Nah, in fact most of the UOA on here that exhibit a viscosity deviation do not show that the VII have sheared.
M1 0W40 In 5W30 Rated Applications ?
- Thread starter ChrisD46
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How then does a multigrade oil lose viscosity as it gets used?
Isn't this quote from this BITOG fav site true? Or is that site wrong too?
"During use, the VI improvers can sheer down and break apart, causing the viscosity of the oil to decrease. Remember, exposure to high heat is the biggest factor in causing the sheer of the viscosity-index improver."
It's a mystery. I can't tell you everything, then you wouldn't have anything to question.
Nearly every UOA on this site that shows a viscosity deviation is due to _______________ ______________.
Fill in the blank. You have 15 seconds, Bob.
Nearly every UOA on this site that shows a viscosity deviation is due to _______________ ______________.
Fill in the blank. You have 15 seconds, Bob.
OVERKILL
$100 Site Donor 2021
No, it may just mean there is some fuel dilution, which is the main cause of viscosity loss.
All oils shear. Question is how much? I did UOA on M1 0W40 VISOM and it sheared from 13.5 to 13.3 after 5k.
That is different from what you arguing and "after 500 miles it will be W30."
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- Sep 15, 2020
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You missed it, it was said by Gene K that after 500mi it knocks down a grade. I was just making reference to that.
The oil itself does not shear, it's the little plastic strings that do. And yes, how much shearing is there? Some, maybe a little, maybe a lot. All shearing of the VIM's cause grade to decline. But each grade has a range. A little in same range (grade) is no concern, but moving down into next grade might be of concern? Maybe. A 0w60 falling down to a 0w40 might be normal, there's a ton of VIM's in a 0w60 vs say a 10w40 or a 20w60.
I said "and" what Gene K said.
This is what you said:
"A 0w40 probably becomes a 5w30 in no time at all from shearing the VI's."
What is "no time?"
OVERKILL
$100 Site Donor 2021
I believe everybody participating in this discussion is already familiar with the mechanism of shear, both temporary and permanent, so no need to spell that out. The debate was focused around the claim that shear was the primarily driver of viscosity loss and the assertion that this phenomenon rapidly lead to an oil going out of grade, which has been contested.
No, not all shearing causes the grade to decline. HTHS for example is measured under high shear conditions, but the condition induces primarily temporary shear where the VII polymers flatten out and their effect on increasing viscosity is reduced. Once they exit that environment they coil back up and function as they did before.
There's a similar discussion taking place in the additives forum on viscosity loss that got more technical than this one and I suggested the use of both a visc calc as well as referencing the flash point of the oil relative to virgin to discern if fuel dilution plays a larger role than indicated. This is primarily of value when discussing Blackstone UOA's as they do not directly measure fuel dilution via GC but instead infer it from flashpoint, I assume based on a "reference" virgin value that may not align with the lubricant actually being tested.
The example I used there was my own M1 0w-40 UOA from "back in the day" from my M5 where GC was used to discern fuel content:
You can see visc is at 11.24cSt and fuel is at 5%. Virgin for this version of M1 0w-40 was I believe 13.8cSt at the time.
Using Widman's Visc calc and 0.550cSt for gasoline:
Mixing viscosities | Widman International SRL
If I plug in 95% 13.8cSt and 5% 0.550cSt I end up with a final visc of 11.55cSt.
Do I consider this accurate? No, but it shows the potential effect that fuel has on viscosity and at least somewhat aligns it with an actual GC measurement of fuel content.
My assumption is that as dilution occurs, because of course it does not happen all at once, some of the lighter fractions flash off while others remain to both reduce flashpoint and viscosity, but by less than if those lighter fractions had remained. This why 5% fuel as measured via GC does not have the same impact on FP and visc than if you were to just replace 5% of the oil with gasoline and measure those properties in a lab. This is why real world results of that level of dilution, which happen, do not have the catastrophic impact that were predicted by the figures discerned from laboratory testing.
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I've got the same vehicle as you and would love to run a 40 weight in the high performance ecoboost. The Mobil 1 0w-40, although a very good oil, does not meet Ford's "B1" spec which in all probability is specified to combat LSPI. The Mobil 0W-40 also doesn't meet SN+, which by itself doesn't meet ford's spec, but does provide LSPI protection.
I've been running Mobil's 5W-30 EP, which meets Fords spec, since my first OC. I'm considering changing to Chevron Delo XSP 5W-40 which does meet SN+ and would protect against LSPI.
Is the Ford 3.5 Ecoboost susceptible to LSPI? I would assume so, but how much is unknown. I don't think I would take the gamble on my powertrain. One thing I routinely do in my truck though, is always put the vehicle in tow/haul mode. Doing that keeps the engine at more reasonable RPM levels, instead of severely lugging the engine when it is in "normal" transmission mode. Unlike on other trucks I've owned, being in tow/haul does NOT lock out the use of the transmission overdrive gears when at highway speeds. it keeps the engine RPM around 2000 RPM in easy cruising on the rural roads around here however, rather than around 1000 RPM when the transmission is left in "normal" mode. The slightly firmer shifts are not an issue for me.
