put a dash on the head bolts with permanent marker for degree torque. Rocker on the left (hint of bronze if you look closely by the snap ring). Bright aluminum casting in the head. I did the head swap 80k ago.


View attachment 280687

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. I've already expressed how important it is to make consideration for the engine architecture when deviating from spec. I can't find enough information to make a good informed decision. Especially, now that I know about the existence of piston ring coatings commonly found in mpg-focused engines, I'm leery of going thicker. I'll stick to the spec.

The basic Mobil 1 may not have the best base oil(honestly not sure) but the ESP line uses a GTL/PAO/Ester base(except ESP 5w30).

Your engine appears clean! Although my Outback was spotless, but had stuck oil control rings.

 

[siriusc1024]

The basic Mobil 1 may not have the best base oil(honestly not sure) but the ESP line uses a GTL/PAO/Ester base(except ESP 5w30).

Your engine appears clean! Although my Outback was spotless, but had stuck oil control rings.

Sounds excellent. The one time I went 5w-30 in the Nissan was Pennzoil Platinum because GTL and because I was worried about the low tension rings.

Good to know ESP 5w-30 is different.

 

[kschachn]

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.

Ahh yes I was waiting for this. The whole argument follows what is a predictable pattern, that somehow thinner oils are better, then that they are required for some particular aspect of engine operation. Then when that is shown to be patently false, the next assertion is that it is a warranty requirement. You're doing great here by hitting all the erroneous falsehoods.

You're not going to cause engine damage with an oil that has a higher HT/HS. That is false and ignorant of basic physics. Yes, a wrong viscosity that is too thin can and may very well cause damage and that's what the owner's manual means.

 

[kschachn]

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.

Synergistically with thinner oils? What on earth does that mean? What they do is allow engine operation with thinner oils without causing excessive wear. There is no synergy with the oil, they work just the same way with a thicker oil. This is dream land stuff you're stating.

No engine requires a specific grade. That's a gross misstatement based on gross misunderstanding. Another clue is that you continue to include the winter rating in your argument. That has zero to do with the operational viscosity where the majority of wear occurs. As much as no engine is designed to require a -20 grade it even more surely does not require a specific winter rating. That is entirely dependent on starting temperature.

 

[hemioiler]

@siriusc1024

Viscosity is not a single value, it changes with temperature. In other words, a 20W oil at 10C is far thicker than a 30W at 90C. In order for them to deny warranty they'd have to prove that your engine.... can survive a thinner grade at cold temps but not a thicker grade at hot temps when it's actually thinner? I'd say a judge is capable of following a simple chart:

 

[Glenda W.]

@siriusc1024

Viscosity is not a single value, it changes with temperature. In other words, a 20W oil at 10C is far thicker than a 30W at 90C. In order for them to deny warranty they'd have to prove that your engine.... can survive a thinner grade at cold temps but not a thicker grade at hot temps when it's actually thinner? I'd say a judge is capable of following a simple chart:


View attachment 280744

100%. As I pointed out earlier, understanding oil temperature is key. Engines cannot be viscosity sensitive. Our friends in the north would be in serious trouble. Oil temperature is also key in choosing the correct viscosity for use case.

 

[KEVINK0000]

I consider myself a thickie, when I feel it’s warranted. (20-50 in rotary, air cooled bikes,etc)
If you consider all engines, and add them together, I marvel at the fact that more horsepower is produced currently, with oils thinner than ever before.

 

[chris719]

10w-60 in the Rogue?

You could without harm I bet, yes. Not that you should.

 

[OVERKILL]

I specifically mentioned parts that don't have a pressurized oil supply. That's many. I know you might not be familiar with engines, but that doesn't excuse the profoundly terrible reading comprehension.

So how does that work with cold oil? Are these engines when operated in Winnipeg or Alaska just failing constantly because parts that are not pressure lubed are starved?

As I pointed out in a previous discussion, engines CANNOT be as sensitive to viscosity as some claim, because ambient conditions have a far greater impact on viscosity than the grade on the bottle. As Zee has noted, it's the Winter grade that's really the important aspect, making sure the oil will actually make its way up the pick-up and into the pump.

 

[chris719]

I think Glenda W.'s recommendation of 0w-30 ESP is about right. This engine has a cooled EGR, and that's eventually going to need cleaned out. I'd like to avoid doing that repair. ESP is emissions system protection. 5qt was on sale a couple days ago when I picked up the QS. ESP in the Rogue next. See how it does.

If you can run a Euro 3.5 HTHS 30 you can run a Euro 40 also. The HTHS is just about the same and so the dynamic viscosity is. Not saying you need to but there’s not much daylight between them.