Amsoil SS vs Z-ROD

[OVERKILL]

Amsoil SS 0w-30 with the high 8.8 NOACK, and 3.07 HTHS, as opposed to Z-ROD 10w-30 with 5.5 NOACK and 3.6 HTHS

The HTHS diff is because SS 0W-30 is an API oil, not Euro, so it has "typical" ILSAC/GF-6 HTHS. The SS 0W-40 would be more similar:
SAE 0W-40 FS Synthetic European Motor Oil | EFO - AMSOIL

They also make a 0W-30 Euro, but it is mid-SAPS, so has less phosphorous.

 

[OVERKILL]

Yes, so it would experience back pressure sooner with 10w oil than with 0w oil. Maybe milliseconds. All other things being equal (which they are not e.g. HTHS, NOACK, etc) 0w would be preferable to 10w in any climate. I get your reference over fretting over something that will not happen. In my climate(s) I'll never see much less than 30F, probably never see 20F. But even in warmer temps is there zero benefit of 0w over 10w? Or do the negative properties of 0w pose a higher risk that outweighs any benefit? I think I know the answer, but I'll still pose the question.

But the back pressure means nothing unless you are engaging the relief. A positive displacement pump, not on the relief, doesn't care if it's seeing 20psi or 50psi, it's still going to move the same amount of oil. You should read some of @ZeeOSix stuff on this subject.

 

[garageman402]

But the back pressure means nothing unless you are engaging the relief. A positive displacement pump, not on the relief, doesn't care if it's seeing 20psi or 50psi, it's still going to move the same amount of oil. You should read some of @ZeeOSix stuff on this subject.

I am familiar with Zee0Six, I have read his PD pump & filter writings. We have discussed when PD isn't PD anymore.

Let's say the main oil galley coming out of the pump is 1/4" diameter. There are smaller passages coming off of that, say some are 1/8", some are 1/16th. What I'm saying is the PD pump (in your extreme example, high pressure & high volume with extra thick oil (20w)) will fill the 1/4" galley quickly, but the smaller orifices are not getting oil yet, because until the oil fills that galley, its pressure is effectively zero. Full flow with zero resistance = zero pressure. So then it fills the 1/4" galley, & sees pressure, practically instantly, now the oil is attempting to get through the small orifices. Lets say the relief is set for 85psi, but the thick oil requires 90psi to get forced through the 1/16" galley. That galley will starve until it warms up enough to flow through with 85psi. If the galleys are full then the oil attempts to pass through the smaller passages instantly, pushing the relief open.

Extreme example but it illustrates my point that a thinner oil will circulate faster than a thicker oil. In real life with 10w-30 at 104F the difference is (very) small but still a difference nonetheless. The PD pump will force the oil through the small passages but the back pressure may be slightly higher with the 10w as opposed to the 0w. I agree if the relief is closed, the pump is pumping the same volume no matter what. But the 1/16" passages may be getting slightly less flow because the 1/8" passages are taking more of the flow. A thinner oil requiring less pressure to flow through those 1/16" passages will deliver more flow.

 

[OVERKILL]

I am familiar with Zee0Six, I have read his PD pump & filter writings. We have discussed when PD isn't PD anymore.

Let's say the main oil galley coming out of the pump is 1/4" diameter. There are smaller passages coming off of that, say some are 1/8", some are 1/16th. What I'm saying is the PD pump (in your extreme example, high pressure & high volume with extra thick oil (20w)) will fill the 1/4" galley quickly, but the smaller orifices are not getting oil yet, because until the oil fills that galley, its pressure is effectively zero. Full flow with zero resistance = zero pressure. So then it fills the 1/4" galley, & sees pressure, practically instantly, now the oil is attempting to get through the small orifices. Lets say the relief is set for 85psi, but the thick oil requires 90psi to get forced through the 1/16" galley. That galley will starve until it warms up enough to flow through with 85psi. If the galleys are full then the oil attempts to pass through the smaller passages instantly, pushing the relief open.

Extreme example but it illustrates my point that a thinner oil will circulate faster than a thicker oil. In real life with 10w-30 at 104F the difference is (very) small but still a difference nonetheless. The PD pump will force the oil through the small passages but the back pressure may be slightly higher with the 10w as opposed to the 0w. I agree if the relief is closed, the pump is pumping the same volume no matter what. But the 1/16" passages may be getting slightly less flow because the 1/8" passages are taking more of the flow. A thinner oil requiring less pressure to flow through those 1/16" passages will deliver more flow.

We are going in circles. That whole situation is predicated on the relief being active, which I've specifically stated like 30 times now. I'm out, have fun.

 

[kschachn]

I am familiar with Zee0Six, I have read his PD pump & filter writings. We have discussed when PD isn't PD anymore.

