Amsoil and MPG increase (I know another thread)

[XS650]

Quote:
That "shear ratio" IS the best predictor of how much the oil will shear in service, as it does correlate to the # of VI improver (how compressible the oil is).


Can you elaborate on compressibility as related to VI improver content? With numbers please.

 

[FZ1]

Dadgum,boys! I just change my "awl" every 6 months and 3600 miles so I don't have to deal with this stuff.

 

[glennc]

Originally Posted By: TeeDub
The 0w-40 will provide a fuel savings of 2%-3% in comparison to the 15w40 initially - after 100 hours in a turbo the 0w-40 will shear down by 10%-15% and so the difference will be even greater. It's tough to quantify it, but basically every 10% increase or decrease in the HT/HS viscosity yields a delta in FE of approx +/- 2% - provided the rest of the formulation chemistry is the same.

Thanks for the detailed post. Where does that information come from?

If the 10% delta in HTHS you are referring to comes with a similar delta in viscosity, then I would expect to see the 2% or so FE delta based on the viscosity alone. What needs to be determined is what happens when there is an HTHS delta without a viscosity delta. You may have answered that in part with the first quoted sentence, above, which is why I'm curious as to the source.

 

[TeeDub]

During the tapered bearing simulator test, the long chain polymers (VI modifiers) align themselves in the direction of flow as the oil passes through the test setup and then the oil "springs' back to it's original viscosity once it's no longer constrained. The analogy I like to use is running a piece of rubber though a couple of steel rollers. As it runs through the rollers the rubber is compressed, but it returns to its' original dimension as it comes out the other side. Multivis oils with polymeric thickeners behave almost exactly the same way in this test and the test has been designed to elicit this behavior.

The ratio of Vis @ 100C:HT/HS viscosity simply gives you a quantitative look at the # of polymer in a particular formulation and it's propensity to shear in service. I find it correlates very well, even for high end synthetics with high quality VI's.

There are a number of SAE papers @ http://www.SAE.org that address these relationships in the section on Ground Transportation and then Fuels & Lubricants.

The Vis @ 100C and the HT/HS viscosity @ 150C are not independent variables...for narrow range multigrades (5w-20/10w-30/15w-40/20w-50), they correlate quite well, but for wide range multigrades (0w-40/5w-50/10w-60), this correlation isn't as strong....

 

[JAG]

Originally Posted By: glennc
I don't mean to sound insulting but I am getting the impression that you are implying a level of understanding in this that you don't actually have.
Teedub may look like some oil noobie who resides in Yankee-land (LOL) but he has been around here for many years, making many more posts than his shown post-count indicates, and his technical knowledge on lubrication is first rate IMO. That may mean nothing to you but I thought I'd throw it out there anyway.

I don't know how I missed much of this thread until now. It's good.

 

[JAG]

Here's some interesting data, from an old thread, on the ratio of kinematic viscosity to HTHS viscosity that is being discussed above. jpr compiled and posted the data...though I've unquoted it so it can be read better. https://bobistheoilguy.com/forums/posts/1119808/

Originally Posted By: JAG
Originally Posted By: jpr
Independent tests results would be quite interesting, but in the meantime I don't know of any reason not to take Redline's HTHS statements at face value.

Did what I say make no sense? Calculate the ratio of KV@100C to HTHS for Redline. Do same for other straight weight oils and non-straight weight oils. Do it for other high ester content motor oils like Silkolene and Motul 300V. See how the data compares. I'd do it and post it but am too busy today. I did calculate the ratio for pure 8 cst PAO from XOM and it was 3.1. That's like a straight weight oil without any additives so the ratio is on the low end. Having VIIs makes the ratio increase because they increase kinematic viscosity more so, percent wise, than HTHS. Oils like Mobil 1 0W-40 have ratios on the high end due to high VII content.

As a note, when oils are permanently sheared, the percent change in HTHS is about 1/2 the % change in kinematic viscosity at 100C. This is from a study done in the 1980's.
Actually, I just kind of glossed over it at first - but here's some results of Kv100/HTHS based on what I've got handy at the moment. It doesn't include any straight weight or pure race oils, but I see you point about Redline sticking out:
** 10W30 **
Redline Synthetic 10w30 2.82
Mobil Mobil 1 10w30 3.18
Mobil Mobil 1 High Mileage 10w30 3.22
Shell Quaker State Peak Performance 10w30 3.28
Shell Pennzoil Multigrade 10w30 3.35
Mobil Mobil 1 Extended Performance 10w30 3.45

** 10w40 **
Redline Synthetic 10W-40 3.11
Fuchs Titan GT1 10W-40 3.38
Mobil Mobil 1 High Mileage 10W-40 3.62
Shell Pennzoil Multigrade 10W-40 3.68

