Something to consider when the oil change topic happens here

[UnleashedBeast]

Another thing to point out is that all drivers and track days are not the same. I drive my car in the upper RPM range and manage my shifts to keep the RPMs 5k-7200 ALL THE TIME. That takes some practice.
An HPDE 1-2 driver is not going to do that, so that will have an effect on the outcome. I just don't want to hear some HPDE 1 Boss driver come back and say the non-standard, unrecommended oil WORKS FINE on track. Because its a ticking time bomb.
Any smart Boss track driver won't be doing this, so we likely won't have good data points.

And I've decided to send my oil out for analysis after the recommended FOUR HOURS of track use (high RPM track use). I will post the findings here.

Ticking time bomb? You use Motorcraft 5W-50, yet call any true synthetic 10W-40 use on the track a ticking tomb bomb?

Post up your UOA after 4 hours of high RPM track use, let's see how rapidly it sheared. I'd love to see it.

Question, if it shears to a 40 grade lubricant within your testing parameters, what does that mean to you?

Sorry, but i'm not following you on this. The oil that's recommended doesn't impact the cost of producing the car (ok, it does, but very minimally), so why would the bean counters care? If we take it one step further, if the oil recommended wasn't good enough to sustain the car (including some track use....since that's what the car was designed for), they might also face higher costs for warranty claims....aka engine failures. No?

Or perhaps the oil is just good enough to get through the warranty period....and then they can reap the benefit of having more $$ generated through engine repairs the owners have to pay for? <----Have a hard time believing Ford would take this approach with the Boss.

I'll take my chances with the Mobil 1 5W-50.

To clarify, engineers do not always get final word in a decision process. For example, a reliability testing engineer with the 4.6L 3 valve engine, after 100 tear down tests, noticed Motorcraft 5W-30 was performing better in the engine than Motorcraft 5W-20. Wear was reduced. However, the bean counters feared fines from the Federal Government for CAFE laws, deciding on the 5W-20 recommendation anyway. Why you ask, because 5W-20 still allowed this engine to perform far outside the warranty period and the slight increase in fuel economy would reduce CAFE fines. This is not saying that a premium 5W-20 lubricant in a grocery getting grandma driving Mustang would not achieve 300k+ miles. It's simply more towards the performance junkie. This engineer recommended Ford stick with the Motorcraft 5W-30 requirement, or equivalent. Upper management didn't agree.

That doesn't make any sense at all. I understand in your data that the MC shears rapidly. Are you saying if you change the MC 5w50 per the manual for track use that HT/HS doesn't matter?

Er...not sure where you're getting that data, but pretty sure that's not quite right either. The specific heat of oil is not different with different viscosities. Perhaps you mean to say they generate less heat?

And are you saying that less viscous lubricants have a higher average viscosity in extreme conditions? Is that a typo?

No, I simply meant that the lubricant would likely shear outside of the grade during the first or second weekend of use. HT/HS would no longer be in the 4.9-5.0 range a 50 grade lubricant provides. True synthetic 10W-40 lubricants hold in the 4.3 range. 30 grade lubricants drop to the 2.9-3.1 range. Motorcraft 5W-50 HT/HS is estimate to be in the 3.5 range after 1,500 miles of use. cSt @ 100*C averages in the 13.x range after this many miles.

Also, a lighter lubricant releases heat more rapidly than a more viscous lubricant. This will REDUCE your oil sump temps, therefore allowing the less viscous lubricant to maintain a higher HT/HS rating on average than a more viscous lubricant. In easy terms, Amsoil 10W-40 would maintain it's HT/HS raiting at the high end of it's average. The more viscous Motorcraft 5W-50 would maintain it's rating at the lower end of its average. This would allow their HT/HS ratings to be closer than what actually shows on the specification sheet.

I still don't get why you've recommended the 10W-40 in the past to anybody even doing one track day. I've seen a handful of Boss guys say they're running the 10W-40 after reading your threads and were planning on doing from one to a few track days. Since I haven't seen a UOA from a Boss using 10W-40 and *any* track miles I've been a little concerned for those guys.

Most Boss track owners are terrified of doing anything other than what Ford says, despite science. I've chatted with racing experts before, and their knowledge is vast.....right up until you try to discuss lubrication technology. The extent of their knowledge is....."I use this because XYZ said I have too." or "I use this because it's what I am sponsored with."

IIRC, just the bearings, rod bolts and maybe a couple other things. While almost everything will cross-bolt between the two, they are more different than alike.

