Viscosity spread & VI vs shearing

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8,576
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Ohio
Fuel dilution would probably be more of an issue for short trip driving where the oil never warms up. I still wouldn't totally discount fuel dilution causing some slight loss of viscosity when VII are used. It seems B-S almost never reports fuel dilution while other oil analyzers seem to report it more often. Either way I don't think it is going to be mnuch of an issue with those two oils.
 

dparm

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Well my car is also a DD here in downtown Chicago. 300V's high TBN and TAN are supposed to be good at handling fuel dilution. The 11L sump doesn't hurt either... I'll stick with the 5w30 for this next change and get another UOA to see how it holds up versus the 5w40.
 
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Burlington, Ontario, Canada
Originally Posted By: dparm
Originally Posted By: CATERHAM
Originally Posted By: A_Harman
One thing that struck me as odd when I was looking at the Motul PDS's, was they didn't list HTHS for the 10w40 300V. I took that as meaning it is about the same as the 5w40.
It's 4.19cP and it's listed here: http://www.motul-canada.com/en/products/...o_10W40_TDS.pdf But I think that must be a misprint as it's lower than the 5W-40's 4.51cP. I always thought that was way too high for a 176 VI, KV100 13.8cSt oil. I think the 161 VI 10W-40 has the 4.51cP HTHS and the 5W-40 the 4.19cP HTHS vis'; that makes a lot more sense. If someone really wants to know, send me a gallon of each and I'll be more than happy to confirm it!
Realistically how much do you need to determine the HTHS?
The difference in HTHS values between Motul 5W-40 and 10W-40 is 0.32cP. That should represent something like a 10 psi oil pressure difference at elevated rev's if the two oils were tested in an OP equipped vehicle. Having said that, I'm certain the 300V 5W-40 has a HTHS vis no higher than 4.19cP; that's impressive enough for a KV100 13.8cSt oil.
 
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Southern NJ
The simplest method is still the best. Divide the kinematic viscosity @100C (in Cst), by the HT/HS viscosity. The lower the number the better.
 
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10,146
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Burlington, Ontario, Canada
Originally Posted By: buster
The simplest method is still the best. Divide the kinematic viscosity @100C (in Cst), by the HT/HS viscosity. The lower the number the better.
It's not a bad "blind" predictor of oil shear but simply knowing something of an oil's chemistry and VI level is still the best. For example M1 0W-40 has a shear factor of 3.55 (13.5/3.8)and the Toyota 0W-20 has a better shear factor of 3.38 (8.8/2.6). But the Toyota oil definitely shears more than the M1 oil. That's not surprising since the Toyota 0W-20 has a 214 VI and is a GP III based oil.
 
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7,933
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Michigan
Originally Posted By: CATERHAM
Originally Posted By: buster
The simplest method is still the best. Divide the kinematic viscosity @100C (in Cst), by the HT/HS viscosity. The lower the number the better.
It's not a bad "blind" predictor of oil shear but simply knowing something of an oil's chemistry and VI level is still the best. For example M1 0W-40 has a shear factor of 3.55 (13.5/3.8)and the Toyota 0W-20 has a better shear factor of 3.38 (8.8/2.6). But the Toyota oil definitely shears more than the M1 oil. That's not surprising since the Toyota 0W-20 has a 214 VI and is a GP III based oil.
I've been doing a more involved calculation to get a feel for the shear resistance of an oil: 1. Plug the KV40 and KV100 numbers into the Widman Operational Viscosity calculator, and calculate a KV150 number. 2. Take the density at 15C, and multiply by 0.9 to get an estimate for density at 150c. 3. Multiply the numbers from steps 1 and 2 to get a dynamic viscosity at 150c. 4. Divide HTHS by the DV150 number from step 3. This gives the fraction of HTHS to the expected dynamic viscosity of an oil at 150C. The higher the better. POE oils such as Redline and Motul are pretty close to 1.0.
 
