Is 20W20 a mono-grade?

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What defines a mono-grade? The absence of classic VIIs, the absence of any additives that modify the viscosity or the inability of an engine oil to pass a W cold cranking and pumping classification below it's SAE grade?
 
The lack of VII's.

If an oil without VII's is also run through the CCS/MRV testing it can be labelled as either a multigrade (like 20w-20 or 15w-20...etc) or a monograde.
 
So by definition, a PAO synthetic could pass 5W30 by virtue of it's inherent high VI, but be labeled and marketed as an SAE 30?
 
Originally Posted By: used_0il
So by definition, a PAO synthetic could pass 5W30 by virtue of it's inherent high VI, but be labeled and marketed as an SAE 30?


Correct. And why AMSOIL's 10w-30 HDEO can be both (and I think they have one that is IIRC).

I believe Redline's 5w-30 is an example of what you just mentioned (and why it doesn't shear). A primarily PAO and POE oil that needs no VII's to obtain its w-rating.
 
Could Redline label that 5W30 engine oil a 10W30 instead, or do they have to leave it a 5W30 because if marketed as a multi-grade, it has to be labeled at the lowest W number it passes?
 
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Most oils will meet the viscosity requirements of at least one of the W grades. Nevertheless, consistent with historic practice, any Newtonian oil may be labeled as a single-grade oil (either with or without a W). Oils which are formulated with polymeric viscosity index improvers for the purpose of making them multiviscosity-grade products are non-Newtonian and must be labeled with the appropriate multiviscosity grade (both W and high-temperature grade).


Covers the Amsoil ACD case, it's an SAE30 that meets 10W as well, so can carry both.

20W20 in practice is Newtonian, although in theory, and I don't know why you would, you could put VIIs in it and chase the grade minimum 2.6HTHS...Joe90_Power reckons he has a recipe for a VI free 10W20.
 
Originally Posted By: used_0il
Could Redline label that 5W30 engine oil a 10W30 instead, or do they have to leave it a 5W30 because if marketed as a multi-grade, it has to be labeled at the lowest W number it passes?


Correct, it has to be labelled at the lowest W-rating it can obtain.
 
It you go back several decades, I suspect that once upon a time, the difference between monograde and multigrade was very pronounced and that difference was the presence or absence of VII.

Nowerdays however, the distinction has become much more blurred. The widespread availability of high VI base oils, particularly PAOs, mean it's easy to make a VII-free oil that complies with multigrade requirements.

Also, as people have realised you don't need high KV100 to avoid wear, there has been a natural 'narrowing' of viscosity grades which can push you in the direction of VII-free multigrades. I don't know for sure but I suspect that the Ravenol OW16 oil is likely to contain no VII.

It's also worth pointing out that even a VII-free oil, still contains stuff that acts as VII. Polymethacrylate PPDs are natural VIIs and high molecular weight ashless dispersants also act like VIIs (albeit not very good ones).

The only area where the distinction really still matters is marine lubricants. Traditionally you would make heavy monogrades with heavy Bright Stock. However as the industry has moved away from traditional Group I manufacture, [censored] has become both expensive and short in supply. I have heard a couple of rumours of people substituting VII for [censored] in marine lubricants and things ending in tears because VII gums up the works.

My personal opinion is that any move to no, or low, VII multigrade oils is a good thing. Most formulators learn very quickly that VIIs are The Spawn Of [censored] and the root of all things evil. I for one will not mourn their passing!
 
There seems to be a lot of group III capacity in North America as of late.
Those base oils have a viscosity that peak out right around where SAE 16 is going to be.

So you can figure out where I'm going with this.

Will 5W16 and 0W16 be Newtonian and if so, how will that affect the HTHS when comparing these two grades to the (higher VI) 0W20 and 5W20s?
 
Originally Posted By: Joe90_guy
I have heard a couple of rumours of people substituting VII for [censored] in marine lubricants and things ending in tears because VII gums up the works.


Over the last 5 years, I've had ISO 320s, and 1,000s shear down to near nothing...could this be the issue ?

The manufacturers deny adding polymers, but a 1,000 becoming a 400 in 2 weeks is crazy.
 
For the new LV multi-grades, only enough VII will be added to get to a target viscosity or viscosity range, since the high VI "true" synthetics will carry most of the viscosity indexing.
 
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I think the answer to your question depends on what base oils get used to make the oils.

Both a 5W20 & 5W16 oil, if made the traditional US way with Group II, will need to contain VII to make this viscometric balance work. On the other hand if you make them from Group III/IV you take them into VII-free territory. As soon as you make them VII-free, the fluid becomes much more Newtonian and the correlation between KV100 and HTHS much more direct.
 
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Haha, I'm 50% highlander, so that doesn't apply to me.

In response to Mola's post, would the 0W16 be PAO and the discount 5W16 be II/III blends if the object was to keep those blends VII free?

Caterpillar drive train fluids (TO-4s) have some strict rules attached to their approval process. I believe VII free is one of the requirements.
Yet I see mono-grade SAE30s passing 15W from oil companies known to call group IIIs .....synthetic. (The Horror)

I would imagine they achieved the cold flow in part by Joe's bright stock one end of the blend,
group II in the middle and group III to hit the cold performance target.

Apply that to 5W16 and we have a $1.99/L GF-6.

So much fun so little time. If 68 grains is the powder charge, how much does the bullet weigh?
 
32.gif

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If 68 grains is the powder charge, how much does the bullet weigh?


That was in reference to a .223/5.56 MIL round.
smile.gif
 
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Hi,
used_oil - the 20W-20 viscosity was very popular in the 1950s>. Castrol's "Castrolite" was used in all BMC "A" and "B" series engines of that era. It was a durable product.

It was superceded in 1959 by Duckhams Q20W-50 and Castrol's XL 20W-50 as the BMÇ Mini's combined gearbox/engine power unit demanded a higher viscosity as it was very hard on the lubricant (permanent shear)

The 20W-50 viscosity along with 10W-30 became the mainstays as 20W-20 progressively took a back seat
 
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