Bingo, bearing clearances. Translation, on the street....5W-50 is NOT required. You can use Ford's recommended 5W-20 if you wanted too, since the high levels of heat common on closed course will not be present. All local Boss 302 cars in my area, street use only, are rocking Amsoil ATM 10W-30. The engine starts easier, get's better efficiency & power output, and wear decreased.

and to all those who think "Automotive company engineers know best, I always listen to them first". Do you really think they are always right and have the best solution for a design? If that were the case, this would not be happening to the 5th generation Camaro. Sometimes, they have to work with what they have, not what they wanted or asked for. (i.e. Motorcraft 5W-50)

Video and article link

 

[UnleashedBeast]

Within the past 6 months, I've shifted my choice of Amsoil 10W-40 lubricant. Now, I'm more attracted to Amsoil's newer XLO 10W-40, for a few reasons.

API SN levels of ZDDP with boosted Moly and Boron to compensate
Friction modifiers in the formulation, further reducing friction and heat, increasing efficiency
Higher viscosity at 100*C than Amsoil AMO 10W-40
NOACK only slight higher than AMO, however still much lower than any off the shelf lubricant

It doesn't have as much TBN or the duration of change interval, but will still easily achieve 10,000 miles in an 8.5 quart sump. The additive package in XLO is far more important to me than rock solid base oil in AMO.

 

[Grant808]

No, I simply meant that the lubricant would likely shear outside of the grade during the first or second weekend of use. HT/HS would no longer be in the 4.9-5.0 range a 50 grade lubricant provides. True synthetic 10W-40 lubricants hold in the 4.3 range. 30 grade lubricants drop to the 2.9-3.1 range. Motorcraft 5W-50 HT/HS is estimate to be in the 3.5 range after 1,500 miles of use. cSt @ 100*C averages in the 13.x range after this many miles.

Actually, your estimate of HT/HS properties is unfounded. The change in cSt @ 100C does not imply or relate to change in performance in HT/HS which is at 150C. Depends on the chemistry of the base stock, right?

My issue with you recommending a 10w40 for track use is that it never starts with a high HT/HS spec. Most track rats change their oil frequently enough that even rapid shear should not be an issue. One of the things I noticed that concerns me are the Lead and Iron wear from the few 10w40 samples you do have on your spreadsheet for the Boss engines. You don't have notes on the specific car/engine use posted like you do on the GT500 sheet, so I'm not sure how these cars are used. I'm most concerned that they are showing this wear if they are only used on the street.

Also, a lighter lubricant releases heat more rapidly than a more viscous lubricant. This will REDUCE your oil sump temps, therefore allowing the less viscous lubricant to maintain a higher HT/HS rating on average than a more viscous lubricant. In easy terms, Amsoil 10W-40 would maintain it's HT/HS raiting at the high end of it's average. The more viscous Motorcraft 5W-50 would maintain it's rating at the lower end of its average. This would allow their HT/HS ratings to be closer than what actually shows on the specification sheet.

No, as I said above...viscosity does not affect the specific heat of oil. Please go read up on this. I believe you are misinterpreting something you must have read.

Most Boss track owners are terrified of doing anything other than what Ford says, despite science. I've chatted with racing experts before, and their knowledge is vast.....right up until you try to discuss lubrication technology. The extent of their knowledge is....."I use this because XYZ said I have too." or "I use this because it's what I am sponsored with."

I think that's just plain false. Boss/track owners seem to be the most concerned over performance and longevity over most other mustang owner groups, regardless of warrantee issues. Ford has also proved to be *exemplary* in standing behind Bosses used on the track. I think we're the group that operates with the LEAST amount of fear about warrantee issues.

I agree that chatting with 'racing experts' doesn't make them experts on these engines or lubrication.

Bingo, bearing clearances. Translation, on the street....5W-50 is NOT required. You can use Ford's recommended 5W-20 if you wanted too, since the high levels of heat common on closed course will not be present. All local Boss 302 cars in my area, street use only, are rocking Amsoil ATM 10W-30. The engine starts easier, get's better efficiency & power output, and wear decreased.

I never disagreed about use of lighter weights on street/commuter cars. Would be nice to see some 10w30 UOA from your local Bosses, though. My only issue and concern here is with your track recommendation of 10w40. Still not sure why you'd stick with that recommendation despite the lack of data.

And if you could, please fix the quotes above, you've got a lot of what I said quoted as Race Red Boss'.

