HPL SAE 40 PCMO

[C 'N Oils]

Never mind, I shall eventually look up traction. Could be, HPL has it somewhere on a homepage or so.

 

[scrllock]

Never mind, I shall eventually look up traction. Could be, HPL has it somewhere on a homepage or so.

It is somewhat misrepresented in his post. Claiming PAO/Star Polymer oils suffer from high traction heating is incorrect. PAO is utilized specifically to minimize traction coefficients.

 

[cheesepuffs2]

Pardon my ignorance, but what does the traction coefficient of an oil actually matter for street-driven engines?

 

[C 'N Oils]

Somewhere found that word he never should have found, and no one's proved friend enough to help out. That's why I'm even asking, where.

 

[tired]

Somewhere found that word he never should have found, and no one's proved friend enough to help out. That's why I'm even asking, where.

Reading your posts makes me feel like I'm having a stroke.

 

[scrllock]

Pardon my ignorance, but what does the traction coefficient of an oil actually matter for street-driven engines?

I don't believe it does.

 

[Hohn]

This is a really thoughtful and insightful analysis. Thank you. Might inform my oil choice, as I am firmly in the short trip, multiple cold and warm starts, low oil temps camp, and I seem to have a very effective oil cooler, as even after longer trips with highway usage, my oil seems to be around 155F. I don't have an oil thermometer, but I bought a laser thermometer and crawl under the truck after I park and check the oil pan temp. (So that temp obviously isn't on the highway, but after exiting and driving through neighborhoods.)

You’re not alone in such a duty cycle. In these cases, I think the HPL Premium Plus PCMO is a better fit than Supercar. Same excellent base oil blend concept, but a detergent pack more suited to the application.

 

[Hohn]

It is somewhat misrepresented in his post. Claiming PAO/Star Polymer oils suffer from high traction heating is incorrect. PAO is utilized specifically to minimize traction coefficients.

VIIs increase traction.
PAOs are very low traction.

I don’t think I claimed that PAO /star oil suffered from “high traction”. Rather, I pointed out that an oil that depends on its hths coming from VII will generally have higher traction than an oil of identical HTHS with a thicker base oil and less VII. The traction increase from having VII is larger than the decrease from having a PAO base.

GTL bases are particularly low traction. And a GTL with little to no VII will have lower traction than an oil oil built on thin PAO and a heavy dose of even star polymer.

So it’s likely if you built Supercar 0w-40 and PCMO SAE 40 to identical kv100s, the Supercar would have higher traction than the PCMO.

Higher traction does raise some temperatures in some locations, but let’s not overstate the degree to which this occurs.

 

[cheesepuffs2]

VIIs increase traction.
PAOs are very low traction.

I don’t think I claimed that PAO /star oil suffered from “high traction”. Rather, I pointed out that an oil that depends on its hths coming from VII will generally have higher traction than an oil of identical HTHS with a thicker base oil and less VII. The traction increase from having VII is larger than the decrease from having a PAO base.

GTL bases are particularly low traction. And a GTL with little to no VII will have lower traction than an oil oil built on thin PAO and a heavy dose of even star polymer.

So it’s likely if you built Supercar 0w-40 and PCMO SAE 40 to identical kv100s, the Supercar would have higher traction than the PCMO.

Higher traction does raise some temperatures in some locations, but let’s not overstate the degree to which this occurs.

What’s the relevance of traction in a motor oil outside of a racing environment where every thousandth of a second counts?

 

[scrllock]

VIIs increase traction.
PAOs are very low traction.

I don’t think I claimed that PAO /star oil suffered from “high traction”. Rather, I pointed out that an oil that depends on its hths coming from VII will generally have higher traction than an oil of identical HTHS with a thicker base oil and less VII. The traction increase from having VII is larger than the decrease from having a PAO base.

GTL bases are particularly low traction. And a GTL with little to no VII will have lower traction than an oil oil built on thin PAO and a heavy dose of even star polymer.

So it’s likely if you built Supercar 0w-40 and PCMO SAE 40 to identical kv100s, the Supercar would have higher traction than the PCMO.

Higher traction does raise some temperatures in some locations, but let’s not overstate the degree to which this occurs.

Traction is primarily dictated by the base oil, not VII. A 0w40 is almost assuredly a lighter base oil than a straight 40 grade, which would have less traction. Again, though, the difference is essentially meaningless.

What’s the relevance of traction in a motor oil outside of a racing environment where every thousandth of a second counts?

The actual difference in the coefficients here is going to be measured in the thousandths. It is statistically insignificant.

 

[Hohn]

Traction is primarily dictated by the base oil, not VII. A 0w40 is almost assuredly a lighter base oil than a straight 40 grade, which would have less traction. Again, though, the difference is essentially meaningless.


The actual difference in the coefficients here is going to be measured in the thousandths. It is statistically insignificant.

I think you are right, but it is both highly context dependent (i.e bearings vs rings etc) and indeed the differences are small.

Mostly traction differences show up when discussing contrasts like cheap mineral oil bases vs premium PAO or GTL bases.