Let's say the main oil galley coming out of the pump is 1/4" diameter. There are smaller passages coming off of that, say some are 1/8", some are 1/16th. What I'm saying is the PD pump (in your extreme example, high pressure & high volume with extra thick oil (20w)) will fill the 1/4" galley quickly, but the smaller orifices are not getting oil yet, because until the oil fills that galley, its pressure is effectively zero. Full flow with zero resistance = zero pressure. So then it fills the 1/4" galley, & sees pressure, practically instantly, now the oil is attempting to get through the small orifices. Lets say the relief is set for 85psi, but the thick oil requires 90psi to get forced through the 1/16" galley. That galley will starve until it warms up enough to flow through with 85psi. If the galleys are full then the oil attempts to pass through the smaller passages instantly, pushing the relief open.

Extreme example but it illustrates my point that a thinner oil will circulate faster than a thicker oil. In real life with 10w-30 at 104F the difference is (very) small but still a difference nonetheless. The PD pump will force the oil through the small passages but the back pressure may be slightly higher with the 10w as opposed to the 0w. I agree if the relief is closed, the pump is pumping the same volume no matter what. But the 1/16" passages may be getting slightly less flow because the 1/8" passages are taking more of the flow. A thinner oil requiring less pressure to flow through those 1/16" passages will deliver more flow.

And honestly, why the obsession with flow? Flow never lubricates anything anyway.

You're cherry picking weird and unusual instances to illustrate a point that isn't significant.

 

[garageman402]

In Texas I would happily run 10w30, no way I would go 0w. I used 15w40 all summer in a 5.0 sbf, never a problem.

Actually, the SS 0w-30 has a higher 100C viscosity than the 5w-30, or the 10w-30, another reason I picked it, with no price difference.

But the Z-ROD 10w-30 does have higher a HTHS rating.

 

[garageman402]

We are going in circles. That whole situation is predicated on the relief being active, which I've specifically stated like 30 times now. I'm out, have fun.

My whole thin oil theory is based on AEHaas's writings, he is the one who said 30wt spec'd engines 'like' 10cSt oil, so to keep it as close to that as possible, hence my use of 0w-30. I was also recommended to use 0w-20 or 5w-20 in my 5w-30 spec'd engine with catastrophic results by a popular tribologist. His theory was "it's only 1cSt thinner, so should be no problem", & flow is important to deliver lubricant & take away heat.

Upon further reading, I am finding that the W ratings of oils just show pumpability at low temps. A 0w would have the same pumpability as a 10w at 40F, so really no need for the 0w in my climate. The "extreme" cases we both presented mean nothing at higher temps, so AEHaas's theory is not correct. @ZeeOSix posts indicate that with AW additives consistent across several grades of oil, more wear is attained with thinner grade oil, all else being the same.

See posts 54 & 60 here:

Thin vs Thick Discussion Midterm Examination

No oil is too thin on start up ?

bobistheoilguy.com

Thank you for patiently explaining this to me, I just ask followup questions instinctively.

 

[ZeeOSix]

I am familiar with Zee0Six, I have read his PD pump & filter writings. We have discussed when PD isn't PD anymore.

Let's say the main oil galley coming out of the pump is 1/4" diameter. There are smaller passages coming off of that, say some are 1/8", some are 1/16th. What I'm saying is the PD pump (in your extreme example, high pressure & high volume with extra thick oil (20w)) will fill the 1/4" galley quickly, but the smaller orifices are not getting oil yet, because until the oil fills that galley, its pressure is effectively zero. Full flow with zero resistance = zero pressure. So then it fills the 1/4" galley, & sees pressure, practically instantly, now the oil is attempting to get through the small orifices. Lets say the relief is set for 85psi, but the thick oil requires 90psi to get forced through the 1/16" galley. That galley will starve until it warms up enough to flow through with 85psi. If the galleys are full then the oil attempts to pass through the smaller passages instantly, pushing the relief open.

Extreme example but it illustrates my point that a thinner oil will circulate faster than a thicker oil. In real life with 10w-30 at 104F the difference is (very) small but still a difference nonetheless. The PD pump will force the oil through the small passages but the back pressure may be slightly higher with the 10w as opposed to the 0w. I agree if the relief is closed, the pump is pumping the same volume no matter what. But the 1/16" passages may be getting slightly less flow because the 1/8" passages are taking more of the flow. A thinner oil requiring less pressure to flow through those 1/16" passages will deliver more flow.

The only time the flow volume coming out of the PD pump is reduced is when the pump is in pressure relief. And even then, there is most likely plenty of flow volume capability still at the max relief pressure of the pump (say 80 to 100 PSI depending on the pump). The pump is going to force flow through all pressure fed passages of the oiling system, regardless of the size of the galleries. Keep in mind that if your oil filter's ADBV is working correctly, the oiling system should be retaining oil in most of, if not in all the oil galleries. So when an engine is fired up cold, oil should start flowing pretty quickly throughout the oiling system. The main concern in very cold start-ups is the W rating, and how well the oil flows to the pump pickup tube and also from the pickup to the pump. The W rating is all about cranking and pumpability of the oil at very cold conditions. Once it hits the pump, the pump will force the flow to the engine. And even if the pump hits pressure relief, the amount of flow it still pretty good for a cold start-up, lower RPM condition.