 

[UnleashedBeast]

You believe that a base oil with a 30 grade viscosity @ 100*C will maintain a high HT/HS like found in a 50 grade viscosity? In other words, you are saying that a lubricant which shears from a 50 grade down to a 30 grade will still have a HT/HS of a 50 grade lubricant, not a 30 grade?

The high lead and iron you see were from track cars. Let's see a sample of Motorcraft 5W-50 after two weekends of track sessions and some street highway miles/street racing. You'd come to respect the difference. I'd ask Darren to give us a sample beyond the 4 hours he intends to provide, but I'm assuming he would decline.

Again, today I lean towards Amsoil's newer XLO formulation for the reasons mentioned prior. AMO is dated, ready to retire.

 

[Grant808]

You believe that a base oil with a 30 grade viscosity @ 100*C will maintain a high HT/HS like found in a 50 grade viscosity?

No.

In other words, you are saying that a lubricant which shears from a 50 grade down to a 30 grade will still have a HT/HS of a 50 grade lubricant, not a 30 grade?

No, I don't know and can't know because it would depend on the samples and the actual HT/HS test results. What I am saying is that you don't know either. First, there is a big difference in the definition of SAE grades and the HT/HS spec. Second, one is more like a test of flow under pressure, and the other is more like the conditions in a crank bearing. The two properties don't need to change in lock-step.

The high lead and iron you see were from track cars. Let's see a sample of Motorcraft 5W-50 after two weekends of track sessions and some street highway miles/street racing. You'd come to respect the difference. I'd ask Darren to give us a sample beyond the 4 hours he intends to provide, but I'm assuming he would decline.

From the road runners too or just the rebuilt GT500s? I'm all for more data. If you know of a lab that does HT/HS on used oil please post that up...I haven't found one.

I'd decline testing beyond 4 hours of track time myself. I don't really see the point. Penny pinching to run oil longer doesn't make sense when compared to the rest of the expenses from real track use.

 

[darreng505]

Some additional thoughts (not a direct response to your previous post Grant).

And part of the issue about oils is not just weight but also specification. The motorcraft 5w50 meets Fords M2C913-B spec. other 5w50 oils like Castrol is only M2C913-A. Some light research turns up that these specifications include properties such as "performance for anti-wear, deposit protection and oxidation stability"

There are many reasons one oil differs from another, even with the same weight. It's not just about shear. All oils will shear and they are designed to be swapped well within the performance zone. The additional properties of Ford recommended oils are important with respect to the motor qualities and intended use.

Playing this game that "you can get away with a lesser or different oil spec" because "you only go get groceries" or "my friend did it and it's ok" is just stupid. You could get away using baby oil in your motor to go get groceries (1 mile radius lol)...so its a really lame point to keep repeating.

And in terms of cost, you're gonna pay either way. Down the road when you have engine issues or up front for the quality oil.

------

Penny pinching to run oil longer doesn't make sense when compared to the rest of the expenses from real track use.

Agree 100%. Because why bother risking engine damage to save $50 in oil when your consumables are $1500 already? Faulty logic. That's one of the lines of reasoning I've been battling in these threads....:mj:

 

[UnleashedBeast]

No, I don't know and can't know because it would depend on the samples and the actual HT/HS test results. What I am saying is that you don't know either. First, there is a big difference in the definition of SAE grades and the HT/HS spec. Second, one is more like a test of flow under pressure, and the other is more like the conditions in a crank bearing. The two properties don't need to change in lock-step.

You've said enough. This post alone tells me how little you actually understand about lubrication technology. There is no need for me to entertain your trolling and lack of understanding any longer in this thread.

SAE grade is determined by a few different tests.

Viscosity @ 100*C and cold pour viscosity to name the two major factors.

High Temp / High Shear is the viscosity of a lubricant @ 150*C (i.e. the viscosity of a lubricant in the hottest part of the engine, around the pistons)

If you think there is no relationship of comparison between the two, then you really haven't a clue. Do us all a favor, go back to the track, drive your car for four hours, and change your oil. You obviously love to waste money as "cheap insurance". With a comment like the one you made above, I wouldn't expect you to understand anyway.

Some additional thoughts (not a direct response to your previous post Grant).

