M1 0-40 vs. RL 5-30 Q's

[A_Harman]

Originally Posted By: Jeffs2006EvoIX
I guess what the question is to me? is this. Is using the RL 5/30 a better choice than the M1 10/30 that the OEM recommends?

Thats why I like all the opinions, reveiws and input. How do I know if the M1 shears? I do know that when I did a VOA of M1 10/30 EP that the Vis at 100C new was 10.6 when I did my first UOA on the same oil 1500 miles later, the Vis at 100C was now 9.6 so in 1500 miles is it fair to say that the M1 sheared? Or is that just normal? The lab stated "this oil sample was on par with oils with 6000 miles of use" but my oil only had 1500 miles on it? That is the original reason why I tried the RL. Its rep for not shearing. Am I wrong in making this assumption between the 2?

Jeff


I think you just answered your own question: You know from your own data that M1 10w30 sheared down 10% in 1500 miles. This is what originally set you on a search for a more shear resistant oil. You have found one in Redline 5w30. Stick with your plan to do UOA at 3000 miles, and be sure to get the KV100 value so you can monitor if the oil has sheared. You did miss an opportunity to sample at 1500 miles to get a direct comparison with M1. Once you have your own data, then you don't have to ask other people's opinion because you will know how that oil works in your engine.

 

[Bruce T]

Originally Posted By: The_Eric
Originally Posted By: Bruce T
Originally Posted By: The_Eric
...Most mechs and builders don't know squat about oil.


Great observation. Great honesty about your profession. People mistakenly think an education in mechanical matters extends to motor oil. Most mechanics have only read about oil on bottle labels and advertisements.


I've got tons to learn on this topic - as I only know a fraction of what many on this board know. The amount of knowledge I had on oil before I found this board, you could fit on the tip of a pin... I am slowly learning though and even though I do alright as a mech, there too, I have plenty to learn.

I've seen many people come and go from the shop who know nothing about lubricants, but pretend they do... I even work for one... But that's another story.


Eric, I also have a lot to learn. I've been on this site since 2004, and I still feel like a beginner. Yes, the boss who pretends to know everything about oil is never going to learn. He can't learn with a closed mind.

 

[CATERHAM]

Originally Posted By: jaj
Aw, c'mon, humour me (note the extra "u").

I'm not reading-challenged, I just disagree with you, that's all. Here's why:

1. Wear (for real, measured by mechanical engineers doing their day jobs, not UOA's) is negatively correlated with HTHS.

2. HTHS is a blending target, just like KV100. Higher than necessary, it reduces fuel economy. Lower than necessary, it allows excessive wear. The SAE and ACEA specs try to find a balance, and the balance points are the minimun HTHS specs that have become the targets that blenders shoot for every time.

For Newtonian fluids, HTHS is just KV150 and it's surprisingly high compared to what we're used to. For instance, a Group I base stock with a VI of 100 and a KV100 of 8.9 (xw-20 territory) will deliver an HTHS somewhere between 3.5 and 4 (suddenly it's an xw-40). The only reason our favorite 5w-20 doesn't deliver this kind of HTHS is that it's made with various VII's and PPD's and other gunk blended into a low viscosity base that aims it squarely at 2.6. Any higher would forfeit the coveted API Energy Conserving label.

So that's my view of the world, and it's not just based on book learning, but also on running oil pressure vs oil temperature vs RPM plots with different oils in the same engine. My results from comparo runs of TWS 10w-60, Motul 300V 5w-40 and 10w-40 and GC 0w-30 were that they all produced plots that were more or less the same at any RPM above idle. At idle, the only variable that mattered was oil temperature, actually.

So that's why, in my West Coast world, RL 5w-30 is just a "more Newtonian" 5w-30 than OTC 5w-30's; it's still a "real" 5w-30 in every respect. It pumps like one and it flows like one. However, because the blender isn't making an OTC Energy Conserving product, its more Newtonian and delivers wear protection levels rivaling most xw-40's.


