What is "Plan B" if I can't get Amsoil Z-Rod for My 1990 Corvette ZR-1.

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Thanks.
You've just nailed my confusion with the whole thing. I read a number of articles, for what can be considered articles nowadays, and they described it as you do in your second paragraph. Or others equally nonsensical.

It ain't easy to sort out. But, if I'm reading your description right, a 0W-40 will not flow thicker then a 40 in the cold? While a 5W-30 will flow thicker then a 30 in the cold. Does that make sense?

Hey, thanks, no problem, and I thank you. I had an interaction with a YouTuber that infuriated me, pretty much on the basis of incorrect oil information. The rest is history. I've dedicated my life to the truth. So let's continue with what you're learning, before I have to break away for a bit.

The short answer is that the way you summized it is not correct. Let me focus, and explain.

You summized:

But, if I'm reading your description right, a 0W-40 will not flow thicker then a 40 in the cold? While a 5W-30 will flow thicker then a 30 in the cold. Does that make sense?

While I see where you are thinking, the short answer to that is, no, that is not it.

a 0W-40 will not flow thicker then a 40 in the cold?

Fundamental to understand, and what will set you apart in your superior oil knowledge to others, is that it is always a 40 in that example. The first number has nothing to do with the second.

If you are talking about a monograde 40, then that is correct. A monograde oil has no W or Winter rating.

People that think it does are, bluntly, not correct. This is the source of much misinformation.

The first number is separate from the second.

While a 5W-30 will flow thicker then a 30 in the cold?

This is the most confusing part of all. Some 5W will flow better than 0W.

I now yield the floor.
 
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It’s really not about flow, at least not in the sense of oil “flowing” in the engine. If the pump can pump the oil then it will flow. For the most part the concept of flow in the engine is not relevant. Pay more attention to Overkills’s description above as that is correct.

Multi-viscosity oils thicken less than a monograde when cold but it’s all about temperature as is illustrated above. It’s about pumping and cranking, if the oil can’t be pumped it’s not going to flow and engine failure will result. The only flow that’s really important is the flow under shear in the vicinity of the oil pump pickup tube so that the pump doesn’t cavitate or starve. This is only a concern at low temperatures and is what the winter rating represents. As long as the oil you’re using has a winter rating that’s appropriate for your expected starting temperature then flow is not an issue.
 
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*cough*Rotella*cough*

But IMO, any Euro spec oil such as M1FS 0W-40, Castrol Edge Euro Car 0W-40 or 5W-30 A3/B3, or PP Euro(also carries dexos2 approval) would be fine.

Also, I think XOM released a new dexosR oil for the new Corvette/Camaro for track use that should also be fine.
 

OVERKILL

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If you are talking about a monograde 40, then that is correct. A monograde oil has no W or Winter rating.

People that think it does are, bluntly, not correct. This is the source of much misinformation.
Not quite. A monograde is an oil with no VII in it (no Viscosity Index Improvers). Many monogrades do in fact carry a Winter rating, or are dual-labelled. AMSOIL famously sold a 10W-30 that was also an SAE30 for ages, HPL currently sells a 15W-30 monograde. Whether a company chooses to test the Winter rating of the monogrades they sell, or note it on the bottle, is on them. You aren't required to call out the Winter rating unless the oil has VII in it.
This is the most confusing part of all. Some 5W will flow better than 0W.
No, a 0W-xx will always have better cold temperature performance than a 5W-xx, that's the whole point of the Winter rating. Where it gets confusing is that you can have a 0W-xx that's thicker at basically all temperatures a bit above where the Winter rating is measured. For example, a 5W-20 vs a 0W-40, at some point, the 5W-20 fails the Winter rating limits to carry the 0W-xx designation, typically CCS, so at -35C, it's thicker than the 0w-40. What does that look like at -30C? -25C? At some point there the 0w-40 is thicker, but there's a crossover point where it thickens less. This may be due to lighter base oils and more PPD's, it may be due to PAO content...etc.
 