 

[C 'N Oils]

The lower traction of the HPL oils is allowing me to have the thicker oil films (and lower wear) of the 40 grades while keeping the mpg of a 30 grade.

The actual difference in effect was said to be like falling down a Kellertreppe, just not equally wearsome.

 

[mt23]

This is a really thoughtful and insightful analysis. Thank you. Might inform my oil choice, as I am firmly in the short trip, multiple cold and warm starts, low oil temps camp, and I seem to have a very effective oil cooler, as even after longer trips with highway usage, my oil seems to be around 155F. I don't have an oil thermometer, but I bought a laser thermometer and crawl under the truck after I park and check the oil pan temp. (So that temp obviously isn't on the highway, but after exiting and driving through neighborhoods.)

Curious if measuring elsewhere could potentially give a more accurate reading such as the oil filter. I have observed a vehicle with oil temperature sensor having the most accurate reading at the hottest reading on the oil filter, with the pan and other parts of the block and heads being several degrees lower

 

[UGASpike]

But if you have a TGDI or GDI commuter that loafs along on the highway or slugs through traffic from light to light with nothing sexy, you probably want the D1G2 type additive packages that are so good at preventing sooty agglomeration fuel-dilution related deposits at lower temperatures.

I may be off beat here, but you’re recommending Dexos1 Gen 2 for this application, and I was curious about the reasoning. With Gen 3 available, it appears to be a more robust approval on paper. What are the differences, if you don't mind, between Gen 2 and Gen 3 that would make one more appropriate than the other in this case?

Thanks again for the thread, I’ve learned a lot from it.

 

[scrllock]

Curious if measuring elsewhere could potentially give a more accurate reading such as the oil filter. I have observed a vehicle with oil temperature sensor having the most accurate reading at the hottest reading on the oil filter, with the pan and other parts of the block and heads being several degrees lower

A laser thermometer is a very poor way to measure oil temperature (or determine the accuracy of a fluid temp sensor) for a lot of reasons. The accuracy of the reading really depends what you're trying to measure. Temperature pre-cooler, post-cooler?

You also need to know the path your oil takes for that motor. In mine for example, oil goes from the cooler, to the filter, then splits off to drain to the pan or to to the piston squirters. The filter sees the coolest oil in the motor, which to me doesn't seem particularly relevant to determining the actual operating temperature of the oil when it's under shear.

In my case, I would try to tee off of one of the main oil galleys (which from factory come with oil pressure switches to monitor oil pressure as accurately as possible) and install a separate fluid temp sensor if I was concerned about it. I am concerned about oil pressure, so I'm doing this right now, just with a pressure sensor.

 

[hemioiler]

@Hohn I've read this thread with interest, some of it is above my paygrade.

Two questions if you don't mind?

1) how is it possible that this much thicker SAE 40 has a 10 degree lower pour point than the other thinner oils like 5w-20 in the same formula?

2) would this oil be recommended for my mid april - mid october months where temps are all above 0C/32F

 

[Overfill]

2) would this oil be recommended for my mid april - mid october months where temps are all above 0C/32F

Dave mentioned it reaches 25W limits; it will pump down to 5F, and crank at 14F.

 

[Hohn]

@Hohn I've read this thread with interest, some of it is above my paygrade.

Two questions if you don't mind?

1) how is it possible that this much thicker SAE 40 has a 10 degree lower pour point than the other thinner oils like 5w-20 in the same formula?

2) would this oil be recommended for my mid april - mid october months where temps are all above 0C/32F

You already got a great answer for #2, and for #1 I can only offer conjecture.

There wouldn’t be any pour point depressant in a monograde, so that’s not a likely explanation.

Nexbase 3080 is the thickest GTL base oil I know of. It’s only 8cSt kv100 and a pour point of only-12C. So it would require a lot of thickening to reach up to 40 grade. And whatever is thickening is almost certainly lowering the pour point.

To me this just screams ester thickening. Something like esterex np451, which had a pour point of -60c while having a thick kv100 of 25cSt.

 

[Hohn]

This is a really thoughtful and insightful analysis. Thank you. Might inform my oil choice, as I am firmly in the short trip, multiple cold and warm starts, low oil temps camp, and I seem to have a very effective oil cooler, as even after longer trips with highway usage, my oil seems to be around 155F. I don't have an oil thermometer, but I bought a laser thermometer and crawl under the truck after I park and check the oil pan temp. (So that temp obviously isn't on the highway, but after exiting and driving through neighborhoods.)

So if you want a HPL PAO base, you'd be leaning towards a HPL Premium Plus PCMO vs, say, Supercar or Euro.

I really wish we could get a No-VII oil in the HTHS range of 4.2 or so. In theory the 10w-40 exists, but it seems like it's never available.

 

[scrllock]

So if you want a HPL PAO base, you'd be leaning towards a HPL Premium Plus PCMO vs, say, Supercar or Euro.

I really wish we could get a No-VII oil in the HTHS range of 4.2 or so. In theory the 10w-40 exists, but it seems like it's never available.

it's available, just only in 12x1 quart quantities.