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

[ARCOgraphite]

You are quite welcome!

But we still have the mystery of dual rated PHOS limits from my quoted article. I just reviewed my old files and then perused new API CK-4 oils on the Shell site.
Where there were in the past many Dual Rated or Multi Fleet API CI-4/SM Rotella T4, T5, T6. I see now few current 10W30 or 5W40 showing an API SM or SP approval - Just JASO on the T6. I would guess the industry is understandably trying even harder to keep high SAPS 30 grade lubricants out of emission-controlled, converter equipped cars and light trucks - where sneeky BITOGer's look for a work around

_________________________________

UPDATE: I just found this dual rated outlier. I have never heard of this product but I am not the target consumer.
Also found the old 0W40 low saps "arctic blend" 0W40 is dual rated API SN

https://rotella.shell.com/en_us/products/triple-protection-motor-oil/shell-rotella-t4-natural-gas-engine-oil/_jcr_content/par/productDetails.stream/1588186106468/08c995bb82018ce3e2e09cd089383e7f51499814/shell-rotella-t4-ng-plus.pdf

Now I just found this 5W30 (!) Dual rated that busted my theory above, oh the agony!
Is it low phos < 0.08 % ? A very interesting oil - check it out. There are colour dirty TC housing and piston pics too!

https://rotella.shell.com/en_us/products/full-synthetic-oil/shell-rotella-t6-multi-vehicle-5w-30-full-synthetic-heavy-duty/_jcr_content/par/textimage.stream/1506812713065/6497cd0c8790462590b535326756b2b5e1144d44/t6-multi-vehicle-5w-30.pdf

 

[Fasternet]

Why do you prefer the Castrol?

Sorry for the delay. It's just that I've used Castrol products for quite some time now and have had good results with them. Cannot give you a technical reason.

 

[userfriendly]

It certainly won't tell you if it would pass the requirements for any of the approvals. That poster has some uninformed notions.

You guys sound like my grandmother's bridge club in a henhouse with weasels.

What's the infatuation with 0W engine oils, ya' all heading to the north pole?

 

[Slow Car Sport Mode]

You guys sound like my grandmother's bridge club in a henhouse with weasels.

What's the infatuation with 0W engine oils, ya' all heading to the north pole?

0W oils tend to have of a higher quality base stock blend to be certified 0W. It is the overall formulation that matters the most, however.

Now, if you want to really have fun? 0W oils can run "thicker" than a 5W or even 10W at full operational temperature because of the formulations, I believe Mobil 1 0W, 5W and 10W-30 (0W-30, 5W-30, 10W-30? Or was it 40) was compared. But don't quote me on that.

I can get some Red Bull and some marbles and we can play anagrams and have a Pinewood Derby with different kinds of oils on a track if you REALLY want to pull an all-nighter and geek out! And if you fall asleep early and don't stay up all night.. you have to KISS THE FROG! Ohh we can have fun

 

[RooflessVW]

What's the infatuation with 0W engine oils, ya' all heading to the north pole?

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...?

 

[Slow Car Sport Mode]

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...?

If you're in extreme cold part of Canada you might want a 0W.

That's about it.

 

[Arrow]

Picked up a couple of jugs of M1 FS 0w-40 yesterday. Thanks for the info, everyone. Good oil. Good peace of mind (zinc).

 

[kschachn]

You guys sound like my grandmother's bridge club in a henhouse with weasels.

What's the infatuation with 0W engine oils, ya' all heading to the north pole?

What parts of a $30 spectrographic analysis do you look out to determine if an oil meets the entirety of the requirements for an approval?

And I really don’t care what the winter rating is as long as it’s appropriate for my expected starting conditions. After that I couldn’t care less. For me it comes down to what is the demonstrated real-world performance that results in obtaining a demanding approval.

 

[Greasymechtech]

Picked up a couple of jugs of M1 FS 0w-40 yesterday. Thanks for the info, everyone. Good oil. Good peace of mind (zinc).

Easy to find and not priced like unobtainium. History of UOAs here and elsewhere. Probably the best 30 grade I've ever used.

 

[OVERKILL]

Picked up a couple of jugs of M1 FS 0w-40 yesterday. Thanks for the info, everyone. Good oil. Good peace of mind (zinc).

Excellent choice!

 

[ZeeOSix]

In case it helps, here's the API guide itself:

https://www.api.org/-/media/Files/Certification/Engine-Oil-Diesel/Publications/API%201509-%2021st%20Edition.pdf?la=en&hash=D9D1AFFC9F17378FE72827CB0809EC26B4928AA1

You'll also note "Resource Conserving" applies to all grades.

Side note - notice that different viscosity oils have different test "Performance Criteria" to be labeled as "Resource Conserving". Snips from pages 10 and 11 of the API guide.

Also, notice that the Performance Criteria changed quite a bit between API SP and API SN (pages 11 and 12).

 

[Arrow]

0W oils tend to have of a higher quality base stock blend to be certified 0W. It is the overall formulation that matters the most, however.

Now, if you want to really have fun? 0W oils can run "thicker" than a 5W or even 10W at full operational temperature because of the formulations, I believe Mobil 1 0W, 5W and 10W-30 (0W-30, 5W-30, 10W-30? Or was it 40) was compared. But don't quote me on that.