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Not quite. A monograde is an oil with no VII in it (no Viscosity Index Improvers). Many monogrades do in fact carry a Winter rating, or are dual-labelled. AMSOIL famously sold a 10W-30 that was also an SAE30 for ages, HPL currently sells a 15W-30 monograde. Whether a company chooses to test the Winter rating of the monogrades they sell, or note it on the bottle, is on them. You aren't required to call out the Winter rating unless the oil has VII in it.

No, a 0W-xx will always have better cold temperature performance than a 5W-xx, that's the whole point of the Winter rating. Where it gets confusing is that you can have a 0W-xx that's thicker at basically all temperatures a bit above where the Winter rating is measured. For example, a 5W-20 vs a 0W-40, at some point, the 5W-20 fails the Winter rating limits to carry the 0W-xx designation, typically CCS, so at -35C, it's thicker than the 0w-40. What does that look like at -30C? -25C? At some point there the 0w-40 is thicker, but there's a crossover point where it thickens less. This may be due to lighter base oils and more PPD's, it may be due to PAO content...etc.

Excellent post, OVERKILL. Let me just quickly state that I should have done a better job of pointing out, but didn't.. so I went back and quoted, for where I was drawing inference from.. Italicizing and asterisking the parts I meant to pair together:

(It was one line up. Again, error on my part.)

Fundamental to understand, and what will set you apart in your superior oil knowledge to others, is that it is always a 40 in that example. *The first number has nothing to do with the second.

If you are talking about a monograde 40, then that is correct. A monograde oil has no W or Winter rating.

People that think it does are, bluntly, not correct. *This is the source of much misinformation.

I did end up lumping monogrades in, because I was thinking of any which direction OP could make inference from. He originally asked if a 0W-40 would flow better than a 40.. is where I got that from, at all.

OP quote:

But, if I'm reading your description right, a 0W-40 will not flow thicker then a 40 in the cold? While a 5W-30 will flow thicker then a 30 in the cold. Does that make sense?
 

ZeeOSix

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It ain't easy to sort out. But, if I'm reading your description right, a 0W-40 will not flow thicker then a 40 in the cold? While a 5W-30 will flow thicker then a 30 in the cold. Does that make sense?
You have to look at the "W" as a totally separate flow characteristic than the hot "30" or "40" part of the viscosity rating. Example: 5W-20, 5W-30, 10W-40, 5W-50 etc, where th bold 20, 30, 40 and 50 part are the hot viscosity grades defined by SAE J300.

The "W" (Winter) viscosity grade is ONLY describing the viscosity at very cold temperatures for engine cranking and oil flow to the oil pump type of flow characteristics. @OVERKILL (with the SAE J300 info - post #138) and others have already explained that well. The hot viscosity (the kinematic viscosity measured at 100 deg C - aka the "KV100" which means "Kinematic Viscosity @100C") is the viscosity when the oil is hot (ie, engine operating temperature hot).

So you need to separate the xW part from the -30 or -40 part of the multi-viscosity rating to make total sense of reading the xW-yy multi-grade rating.
 
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ZeeOSix

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This is the most confusing part of all. Some 5W will flow better than 0W.
Maybe in a Project Farm "cold oil race" ... but that is NOT how cold oil flows in a CCS or MRV test machine (used to determine the SAE J300 "W" rating) which simulates what's happening inside an engine better than a PF cold oil flow race. This was all discussed in a couple other threads recently about how the PF cold oil flow race doesn't correlate to the CCS or MVR viscosity of those same oils he races against each other.
 

ZeeOSix

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^^^ Here's the post I was talking about showing that the PF cold flow races do not always reflect how the oil would actually pump and flow inside an engine during a cold start-up. All of those Penzzoils were rated 5W, but if you compared their actual CCS viscosity and ranked them, they did not rank in the same order as the cold flow race. So no real correlation between CCS viscosity and cold pour point flow viscosity

 
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^^^ Here's the post I was talking about showing that the PF cold flow races do not always reflect how the oil would actually pump and flow inside an engine during a cold start-up. All of those Penzzoils were rated 5W, but if you compared their actual CCS viscosity and ranked them, they did not rank in the same order as the cold flow race. So no real correlation between CCS viscosity and cold pour point flow viscosity


I don't endorse anything to do with the joke of stuff known as Project Farm and also don't look at those videos.