Another benefit of being in Tow/Haul, is the slightly higher RPM forces more engine coolant circulation and the engine runs at least 10 degrees cooler. (I've performed the Forscan hack to show actual coolant and transmission oil temps above the analog gauges all the time)
When I tried tow haul in the gm trucks it was only acceptable for heavy towing. It kept in much too low of a gear, especially when coasting, assuming you wanted engine braking. This was on older 4 speeds which didn't lug like the newer stuff does anyway, I was just trying to get a firmer shift to be easier on the transmission.
Yeah, I had the same issue on older Dodge/Ram trucks I've owned as well.
@OVERKILL
Few questions for you:
-1-
is fuel dilution the main contributor or the only source of lowering the FP?
-2-
Bottom line the end item cSt is cSt no matter how we got there. No?
This is the number we should be focusing on and part of the loss is due to fuel dilution and part could be due to mechanical shear.
Is that correct?
-3-
does using the FP (as oppose to GC) method to calculate fuel dilution, result in showing a lower number than actual?
If I understand this correctly, the FP method can not measure the true fuel dilution correctly and what you are saying is that calculating fuel dilution by this method, will erroneously lead you to believe that mechanical shear is a more of a contributing factor.
Is that correct?
You can just answer yes or no and I can go back and re-read the previous posts if I missed or misunderstood something.
-4-
Also how important is going for a long drive (i.e. getting the oil hot) before taking the oil sample? lets say from 1 to 10 scale.
Thanks
Few questions for you:
-1-
is fuel dilution the main contributor or the only source of lowering the FP?
-2-
Bottom line the end item cSt is cSt no matter how we got there. No?
This is the number we should be focusing on and part of the loss is due to fuel dilution and part could be due to mechanical shear.
Is that correct?
-3-
does using the FP (as oppose to GC) method to calculate fuel dilution, result in showing a lower number than actual?
If I understand this correctly, the FP method can not measure the true fuel dilution correctly and what you are saying is that calculating fuel dilution by this method, will erroneously lead you to believe that mechanical shear is a more of a contributing factor.
Is that correct?
You can just answer yes or no and I can go back and re-read the previous posts if I missed or misunderstood something.
-4-
Also how important is going for a long drive (i.e. getting the oil hot) before taking the oil sample? lets say from 1 to 10 scale.
Thanks
OVERKILL
$100 Site Donor 2021
Just the main contributor. Mechanical shear is also a factor, particularly in oils with wide spreads, but fuel is a much larger contributor because it doesn't take much to have a very significant effect.
No. If you've got mechanical shear and the flashpoint is still nice and high, then the oil hasn't been "compromised" in terms of volatility and its additive package hasn't been diluted and potentially had fractions of it flash off. So fuel dilution is worse.
The "inference" method of just using FP, which is what Blackstone uses, tends to be extremely low when compared to GC. I expect because their "reference" flashpoint is significantly lower than what virgin is for a lot of these oils.
Yes, what this does is mislead people into thinking they are experiencing significant mechanical shear when in reality, it's fuel dilution.
That's why I recommend that if somebody is experiencing significant visc loss that they should use a lab that does GC for measuring fuel dilution so that they can better understanding of what is actually taking place.
We've had guys do this in the past, where Blackstone shows like 0.5% fuel and they use another lab that uses GC and it's like 4%.
If you don't normally take long drives; if the vehicle is a short tripper, then you should not be out driving the tar out of it before your sample because then the oil sampled is NOT representative of what's been in the sump for the duration of the OCI. If you are doing a drive, just do the same length of drive you'd normally do to ensure everything is mixed.
When I change my oil, if I'm grabbing a sample, it will be done with the vehicle just driven home from work, which is my "typical" drive.
What 0w40 do you use?
OVERKILL
$100 Site Donor 2021
Just found this thread:
Blackstone Labs vs. Oil Analyzers Inc. (Amsoil)
Hello all, Discovered this site when doing some reasearch looking for UOA options. I came across a thread asking about the two and it was suggested to give both a try and compare them side by side to help make a decision, but I couldn't find somewhere that had actually been done so I gave it a...
www.bobistheoilguy.com
And another thread where another poster notes that in his experiencing using both labs Blackstone is off by 3 percentage points or more from Polaris:
Thermostat, oil temperature and fuel dilution
I've scattered a number of posts accross this forum over the last year about fuel dilution in my 2015 Honda CRV. Polaris Labs routinely reports dilution >5% despite a mostly-highway driving pattern. Discussions with my dealer and American Honda have been unproductive. But, after too much wasted...
www.bobistheoilguy.com
EP simply costs more because it's branded "EP" whilst the Euro oil is "plain" bottle, so commands the same price as regular M1, even though most of the applications that call for it are, and it is approved for, extended drain LOL
I noticed they have an EP HM now as well. I wonder why it says HM?
1) Mobil1 FS 0W40 (favorite)
2) Castrol Edge 0W40 (when #1 isn't available)
3) Pennzoil SRT 0W40 (when I can find it, some engines purr on it, while others burn it more than #1 & #2, but I still like it very much, just has to be the right application)
4) Castrol 5W40 (in the very rare occasion when first 3 listed oils aren't available)
Will try eventually:
- Amazon Basics Euro 0w40
- Amalie 0w40 & 5w50
Oil that I dearly miss: Delo XSP 5w40. That was a heck of a sleeper oil IMHO, at a good price point too (cheaper than Rotella t6 5w40/0w40), but sadly it is gone from Wal-Mart shelves.