As @OVERKILL mentioned, do you know what the oil pump pressure relief is set to, and have you seen the oil pressure hit that relief pressure on a cold start-up without adding any additional RPM? It would have to be pretty cold and you'd have to be using a pretty high W rating for a PD pump to hit pressure relief at a low engine RPM.

 

[ZeeOSix]

Here's a chart from a study that measured oil pressure at the cam bearings (the last part of the system to become pressurized) with 10W-40 oil. With the oil at 20 C (around 300 cST), there is positive pressure at the cams within 2 seconds of when the engine starts cranking, and probably within a fraction of a second of the engine achieving idle speed.

Compare this to the test at -30 C, where the engine cranks for 15 seconds before firing up, takes another 17 seconds of idling to see any oil pressure at the cams, and then another 50 seconds of idling to see full oil pressure. Oil grade really matters in these extreme cold conditions, but there are diminishing returns as the oil gets thinner.

Is time zero the start of the engine cranking over, or the start of time after the engine fires up?

If the former, I think you are also seeing some pumpability factor of the oil to the pump becoming an increasing factor as the oil becomes colder and thicker, meaning the pumpability goes down (decreased flow rate into the pickup tube and to the pump inlet) which can mean the pump is not being fully enveloped as fast and takes longer to build pressure. Obviously, a PD pump puts out what it takes in if not in pressure relief, and if it's being "starved" to some degree during cranking then it's going to take longer to build oil pressure if it takes longer for the oil to flow into the pickup tube and pump inlet. The pump could also be hitting pressure relief as the temperature drops, thereby cutting back some volume to the oiling system, which would also cause the oil pressure to build more slowly once started.

 

[garageman402]

Upcoming 0W5 Grade Red Line Oil Experiment- 2019 Lincoln Navigator 4WD 3.5L V6 Twin Turbo

Engine: This Black Label version of the Navigator has a 3.5L, 450-hp twin-turbo V-6 pushing an over 3 ton barn door through the wind. It has 9k towing capacity and specs a 5W30 motor oil. It is mated to a 10-speed automatic transmission. The package gets you to 60 MPH in 5.4 seconds. Correct me...

bobistheoilguy.com

This is a very informative thread, especially the links to King Bearing, a lot of the participants are also here in my thread. Too bad it was shut down. 10 pages in 2 days, is that a record? Lol. We still didn't get the UOA from Dr. Haas.......

My questions were based around Dr. Haas' theory that thinner oil will circulate faster & remove heat. MOFT does play a major role, & that is missing in thinner oils. Apparently lower W numbers are meaningless in warmer conditions, which begs the question: Why are viscosity numbers given at 212F & 104F? I would think 75% of "cold starts" are between 25F & 60F, no one would consider 104F a "cold start". Yes, there are plenty of areas that are well below 25F, but I think the number of vehicles there is far lower than the number of vehicles in warmer climates.

So why do manufacturers specify 5w-30 even in warmer climates? Is fuel economy the only reason? E.g. a typical 10w-30 would protect better than a 5w-30 in moderate climates, due to higher HTHS & MOFT, but would produce slightly worse fuel economy?

My choice of 0w-30 over 5w-30 was based on the higher 100C vis than either the 5w or 10w-30 in Amsoil SS, the lower (slightly) 40C vis, & the price is the same. It does have higher NOACK, & lower HTHS, but still >2.9 which is spec'd for 30 oil.

I am going to go with the Z-ROD 10w-30 for my non-catalyst vehicles, but will probably stay with the 0w-30 for the other two, at least until I run out of stock. Would a Euro 0w-40 be a good substitute, given the higher HTHS? Or would the higher 100C vis negatively affect VVT operation?

Thanks!!

 

[ZeeOSix]

My questions were based around Dr. Haas' theory that thinner oil will circulate faster & remove heat. MOFT does play a major role, & that is missing in thinner oils.

Thinner oil circulates at the same speed as thicker oils because the same oil volume at X RPM is forced through the oiling system by the positive displacement oil pump - as long as the pump isn't in pressure relief. Oil pumps rarely go into pressure relief, it takes really thick oil and high RPM to get a PD into pressure relief - ie, if the engine is revved really high right after a cold start in the winter. The only time thinner oils flow faster is when they flow from gravity.

Apparently lower W numbers are meaningless in warmer conditions, which begs the question: Why are viscosity numbers given at 212F & 104F?