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dparm

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It's in Google Docs now! https://spreadsheets.google.com/ccc?key=...uthkey=CMOmna4P You might be right about the incorrect 10w40 vs 5w40 HTHS values provided by Motul, CATERHAM. The 10w40 is technically the LEAST shear resistant of all the 300V varieties, according to A Harman's formula. BTW I threw everyone's favorite, GC, in there for grins. I had to use the estimated HTHS of 3.5 and an approximate density @ 15C of 0.88. Also threw in M1 0w40 since that's another high-quality OTS oil. Surprisingly, GC and M1 have almost the same shear resistance. Few some others in there like RLI and Redline, too.
 
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Pennsylbammyvania
Originally Posted By: dparm
Correct, group 5-rich basestocks. Nothing is shear-proof, and everyone here is a bit OCD, right? ;-)
With the various grades of 300V, I seriously doubt you have ANYTHING to worry about, even in a stressed, open tracked, boosted app. (Like Harman, if it were not sooo prohibitively priced {at ~ $5.00-$8.00/liter MORE THAN what I pay for RL!!}, I would be using it as well.) Caterham has a point about the high VIs letting you get on it sooner, but warm up can take care of this, and I would rather have a more shear stable, with a guaranteed NO ADDED VIIs, group 5 basestock for anything more than multiple 15 minute open track sessions, myself. wink
 
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10,146
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Burlington, Ontario, Canada
Actually being able to predict how an oil holds up in service is a rough guide at best; there are so many variables involved and how one oil behaves in one application may differ from another. One indisputable fact is that the higher the natural VI the better, and the best GP IV & V formulations now have natural VI's over 170 although they are expensive. But the better VII's are making there way into race oils and high performance street oils as the advantages of as high a VI as possible is undeniable. Technology doesn't stand still and I'm sure VI's over of over 200 will become increasingly more common as time marches on..
 
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10,146
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Burlington, Ontario, Canada
All the Japanese 0EM 0W-20 have 200+ VI's as does CAM II 0W-20. RL 0W-40 is close at 197, and their are a number of other 190+ VI oils such as ENEOS 0W-50 (VI 192) and RLI 0W-30 (VI 193). The good news with these modern oils is that they retain at least 90% of their virgin VI in service.
 
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Michigan
Originally Posted By: CATERHAM
If someone really wants to know, send me a gallon of each and I'll be more than happy to confirm it!
OK, I get it now, you'll run the Motul in the Caterham calibrated 4-wheel viscometer! smile (It only took me 5 days to figure it out.) Good scam to get a couple of $60 oil changes for free!
 
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43,638
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'Stralia
Originally Posted By: A_Harman
I've been doing a more involved calculation to get a feel for the shear resistance of an oil: 1. Plug the KV40 and KV100 numbers into the Widman Operational Viscosity calculator, and calculate a KV150 number. 2. Take the density at 15C, and multiply by 0.9 to get an estimate for density at 150c. 3. Multiply the numbers from steps 1 and 2 to get a dynamic viscosity at 150c. 4. Divide HTHS by the DV150 number from step 3. This gives the fraction of HTHS to the expected dynamic viscosity of an oil at 150C. The higher the better. POE oils such as Redline and Motul are pretty close to 1.0.
Quoted for the bump !!!
 
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7,933
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Michigan
Originally Posted By: Shannow
Originally Posted By: A_Harman
I've been doing a more involved calculation to get a feel for the shear resistance of an oil: 1. Plug the KV40 and KV100 numbers into the Widman Operational Viscosity calculator, and calculate a KV150 number. 2. Take the density at 15C, and multiply by 0.9 to get an estimate for density at 150c. 3. Multiply the numbers from steps 1 and 2 to get a dynamic viscosity at 150c. 4. Divide HTHS by the DV150 number from step 3. This gives the fraction of HTHS to the expected dynamic viscosity of an oil at 150C. The higher the better. POE oils such as Redline and Motul are pretty close to 1.0.
Quoted for the bump !!!
Slight change in the calculation: Use .885 instead of .90 for the density correction from 15C to 150C. This improves the density estimate slightly.
 