I've always thought, perhaps even read about which is why I would make that statement at all, .. a "thin" 30 with more superior base stock oils, if going by HTHS ratings, would have better cold performance than a "thick" 30 with some lesser base stock oils, perhaps like a GC 0W-30 for thick vs something like a Pennzoil Ultra Platinum or more Advanced fully formulated 5W-30s. I could expand on one more aspect but this has been a topic of conversation at times. A "superior" or "newer" as per API 5W vs an older 0W.

You're mentioning CCS and MRV tests making an oil a 0W better cold performing than a 5W, if that is in every instance is what I am not quite grasping, maybe. Since we are steering both me and OP on the right path. Every oil?

Project Farm doesn't understand that oil gets sucked up, not run down, on startup.

Moving on from Project Farm, I think OP sees about the first number being separate from the second, which some people don't understand is one of the most basic things about motor oil, which you may find in subpar Internet videos about suggesting the two numbers are related when they are not.

Motor oil enthusiasts, unite!
 

ZeeOSix

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I've always thought, perhaps even read about which is why I would make that statement at all, .. a "thin" 30 with more superior base stock oils, if going by HTHS ratings, would have better cold performance than a "thick" 30 with some lesser base stock oils, perhaps like a GC 0W-30 for thick vs something like a Pennzoil Ultra Platinum or more Advanced fully formulated 5W-30s. I could expand on one more aspect but this has been a topic of conversation at times. A "superior" or "newer" as per API 5W vs an older 0W.
All sepulation until the CCS and MRV viscosity of each one was tested and compared to each other. SAE came up with the CCS and MRV test, and defined the "W" winter grades in SAE J300 for a reason.

You're mentioning CCS and MRV tests making an oil a 0W better cold performing than a 5W, if that is in every instance is what I am not quite grasping, maybe. Since we are steering both me and OP on the right path. Every oil?
If an oil is SAE J300 rated as a 0W it HAS to perform better in the CCS and MRV tests then one rated as a 5W. And those tests are what simulates how cold oil performs in an engine during very cold starts (CCS for engine cranking) and getting pumped by the oil pump (MRV for pumpability). Cold oil flow gravity races like on Project Farm don't simulate cold engine cranking and pumpability of the oil like CCS and MRV does ... that's whey there isn't really any correlatioin. The link in post #148 shows there is no real correlation between cold oil flow races and CCS viscosity.

Keep in mind that there is a range in all the J300 grades, so it's possible that one oil rated 5W could have a CCS viscosity that is lower or higher than other 5W rated oils. You would have to compare all of the measured CCS viscosities to know that. But they would still all be rated 5W, and all seem thicker to an engine during very cold winter starts as com;pared to a 0W rated oil.

Moving on from Project Farm, I think OP sees about the first number being separate from the second ...
Not so sure from what I'm reading ... but there is hope for everyone if they dig into it all like everyone else who is an oil enthusiast. :)
 
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It just so happens that some of the finest oils meeting the toughest specifications are 0W-30 and 0W-40 oils.

IMO when discussing oils meeting multiple specifications from German OEMs, the difference between each grade is negligible.

A great example Mobil 1 ESP 0W-30 vs 5W-30. The real difference between them is...?
Yes, when comparing 0w40 vs 0w40 or 5w30 vs 5w30.
If the toughest specifications were hard to pass, then 0w40 with all the certs wouldn't be on sale for $20 a gallon.
 
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Any dexos2 will be fine for your ZR1 :)

With the C8, GM started using a special M1 ESP 0w40 that's dexos2 and then back-spec'd it to all Corvettes. You could use that, or PP Euro L, or any other dexos2 you can get your hands on.

Alternatively, you could always use the regular M1 0w40. It is probably popular in pre-C8 Corvettes.
 
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