** 5w30 **
Redline Synthetic 5w30 2.79
Fuchs Titan GT1 5w30 3.18
Fuchs Titan GT1 Longlife III 5w30 3.24
meguin megol Motorenol Quality 5w30 3.29
Fuchs Titan Supersyn (SL) 5w30 3.31
Castrol Syntec 5w30 3.32
Shell Pennzoil Platinum 5w30 3.32
Shell Pennzoil Platinum European Formulation Ultra 5w30 3.34
Amsoil ASL 100% Synthetic 5w30 3.34
Shell Helix Plus S 5w30 3.37
Shell Quaker State Peak Performance 5w30 3.39
Fuchs Titan Supersyn Longlife 5w30 3.4
Castrol SLX Professional LLIII Powerflow 5w30 3.4
Fuchs Titan Supersyn F 5w30 3.41
Shell Q High RPM 5w30 3.42
Shell Q European Formulation Ultra Diesel 5w30 3.43
Shell Pennzoil Platinum European Formulation Ultra Diesel 5w30 3.43
ConocoPhilips Phillips66 TropArtic Synthetic Blend 5w30 3.48
ConocoPhilips 76 Super Synthetic Blend 5w30 3.48
ConocoPhilips Conoco Syncon All Season Synthetic Blend 5w30 3.48
Shell Helix Ultra 5w30 3.49
Shell Pennzoil Multigrade 5w30 3.5
ConocoPhilips Phillips66 TropArtic Full Synthetic 5w30 3.5
ConocoPhilips 76 High Performance Full Synthetic 5w30 3.5
ConocoPhilips Conoco Syncon High Performance Synthetic 5w30 3.5
Shell Q Advanced 5w30 3.51
Shell Q Horsepower 5w30 3.51
Mobil Mobil 1 Extended Performance 5w30 3.55
ConocoPhilips 76 Super High Mileage Synthetic Blend 5w30 3.6
ConocoPhilips Kendall GT-1 High Mileage Synthetic Blend 5w30 3.6
Royal Purple Royal Purple 5w30 3.66
Mobil Mobil 1 Truck and SUV 5w30 3.66
Mobil Mobil 1 5w30 3.66
ConocoPhilips Kendall GT-1 High Performance Synthetic Blend 5w30 4.08

** 5w40 **
Redline Synthetic 5W-40 3.28
Shell Q Horsepower 5W-40 3.56
Fuchs Titan Supersyn Plus (SL PD) 5W-40 3.59
ChevronTexaco Havoline Synthetic (2) 5W-40 3.63
Mobil Mobil 1 5W-40 3.64
meguin megol Super Leichtlauf 5W-40 3.7
Amsoil AFL European Car Formula 5W-40 3.7
ChevronTexaco Havoline Synthetic 5W-40 3.71
Shell Pennzoil Platinum European Formulation 5W-40 3.72
Shell Q European Formulation 5W-40 3.72
ConocoPhilips 76 Pure Synthetic 5W-40 3.76
ConocoPhilips Kendall GT-1 Full Synthetic 5W-40 3.76
Fuchs Titan Supersyn (SL) 5W-40 3.81
ChevronTexaco Havoline Ultra 5W-40 4
Shell Helix Plus S 5W-40 4

** Others **
AMSOIL Signature Series 0w30 3.22
ChevronTexaco Havoline Synthetic 0w30 3.24
Fuchs Titan Supersyn (SL) 0w30 3.4
Shell Helix Ultra 0W-40 3.7
Mobil Mobil 1 0W-40 3.78

 

[XS650]

Originally Posted By: TeeDub
The analogy I like to use is running a piece of rubber though a couple of steel rollers. As it runs through the rollers the rubber is compressed, but it returns to its' original dimension as it comes out the other side. Multivis oils with polymeric thickeners behave almost exactly the same way in this test and the test has been designed to elicit this behavior.


You were talking spot-on technical then misused "compression", that threw me. Rubber is about as incompressible as oil, it doesn't compress, it changes shape with very little change in volume. It's Poison ratio is less than twice that of steel. But you knew that.

I will now put my pedantry aside and learn something from your posts on the topic.

 

[TeeDub]

XS650,

Would you settle for "elastically deformed"? I know we're not talking about a metallic, Hookean material but that's the frame of reference I'm most familiar with.

As for thinning out in service, it's really the superposition of the shearing forces and the localized extreme heating that causes multivis oils to degrade. This is why turbos are such good shearing machines - what suspect is happening is really more akin to catalytic cracking of the molecules and not just physically rupturing the polymer chains. Even the Bosch fuel injector test ("Kurt Orbahn test"), doesn't really simulate this combined effect, although it does tear the oil apart more than the tapered bearing simulator.

The list that JAG posted is very instructive...you can see that the general trend is that the wider the span of the oil, the higher the "shear ratio" tends to be - even Redline follows this trend. If he were to post some results with the latest petroleum 5w-20's, you'd see why they are more shear stable than a petroleum based 5w30.
This is certainly borne out in the used oil analysis I've seen for the GF-4/5w-20's....

I didn't realize you'd retired...congrads! So how's the Walmart Greeter thing working out?

 

[XS650]

Originally Posted By: TeeDub
XS650,

Would you settle for "elastically deformed"?

That's is some interesting info in your posts, thanks.

 

[buster]

Quote:
and his technical knowledge on lubrication is first rate IMO.


No doubt about it. Thanks TeeDub.