Originally Posted By: CATERHAM

My Canadian friend you clearly don't yet understand the relationship between HTHS viscosity and kinematic viscosity.
A higher HTHS vis' is not "better" it just means the oil is thicker regardless of what the KV100 spec' might be.
That's why RL 5W-30 IS A 40WT oil in reality because a HTHS vis of 3.8cP is that of a 40wt oil. It's pressurized flow at all temp's is that of a 40wt oil.
In comparison to M1 0W-40 it is a heavier oil particulatly at temp's below 100C despite M1's higher kinematic viscosity spec's.
I pointed out the HTHS vs KV100 relationship to you in a recent thread on RL 5W-20 but I do it again. The following post explains why in more detail:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2001169&page=1

Wow, I know you guy's out on the left coast are often out in left field but your misunderstanding of HTHS viscosity is the most screwed up I've ever read; pure nonsense.

HTHS viscosity is simply a measure of viscosity under conditions similar to those in an operating engine at 150C.
The simple kinematic viscosity measures doesn't take the various viscosity-pressure coefficients of different oils into consideration consiquently you will have a narrow range of possible kinematic vis' values for a given HTHS vis.

Unlike the KV100 spec', HTHS vis' correlates with the oil back pressure readings that one sees on an oil pressure guage in a operating engine. Oils with the same HTHS viscosities like RL 5W-30 and M1 0W-40 have the same oil pressure at oil temp's in the vicinity of 100C. I suspect the reason for this is that the viscosity change of motor oil between 100C and 150C is virtually linear.
The main difference between M1 and RL is M1's higher VI of 185 vs only 162 of RL meaning the M1 0W-40 will not thicken as quickly as RL 5W-30 will at lower oil temp's. This will be noticeable in an operating engine with somewhat lower oil pressure on start-up with M1 vs RL which is of course indicative of a lighter or lower viscosity oil. This despite the fact that M1 has higher KV40 and KV100 spec's. So yes, M1 0W-40 has better pressurized cold flow or pumping characteristics than RL 5W-30. Most of the misunderstanding of very high VI oils (relative to their KV100 spec's) like RL 5W-30 start's with the grade on the bottle. But if one takes the time to read the printing on the back of the very same bottle, RL does explain the viscosity characteristics of their oil quite well.

RL states in laymans terms that it has "more bearing viscosity than most petroleum 10W40s" and what their referring to is HTHS viscosity. It also says that it "pumps more quickly than a petroleum 5W-30"; not better than other synthetic 5W-30s, just dino oil. The fact is ALL other GP III and GP IV based 5W-30's and 0W-30 pump better cold than RL.

RL goes on to say that it "provides a 25% lower coefficient of friction than most other synthetics and petroleums". That may account for the reason why most users (that don't have OP gauges) that use this oil in 30wt applications don't notice that the oil is in reality a grade thicker.

 

[jaj]

Originally Posted By: CATERHAM
Wow, I know you guy's out on the left coast are often out in left field but your misunderstanding of HTHS viscosity is the most screwed up I've ever read; pure nonsense.

I wonder if a carefull study of the purity of nonsense would reveal a positive correlation with longitude. Would it be zero near Greenwich and at its zenith near the Date Line?

Originally Posted By: CATERHAM
HTHS viscosity is simply a measure of viscosity under conditions similar to those in an operating engine at 150C.

On this point, we agree.

Originally Posted By: CATERHAM
consiquently you will have a narrow range of possible kinematic vis' values for a given HTHS vis.

On this point, I disagree. Motor oil is a non-Newtonian fluid, whose non-linearities are a result of additives like long-chain alkanes whose physical characteristics change with pressure as well as temperature. Blenders adjust the mix of components to deliver the KV100, KV40 and HTHS numbers as required for the application. They are targets, designed by humans and controlled by humans. They are not a manifestation of a physical law or an immutable relationship. After all, Viscosity Index is just the slope of the straight line that passes through KV40 and KV100 when they're plotted against temperature on a log-log graph. The only reason we measure HTHS at all is that it doesn't fall on the line. If it did, there'd be no reason to measure it.