And part of the issue about oils is not just weight but also specification. The motorcraft 5w50 meets Fords M2C913-B spec. other 5w50 oils like Castrol is only M2C913-A. Some light research turns up that these specifications include properties such as "performance for anti-wear, deposit protection and oxidation stability"

There are many reasons one oil differs from another, even with the same weight. It's not just about shear. All oils will shear and they are designed to be swapped well within the performance zone. The additional properties of Ford recommended oils are important with respect to the motor qualities and intended use.

Playing this game that "you can get away with a lesser or different oil spec" because "you only go get groceries" or "my friend did it and it's ok" is just stupid. You could get away using baby oil in your motor to go get groceries (1 mile radius lol)...so its a really lame point to keep repeating.

And in terms of cost, you're gonna pay either way. Down the road when you have engine issues or up front for the quality oil.

Why do you think I prefer Amsoil XLO 10W-40 over AMO 10W-40? I prefer the additive package in XLO over AMO, despite the base oil being a blend of true synthetic and group III hydrocracked petroleum.

Agree 100%. Because why bother risking engine damage to save $50 in oil when your consumables are $1500 already? Faulty logic. That's one of the lines of reasoning I've been battling in these threads....:mj:

Already been proven by a UOA in another thread. 8,200 miles on his oil change, with 1.5 hours of road course driving......other than shearing, the lubricant was good for continued use. You and Grant should go play together, it would make good company.

 

[Grant808]

You've said enough. This post alone tells me how little you actually understand about lubrication technology. There is no need for me to entertain your trolling and lack of understanding any longer in this thread.

SAE grade is determined by a few different tests.

Viscosity @ 100*C and cold pour viscosity to name the two major factors.

High Temp / High Shear is the viscosity of a lubricant @ 150*C (i.e. the viscosity of a lubricant in the hottest part of the engine, around the pistons)

If you think there is no relationship of comparison between the two, then you really haven't a clue. Do us all a favor, go back to the track, drive your car for four hours, and change your oil. You obviously love to waste money as "cheap insurance". With a comment like the one you made above, I wouldn't expect you to understand anyway.

This would be the perfect internets-straw-man-takedown, except that you apparently don't even grasp the differences in units of the two viscosity specs we've been discussing. And I think people viewing this thread are smart enough to see that you don't know everything and that you're not even answering my questions. If I were totally off the mark, I think the SVTP community would have basically said so.

The SAE grading in cSt are not the same units or type of units as cP for HT/HS. They are not even tested in the same manner or on the same type of testing equipment. It's not just for the difference in temperature. HT/HS simulates the conditions of hot oil in the bearings, not the pistons as you mention above. And that's why per ASTM specs it's tested on a 'tapered bearing simulator'. Seriously, I've done very little research on this, but can clearly see that you don't really understand what these specs *actually* mean.



But back to your straw man argument...

* You haven't proven how you've 'tested' 10w-40 to be good for the roadrunners aside from running it around on your GT or GT500 and checking the pressure gauge.

* You've stated many times that you think 50 grade oils are too heavy for Roadrunners, yet you don't have any proof of those claims.

* You have not provided any UOAs of your local Boss buddies using 10W-30 Amsoil for the street.

* I can only hope you now understand the functional differences between the Boss/Coyote/GT500 and why their oil requirements may be different even for the same driving use. And mainly the point that the Boss is functional to 7,500 or up to 8,200 RPM for aftermarket tunes.

* You've successfully made fun of me for changing my oil too soon. Congrats.



My apologies for getting your pants up in a bunch, but the ONLY reason I started posting in this thread after following it quietly from the beginning is the handful of Boss owners who said they were running Amsoil 10W-40 and were planning on some track time based on reading this thread. It got me curious enough to ask some questions, and now I definitely have them answered.

 

[UnleashedBeast]

Doesn't matter if you measure it in meter, inches, peanuts, acorns, or miles.....

There is a direct relationship between Viscosity in cSt and HT/HS in cP. When one reduces in viscosity, so does the other. You seem to deny this fact, or this fact doesn't conform to your agenda here.

Please continue to use what lubricant makes you feel good inside, that's what people do. You've answered no questions in this thread what-so-ever, only made quick conclusions that favor your point of view without trends to justify them. This conversation is concluded, and is no longer deemed productive to this thread. Besides, your use of the Boss 302 Roadrunner likely accounts for less than 1% of the percentile in this forum. Most people who own this car drive them on the street. I will no longer reply to any comments made by yourself or Darren in this thread.

 

[darreng505]

Doesn't matter if you measure it in meter, inches, peanuts, acorns, or miles.....

