Think M115W-50 HTHS5.1 was misprint.

[scout]

Old M1 15W-50 (SL) had a published HTHS of 5.1.
I now suspect that this was a misprint, after looking at other oils, and other M1 oils.
Does, or did, anyone else think this?

I'm now running Delo 400 15w40, with 4.3 HTHS. This compares well with M1EP 15W-50, a much thicker oil, at 4.43.

 

[buster]

No it's not a misprint. M1 EP is a reformulation. The HT/HS spec is the most over rated spec and part of the reason is this board. It's fixated on this particular spec. Unless your owner's manual says you need that spec to meet a requirment, don't worry about. My opinion is that most engines today don't need a very high HT/HS oil, as stated in that Shell study (it is only one study however). Different engine materials and better additives. Some of the best UOA's on this board are with oils with low HT/HS.

 

[Mr Magoo]

I still have a 2 year old case of M1 SuperSyn 15w50 , is it worth mixing this oil with Mobil 5000 ?

 

[JohnBrowning]

I disagree with buster on HTHS being the most over rated spec. Their are far less important spec.'s like cold flow temp., amount of additives that show up in $20 UOA, SAE viscosity etc..... I would rather we did away with SAE viscosity all together and instead just give an hths minimum a cold cranking number.

I would think that an HTHS of 3.3-3.6 would take care of 98% of vechiles sold in the USA if not being raced or driven as though they are being raced.I think that you really need to have some special needs to take advantage of an oil with an HTHS above 3.6. I would rather have an oil that can maintain it's HTHS then one that starts out high and then shears like crazy.

I think that M1 15W50 is a great product if you really have a need for it but few do. I also think that modern synthetic and semi-synthetic 5W40's are a much better match for most people then 15W50 or 15W40.

As far bearing materials go the only company that I am aware of with any type of exotic propriatary matrix is Honda the rest of the industry is useing industry standard materials and matrix's/matricies(sp).

 

[427Z06]

I agree with buster. Unless your engine has a particular need for an oil that has a particular HTHS, it shouldn't be a concern. It's a fool's logic to think that 4 aspirins are going to be twice as good as 2 in every circumstance. Engine manufacturers test their engines with oils of various grades and HTHS and build their recommendations accordingly. Recall that HTHS is a measure of the viscosity of an oil at a particular temperature, in a particular way, namely under high shearing. Thus for example, if the components in your engine don't see the same temperatures as that of the HTHS test, and that of an engine that does, without any testing, how can one determine that you are lacking in this particular viscosity measurement? If you live in Puerto Rico, are you going to ask someone in Alaska whether you need a coat to go outside today?

Many people like to point to one particular test from the early '90s as the holy grail of engine wear based on HTHS, but don't let these thick headed curmudgeons bamboozle you. There are other equally valid tests that show that the modern oils specified for your engine provide all the protection you need for the conditions your vehicle is going to see on public roads.

Wouldn't it be fun if oil manufacturers published the pressure-viscosity coefficient of their formulations? Cause I'm sure it wouldn't be long before someone here decided an a priori minimum value for it too. Although, I still wonder how much it hurts when they pull these numbers out of their you know where.

 

[sands]

quote:

---

Originally posted by buster:
No it's not a misprint. M1 EP is a reformulation. The HT/HS spec is the most over rated spec and part of the reason is this board. It's fixated on this particular spec. Unless your owner's manual says you need that spec to meet a requirment, don't worry about. My opinion is that most engines today don't need a very high HT/HS oil, as stated in that Shell study (it is only one study however). Different engine materials and better additives. Some of the best UOA's on this board are with oils with low HT/HS.

---

If HTHS is the most over rated spec, then what is the most under rated spec ?

 

[Mitch Alsup]

I see two problems here::

A) some engines need a bigger HTHS number than others
B) Some users and some applications are tougher than others

As to A) valve actuation by direct contact with the cam shaft require higher HTHS numbers due to wiping forces at the cam lobe. These engine architectures are not ameanable to rollerization of the cam lobe faces as are in block cam architectures. Thus, other than making the lobes bigger and making the cam lobes softer with respect to accleration forces, little cam be done in the compact combustion chambers typical of these engines.

As to B) the best indication that one is going to have an HTHS problem is an oil temperature guage, which precious few cars these days have! Secondly, the cure for 95%+ of the engines that runs with high oil temperatures is not an oil with higher HTHS numbers, but (gasp) an oil cooler! possibly with a (gasp again) a fan!

 

[427Z06]

Very well put, Mitch. Once again you beautifully illustrate the folly of over-generalized specification recommendations and the proper solution to taming the beast related to this variable.

 

[buster]

427Z06 and Mitch hit the nail on the head IMO.

quote:

---

Many people like to point to one particular test from the early '90s as the holy grail of engine wear based on HTHS, but don't let these thick headed curmudgeons bamboozle you

---

Completely agree.

 

[scout]

Old M1 15W-50 (SL) had a published HTHS of 5.1.
I now suspect that this was a misprint, after looking at other oils.
Did anyone here ever question it, or test it?

 

[scout]

quote:

---

Originally posted by buster:
No it's not a misprint.

---

How do you know? Did you test it?

 

[bruce381]

working on the Lubrizol site I quickly came up with a 5.15 HTHS 15/50 oil using NO VII's
so I'd say the M1 info is correct or at least doable.
bruce

 

[radiometer]

John Browning: You've made your point with me. From reading your post and those of others I find you made the far better point. When I can get higher HTHS with its better protection why shouldn't I?

The others just didn't make convincing arguments.

I'm glad you're here.