Originally Posted By: CATERHAM
Unlike the KV100 spec', HTHS vis' correlates with the oil back pressure readings that one sees on an oil pressure guage in a operating engine.

That may be true, but I don't believe that there's a cause-and-effect relationship at work. My own measurements didn't support this.

Originally Posted By: CATERHAM
That may account for the reason why most users (that don't have OP gauges) that use this oil in 30wt applications don't notice that the oil is in reality a grade thicker.

It isn't a grade thicker. It has the velocity and flow characteristics of a 5w-30 under "normal" conditions and an HTHS of 3.8. It doesn't have to defy gravity to do this, it's just blended that way.

 

[Ben99GT]

D4741 vs D4683

http://books.google.com/books?id=XjTaOqE...p;q&f=false

Page 18

 

[addyguy]

The OP got rid of the car.....and proved what is often said on here.."you will most likely get rid of the car, or have something happen to it, before your choice of oil becomes an issue"

'Nuff said.

 

[Ben99GT]

Originally Posted By: addyguy
The OP got rid of the car.....and proved what is often said on here.."you will most likely get rid of the car, or have something happen to it, before your choice of oil becomes an issue"

'Nuff said.


I know, I just read through that HTHS article again and thought of this thread since the topic of tapered plug viscometer (D4741) vs. tapered bearing viscometer (D4683) was brought up.

According to the article D4741 is actually a touch more precise and shows marginally lower viscosity, though the difference is statistically insignificant.

 

[dparm]

Originally Posted By: A_Harman
Originally Posted By: Jeffs2006EvoIX
I guess what the question is to me? is this. Is using the RL 5/30 a better choice than the M1 10/30 that the OEM recommends?

Thats why I like all the opinions, reveiws and input. How do I know if the M1 shears? I do know that when I did a VOA of M1 10/30 EP that the Vis at 100C new was 10.6 when I did my first UOA on the same oil 1500 miles later, the Vis at 100C was now 9.6 so in 1500 miles is it fair to say that the M1 sheared? Or is that just normal? The lab stated "this oil sample was on par with oils with 6000 miles of use" but my oil only had 1500 miles on it? That is the original reason why I tried the RL. Its rep for not shearing. Am I wrong in making this assumption between the 2?

Jeff


I think you just answered your own question: You know from your own data that M1 10w30 sheared down 10% in 1500 miles. This is what originally set you on a search for a more shear resistant oil. You have found one in Redline 5w30. Stick with your plan to do UOA at 3000 miles, and be sure to get the KV100 value so you can monitor if the oil has sheared. You did miss an opportunity to sample at 1500 miles to get a direct comparison with M1. Once you have your own data, then you don't have to ask other people's opinion because you will know how that oil works in your engine.




I ran Motul 300V 5w40 for my last change. I had it analyzed at 2000 and 5000 (with 5000 being the change).

Here's the KV @ 100C figures:

Mfg quoted virgin: 13.32 cst
2000 miles: 12.42 cst
5000 miles: 12.59 cst

So basically it took a 6.8% hit and actually thickened slightly to within 5.5% of virgin numbers (likely because of the extra heat generated from recent race days). This is on a 4.2L 40V V8 in my Audi that gets beat on hard and sees track time.

A bit of apples-to-oranges since mine is an ester-rich race oil with a huge 10L sump, but I'd venture a guess that shear is not linear over the course of the OCI.


(FYI: I was a bit confused by the increase in viscosity figure, so Blackstone offered to re-run it at no charge.)

 

[d00df00d]

Originally Posted By: addyguy
The OP got rid of the car.....and proved what is often said on here.."you will most likely get rid of the car, or have something happen to it, before your choice of oil becomes an issue"

'Nuff said.

Fair point, well made.