There is a direct relationship between Viscosity in cSt and HT/HS in cP. When one reduces in viscosity, so does the other. You seem to deny this fact, or this fact doesn't conform to your agenda here.

Please continue to use what lubricant makes you feel good inside, that's what people do. You've answered no questions in this thread what-so-ever, only made quick conclusions that favor your point of view without trends to justify them. This conversation is concluded, and is no longer deemed productive to this thread. Besides, your use of the Boss 302 Roadrunner likely accounts for less than 1% of the percentile in this forum. Most people who own this car drive them on the street. I will no longer reply to any comments made by yourself or Darren in this thread.

So now you're a spokesperson for a car you don't even own and you're just picking random statistics to support your point?? LMAO. You just tried to rail on Grant for that same thing, then turn around and do what you've been doing, which is pluck some unverified information, pass it as fact, and tell everyone else they're stupid. Nice...LMAO

I will no longer reply to any comments made by yourself or Darren in this thread

Prayers have been answered. Thanks.

 

[Grant808]

Doesn't matter if you measure it in meter, inches, peanuts, acorns, or miles.....

Great tech. :rollseyes I guess this is your way of saying that you didn't really understand what you were reading on BITOG.

There is a direct relationship between Viscosity in cSt and HT/HS in cP. When one reduces in viscosity, so does the other. You seem to deny this fact, or this fact doesn't conform to your agenda here.

I do not deny that some drop is likely. But I totally deny the accuracy of your 'estimates' based on the 100C cSt shear values and delta. I've found some of your old posts with terribly flimsy math that 'estimate' the shear drop 'percentage' based on taking average values and applying exactly half of that averaged percentage to the manufacturer listed virgin spec. Laughable to anyone who understands any sort of numerical analysis and propagation of errors. The only way to actually get these numbers would be to test the virgin sample in hand and test it again when it's used. The conviction with which you spout off numbers is comical.

Please continue to use what lubricant makes you feel good inside, that's what people do. You've answered no questions in this thread what-so-ever, only made quick conclusions that favor your point of view without trends to justify them. This conversation is concluded, and is no longer deemed productive to this thread. Besides, your use of the Boss 302 Roadrunner likely accounts for less than 1% of the percentile in this forum. Most people who own this car drive them on the street. I will no longer reply to any comments made by yourself or Darren in this thread.

Well you've certainly made some people feel good about choosing products that you sell.

Repeat or name a question that I didn't answer. You're great at the straw man arguments. As for my conclusions, I'm looking at the same data you posted.

'Less than 1%'. Haha. And there you go again with the comical math. This is a Boss sub forum...so guess which one of us is technically out of place here. I have met many other Boss owners and forum members in person at various tracks. I won't even speculate about the math, except it's nowhere *under* 1%.

 

[UnleashedBeast]

8,300 Boss 302 cars were produced for the 2012 and 2013 model years. Please list more than 83 members here at SVT Performance who own said car and who close course race it every season. Guys who race it once or twice for the "experience" do not count.

List must contain valid info (i.e. track location, frequency of competition)

Now, list total members who drive only on the street, or drag, or rare close course event.

 

[darreng505]

^^^^ lmao

op:

All new boss owners get a track day experience from Ford. Give them a call and ask how many registrations they've had for starters.
It's a "track car", not some gimmick.

http://www.bosstrackattack.com/

 

[Grant808]

8,300 Boss 302 cars were produced for the 2012 and 2013 model years. Please list more than 83 members here at SVT Performance who own said car and who close course race it every season. Guys who race it once or twice for the "experience" do not count.

List must contain valid info (i.e. track location, frequency of competition)

Now, list total members who drive only on the street, or drag, or rare close course event.

You're a joke with your straw man arguments.

All ~8,300 Boss owners are not members here.

"less than 1% of the percentile in this forum" would be the number of registered 'track rats' on SVTP over the registered Boss owners on SVTP.

I think I'm covered with the number of track rats I know or met personally on pages 1-3 of the Boss owner thread. Definitely covered by the guys I know of only on the 'net here. And that's not even the guys who no longer own their Bosses. I could even boil it down to the guys who have/own AT LEAST one set of dedicated track/race wheels+tires.

Seriously, you are bad at math. Or don't know how to type what you mean.

But if you want to prove me wrong, you need to find waaaay over 600 SVTP registered Boss owners who do not regularly track their car or whatever ridiculous definition you are going to say next. And that's my 3 minute 'proof' you don't know what you're talking about again. Knock yourself out counting.