JAG

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Fredericksburg, VA
Here is an interesting one: Amsoil Briggs & Stratton Synthetic 4T Racing Oil https://www.amsoil.com/shop/by-product/m...-4t-racing-oil/ KV100: 11.6 KV40: 72.2 Density: 0.9059 (very dense; I think it has a lot of ester and/or PAG) HTHS: 4.2 KV150: 4.82 Density correction factor: 0.885 Harman Index: 1.02 Compare that one to the two Amsoil oils below. Amsoil Z-Rod 10W-30 https://www.amsoil.com/shop/by-product/motor-oil/gasoline/z-rod-10w-30-synthetic-motor-oil/ 11.8 74.9 0.8644 3.6 4.87 0.885 Harman Index: 0.835 Amsoil Signature Series 10W-30 https://www.amsoil.com/shop/by-product/m...etic-motor-oil/ 10.0 62.3 0.8644 3.11 4.19 0.885 Harman Index: 0.839 Viscosity calculator used: http://www.nimacltd.co.uk/viscosity-calc...wo-temperatures
 
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Paramount, California
Originally Posted By: JAG
Here is an interesting one: Amsoil Briggs & Stratton Synthetic 4T Racing Oil https://www.amsoil.com/shop/by-product/m...-4t-racing-oil/ KV100: 11.6 KV40: 72.2 Density: 0.9059 (very dense; I think it has a lot of ester and/or PAG) HTHS: 4.2 KV150: 4.82 Density correction factor: 0.885 Harman Index: 1.02 Compare that one to the two Amsoil oils below. Amsoil Z-Rod 10W-30 https://www.amsoil.com/shop/by-product/motor-oil/gasoline/z-rod-10w-30-synthetic-motor-oil/ 11.8 74.9 0.8644 3.6 4.87 0.885 Harman Index: 0.835 Amsoil Signature Series 10W-30 https://www.amsoil.com/shop/by-product/m...etic-motor-oil/ 10.0 62.3 0.8644 3.11 4.19 0.885 Harman Index: 0.839 Viscosity calculator used: http://www.nimacltd.co.uk/viscosity-calc...wo-temperatures
Correcting: A_Harman index = HTHSV / (KV150 * density @ 15 C * 0.885) (KV150 is extrapolated using the Widman operational-viscosity calculator or such. The factor 0.885 is for the density extrapolation.) Amsoil Briggs & Stratton Synthetic 4T Racing Oil A_Harman index = 1.09 (Since A_Harman index can't be greater than 1, something is obviously wrong here. Assuming that all the data is correct, the culprit would be the viscosity and/or density extrapolation to 150 C.) Amsoil Z-Rod 10W-30 A_Harman index = 0.966 Amsoil Signature Series 10W-30 A_Harman index = 0.970
 
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Paramount, California
Originally Posted By: dparm
Trying to make absolutely certain I understand this correctly. Oils with large viscosity spreads (5w50, for example) require very good basestocks and/or VIIs. And in general, those VIIs will lead to shearing under extreme conditions, such as sustained WOT. This is because the VIIs breakdown under load. Conversely, oils with small viscosity spreads (5w20, for example) do not require as good of a basestock and/or fewer VIIs. Since there is less reliance on VIIs, the oil is generally more shear stable. Correct? Trying to get clarity as the weather warms here and racing season begins for my DD. Thinking a move to 10w40 might be more prudent now, and leave the 5w30/5w40 for the winter. HTHS is a very important number for racing conditions, but shearing is still a concern. The 10w40 I am considering has a slightly lower HTHS and VI than the 5w40 (4.19 vs 4.51, and 161 vs 196, respectively), but I would assume it is much more shear stable oil and better suited to racing.
The viscosity-index improver (VII), viscosity index (VI) of the base oil, and A_Harman index are back! Below is a table for some A_Harman indexes I calculated. Note that A_Harman index only measures the temporary high-shear-viscosity loss resulting from the temporary VII shear (in high shear regions of the engine such as the bearings) and not the permanent viscosity loss from permanent VII shear and/or total VII content (unsheared + temporarily sheared + permanently sheared). In summary, PAO and GTL do best in the A_Harman index. For your racing application, I recommend Pennzoil Platinum Euro with PurePlus 5W-40. It should have a good A_Harman index and a high HTHSV. Of course, you can always upgrade to Amsoil if you like. A_Harman index = HTHSV / (KV150 * density @ 15 C * 0.885) (KV150 is extrapolated using the Widman operational-viscosity calculator or such. The factor 0.885 is for the density extrapolation.) Here is the Excel file (link) for the table.
Code:
Oil	       Density	KV40	 KV100	KV150	HTHSV	VI	DV150	A_Harman index