The W grade, and the KV40 and KV100 grades are two separate grade ratings, determined by different viscosity measurement methods/tests. KV40 and KV100 are used to calculate the oil viscosity index. Also, KV100 is basically the viscosity at the operating temperature (100C = 212F) of most engines.

 

[garageman402]

The W grade, and the KV40 and KV100 grades are two separate grade ratings, determined by different viscosity measurement methods/tests. KV40 and KV100 are used to calculate the oil viscosity index. Also, KV100 is basically the viscosity at the operating temperature (100C = 212F) of most engines.

So if the VI is calculated using those two points, then you would extrapolate to get a KV10 value? I don't think viscosity changes in a linear way. Is there a chart for W grade temperature ranges? E.g. 0w = -10 to +10, 5w = +5 to +20, etc? I just threw random numbers in there for examples.

What is the reason 40C & 100C were used? 100C is obvious, the usual operating temp, but I would think a lower temperature value would be more useful in the real world. As I mentioned earlier, I would not consider 40C a "cold start", seems like 10C or 20C would be more appropriate for cold starts.

Thinner oil circulates at the same speed as thicker oils because the same oil volume at X RPM is forced through the oiling system by the positive displacement oil pump - as long as the pump isn't in pressure relief. Oil pumps rarely go into pressure relief, it takes really thick oil and high RPM to get a PD into pressure relief - ie, if the engine is revved really high right after a cold start in the winter. The only time thinner oils flow faster is when they flow from gravity.

So why would engine manufacturers specify a 5w-30 instead of a 5w-40 or 5w-50 if they all circulate at the same speed (as long as they are pump-able)? Is it because of bearing clearance? HTHS?

At +5C (a chilly morning) pretty much any grade oil is pump-able, so it wouldn't make any difference if a 0w-30 was used or a straight 30 or 40 was used? I would assume a thicker oil would have more MOFT, so the start-up wear would be mitigated by residual oil?

 

[56Cummins]

I like what you are saying, a rating at 32°F would be nice for comparisons.

 

[ZeeOSix]

So if the VI is calculated using those two points, then you would extrapolate to get a KV10 value? I don't think viscosity changes in a linear way.

Use this tool to see how oil viscosity changes with temperature.

Graph your oils | Widman International SRL

www.widman.biz

Is there a chart for W grade temperature ranges? E.g. 0w = -10 to +10, 5w = +5 to +20, etc? I just threw random numbers in there for examples.

SAE J300 defines the W grades. I added the C to F info at the bottom for my use. This J300 chart has been posted 100s of times on BITOG.

What is the reason 40C & 100C were used? 100C is obvious, the usual operating temp, but I would think a lower temperature value would be more useful in the real world. As I mentioned earlier, I would not consider 40C a "cold start", seems like 10C or 20C would be more appropriate for cold starts.

I don't recall exactly why 40C is used ... it's buried someplace on my computer, lol. Here's the way the viscosity index is calculated using the oil viscosity at 40C and 100C. Along with some other general info about the viscosity index.

This article has lots of VI info. At some point early on, 40C and 100C became standard temperatures to measure viscosity at.

The Ultimate Guide to Engine Oil Viscosity - Best Synthetic Oil Guide

A package of automotive engine oil bears combinations of letters and figures and you are thinking what the heck is SAE 5W-20 or 5W-30? Find out here.

bestsyntheticoilguide.com

So why would engine manufacturers specify a 5w-30 instead of a 5w-40 or 5w-50 if they all circulate at the same speed (as long as they are pump-able)? Is it because of bearing clearance? HTHS?

The KV100 is not about circulation. There's a reason why positive displacement oil pumps are used on engine oiling systems ... because it ensures the same volumetric flow per RPM pretty much regardless of the oil viscosity. Of course, in some extreme conditions the PD pump can go into pressure relief, but most pumps are not in pressure relief 99% of the time. Yes, oil with higher KV100 is typically specified for more engine protection, and of course everyone should know by now that lower KV100 oils are mainly specified to try and achieve better fuel economy while still giving "adequate" (not "maximum) engine protection. Again a subject that has been discussed 1000s of time ... ie, "thick vs thin" type discussions.

At +5C (a chilly morning) pretty much any grade oil is pump-able, so it wouldn't make any difference if a 0w-30 was used or a straight 30 or 40 was used? I would assume a thicker oil would have more MOFT, so the start-up wear would be mitigated by residual oil?

No matter what the W grade is, the oil is always thicker on a cold startup than it is at operating temperature. So there's really no worries about adequate MOFT with cold oil. For cold starts, it's all about the W grade (why the W grade SAE J300 rating was invented), and people who live in very cold climates need to use the right W grade for the coldest startup conditions. But yes, if it doesn't get that cold, then the W grade won't matter too much. But in some extreme cold parts of the country the W grade can become very important.