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

 

[CodyK7]

My head hurts. That's alot of information. Where is the best place to buy it.

 

[Brewmaster]

I thought Dr. Oil was done? After posting this:

"This conversation is concluded, and is no longer deemed productive to this thread."

But I guess after 8,000 posts it is hard to quit!

 

[Swiss Boss]

I think both of them are correct to a certain point but miss some information.

When Grant ask about HTHS I looked for more info and then I found this thread that is pretty interesting

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2000048&page=1

Now my question for track car because that's all it's about.

Which one protect the engine better?

10w-40(Amsoil) @ 4.3 HTHS
http://www.amsoil.com/shop/by-produ...c-premium-protection-motor-oil/?code=AMOQT-EA
or
5w-50 (Castrol Edge) @ 3.7 HTHS
http://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/9A32D5E3D16D0C5B80257C1600466D1C/$File/BPXE-9AJFL6.pdf

I couldn't find the HTHS for the motorcraft 5w-50 so if somebody has it please post it.
But looking for other brand carrying Ford specification it looks like the HTHS is @ 3.7 (minimum required for a 50 grade oil)

I'm not a brand loyalist just looking for the best quality for $$.
So far Amsoil 10w-40 has been great for that

 

[Grant808]

Swiss Boss- I found the same info and was confused why UB doesn't just stick to the facts. The selling points seem strong enough, IMO. Just makes me wonder if there's a lack of understanding or something worse.

But through my searches, I've seen him claim that MC shears to 2.9 cP...or sometimes 3.1 cP...when he can't back up *that* claim with any factual testing. I don't get why it makes sense to mix the facts with heavy speculation.

 

[Swiss Boss]

I can't stop reading this subject. Very interesting but pretty difficult to understand.

Found another thread on BITOG about HTHS shears.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2501138

It seems that HTHS shears by half of what the viscosity shears. EX: if your oil shears by 10% then your HTHS only shears 5%

Quote from BITOG
/I tried but don't understand how the examples relate to both KV and HTHS viscosity. The latter is at one high temp of 150 C and a shear rate if 1 million per second. The former is at any temp. And a very low shear rate, driven by gravity only. Polymeric thickeners are what make the relationship between viscosity and shear rate a dependent one. The higher the shear rate, the lower the viscosity, generally. That's because the stress causes them to align in a way to reduce resistance to flow (reduce viscosity). When the stress is removed, the polymers that were not torn apart in the process go back to their original shape. That's called temporary shear. Permanent shear refers to when polymers are torn apart in the process and when the stress is removed, the KV is lower than what it was prior to the shear stress. Studies have found that when KV drops X percent from permanent shear, the HTHS viscosity drops around X/2 percent. This is because the polymers affect the KV much more than they do the HTHS viscosity.

The shear rate and temp. in the HTHS test were arrived at by analyzing a lot of data to find a good correlation between it and minimum oil film thicknesses in journal bearings and between piston rings and cylinder walls. I do not recall what engines were tested or what the oil temps. or load or RPMs were. To find this correlation with the HTHS test, they tried various temperatures and various shear rates. Each part of an engine causes different shear rates and temperatures, which varies by the engine type, load, oil properties, RPMs, and many other things. Yet, they ended up using one shear rate and temp. for the HTHS test. It does NOT completely replicate what oil experiences in every part of a hot engine; for example, oil on cylinder walls near TDC and BDC sees low shear rates because the piston speeds are low there. Oil consumption was found to decrease when polymer-containg oils with the same HTHS viscosity as monograde oils were used and it was attributed to higher actual viscosity of the multigrade oils on the cylinder walls. The HTHS test was necessitated by oils with polymers in them becoming prevalent. Monograde oils without polymers are Newtonian fluids so the viscosity is independent of the shear rate.

Those solvents are probably Newtonian fluids and the fluid shear rates were probably always much lower than 1 million per second. Sorry if my post does not address your comments or questions./

So quick math:
According to UB excel sheet, Motorcraft 5w-50 shears about 30% (average)
Then if MC 5w-50 has a HTHS @ 3.7 (still didn't find the number)
3.7 - 15% = 3.145

 

[Swiss Boss]

Grant, it seems UB number were correct. IF the guy from BITOG is correct which I believe is.

By the way do you know Ford HTHS recommendation for the coyote/roadrunner engine?

I don't know how low you can go to keep the engine safe in a road race. A
And too high is not a good option either.