I can get some Red Bull and some marbles and we can play anagrams and have a Pinewood Derby with different kinds of oils on a track if you REALLY want to pull an all-nighter and geek out! And if you fall asleep early and don't stay up all night.. you have to KISS THE FROG! Ohh we can have fun

I'd love to learn more about that. Something so counterintuitive would be fun to understand better.

 

[kschachn]

I'd love to learn more about that. Something so counterintuitive would be fun to understand better.

The winter rating isn’t necessarily directly determinate of the operating viscosity. It’s not a “0 weight” or a “5 weight” oil. The same variation in viscosity within the grade still exists regardless of the winter rating. It’s not really counterintuitive if you understand what the winter rating means and what it does not mean.

 

[ZeeOSix]

Maybe some people think "W" means "weight" ... of course, it doesn't.

 

[JohnnyJohnson]

Maybe some people think "W" means "weight" ... of course, it doesn't.

My vote goes for Woke!

 

[ZeeOSix]

My vote goes for Woke!

... they aren't "woke" to oil if they don't know what "W" stands for.

 

[Arrow]

The winter rating isn’t necessarily directly determinate of the operating viscosity. It’s not a “0 weight” or a “5 weight” oil. The same variation in viscosity within the grade still exists regardless of the winter rating. It’s not really counterintuitive if you understand what the winter rating means and what it does not mean.

Ah, ok. So a zero is just a relative flow at winter temperatures? A 40 weight that flows at a value of 0 in winter?

Obviously, I’m not afraid to look stupid.

 

[OVERKILL]

Ah, ok. So a zero is just a relative flow at winter temperatures? A 40 weight that flows at a value of 0 in winter?

Obviously, I’m not afraid to look stupid.

The number in front of the W is the Winter rating of the oil. It's a set of viscosity limits, measured via two separate tests, run 5C apart.

The first test is CCS - Cold Cranking Simulator, this has the lower of the two limits and is measured at a 5C higher temperature. It is designed to determine the impact on cranking speed (which could lead to a no start)

The second test is MRV - Mini Rotary Viscometer, this has a broader limit (most oils fail CCS first) and is measured at a 5C lower temperature. It is designed to ensure the oil will pump. Pretty self-explanatory.

So, if you look at SAE J300, you can see that for the 0W-xx Winter rating, CCS is measured at -35C and MRV at -40C:

As you go up the Winter ratings, the temperatures go up in 5C increments, and the numbers themselves change.

 

[Slow Car Sport Mode]

Ah, ok. So a zero is just a relative flow at winter temperatures? A 40 weight that flows at a value of 0 in winter?

Obviously, I’m not afraid to look stupid.

Not so much a "value of zero," it is a 30 or 40 grade oil no matter what. The W number or Winter number is supposed to be the rating of "Resistance To Flow."

People like to say (and they are wrong) that oil would "Start out as a zero and warm up to a 40." Again, that is not correct but I've heard it said and makes my brain explode.

Was going to say the W number, or winter "rating," was supposed to denote "Resistance to flow" as in.. a 0W will "flow" in the cold better than a 5W, a 5W will "flow" better than a 10W, a 10W will "flow" better than a 15W, a 15W will "flow" better than a 20W, etc. Here is the Brittanica definition of viscosity. https://www.britannica.com/science/viscosity

I would question the last two paragraphs of this quote from article, since we are here. https://lubricants.totalenergies.com/consumers/maintenancetips/Oil-viscosity-and-oil-grades

Viscosity is notated using the common classification “XW-XX”. The number preceding the “W” (winter) rates the oil’s flow (viscosity) at zero degrees Fahrenheit (-17.8 degrees Celsius). The lower the number, the less the oil thickens in cold weather.

The numbers after the “XW” indicate viscosity at 100 degrees Celsius and represent the oil’s resistance to thinning at high temperatures.

For instance, oil with a 5W-30 grade thickens less than oil with a 10W-30 grade in cold weather. Oil with a 5W-30 grade thins out more quickly at high temperatures as compared to oils with a 5W-40 grade.

During winter and for cars used in cooler regions, your engine will benefit from using oil with low winter viscosity. During summer and in hotter regions, your engine will benefit more from oil with higher viscosity at 100 degrees Celsius.

 

[Arrow]

Not so much a "value of zero," it is a 30 or 40 grade oil no matter what. The W number or Winter number is supposed to be the rating of "Resistance To Flow."

People like to say (and they are wrong) that oil would "Start out as a zero and warm up to a 40." Again, that is not correct but I've heard it said and makes my brain explode.

Was going to say the W number, or winter "rating," was supposed to denote "Resistance to flow" as in.. a 0W will "flow" in the cold better than a 5W, a 5W will "flow" better than a 10W, a 10W will "flow" better than a 15W, a 15W will "flow" better than a 20W, etc. Here is the Brittanica definition of viscosity. https://www.britannica.com/science/viscosity

I would question the last two paragraphs of this quote from article, since we are here. https://lubricants.totalenergies.com/consumers/maintenancetips/Oil-viscosity-and-oil-grades

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?