Delvac 15W-40 CK-4/SN	0.874	109.00	 14.10 	 5.32 	4.10		4.11	0.996
M1 AP 5W-20	        0.850	48.88	 8.20 	 3.53 	2.60	141	2.66	0.979
PPPP 10W-30	        0.841	60.50	 10.10 	 4.29 	3.10	151	3.19	0.971
M1 HM 5W-20	        0.856	50.00	 8.60 	 3.72 	2.70	150	2.82	0.958
Shell Rotella T4 15W-40	0.878	113.72	 14.84 	 5.68 	4.20		4.41	0.952
M1 EP 0W-20	        0.839	44.90	 8.60 	 3.85 	2.70	173	2.86	0.944
PPPP 5W-30 dexos1 Gen 2	0.839	53.90	 9.80 	 4.28 	3.00	170	3.18	0.944
PPPP 5W-30	        0.839	53.90	 9.80 	 4.28 	3.00	170	3.18	0.944
M1 5W-20	        0.852	49.80	 8.90 	 3.89 	2.75	160	2.93	0.938
M1 EP 5W-20	        0.850	49.60	 8.90 	 3.90 	2.75	161	2.93	0.937
Amsoil SS 5W-30	        0.855	59.70	 10.30 	 4.41 	3.11		3.34	0.932
M1 0W-20	        0.841	44.80	 8.70 	 3.91 	2.70	177	2.91	0.928
M1 HM 10W-30	        0.861	78.00	 12.10 	 4.96 	3.50		3.78	0.926
Amsoil XL 5W-30	        0.855	62.90	 11.10 	 4.77 	3.30		3.61	0.914
M1 AP 0W-20	        0.840	45.69	 8.70 	 3.89 	2.60	172	2.89	0.899
PUPPP 5W-30	        0.841	56.30	 10.30 	 4.50 	3.00	173	3.35	0.896
M1 EP 5W-30	        0.851	59.80	 10.60 	 4.57 	3.00	169	3.44	0.872
Pennzoil HM 10W-30	0.871	78.80	 11.80 	 4.79 	3.20	144	3.69	0.867
M1 FS 0W-40	        0.846	70.80	 12.90 	 5.56 	3.60	185	4.16	0.865
Rotella T6 5W-40 CJ-4	0.858	86.94	 14.09 	 5.80 	3.80		4.40	0.863
M1 5W-30	        0.855	61.70	 11.00 	 4.75 	3.10	172	3.59	0.862
M1 ESP Formula 0W-40	0.841	69.00	 12.90 	 5.61 	3.53	191	4.18	0.845
TGMO 0W-20 SN MSDS	0.851	36.10	 8.50 	 4.09 	2.60	225	3.08	0.844
M1 AP 5W-30	        0.851	67.52	 11.24 	 4.74 	3.00	160	3.57	0.840
TGMO 0W-20 SN VOA	0.851	36.16	 8.79 	 4.27 	2.60	236	3.22	0.808
M1 HM 10W-40	        0.860	107.00	 16.00 	 6.37 	3.90		4.85	0.804
M1 HM 5W-30	        0.856	72.00	 12.10 	 5.09 	3.10	151	3.86	0.804
M1 HM 5W-30	        0.856	72.00	 12.10 	 5.09 	3.10	166	3.86	0.804
 
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