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Is there a slight bump up in MPG as oil shears? #4771001
05/29/18 09:34 AM
05/29/18 09:34 AM
Joined: Apr 2017
Posts: 414
Mississippi
Speak2Mountain Offline OP
Speak2Mountain  Offline OP
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Posts: 414
Mississippi
or are there other factors in play?

Re: Is there a slight bump up in MPG as oil shears? [Re: Speak2Mountain] #4771007
05/29/18 09:40 AM
05/29/18 09:40 AM
Joined: Dec 2005
Posts: 10,023
Upper Midwest
kschachn Offline
kschachn  Offline
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Posts: 10,023
Upper Midwest
When does oil shear?


1994 BMW 530i, 231K
1996 Honda Accord, 263K
1999 Toyota Sienna, 402K
2000 Toyota ECHO, 272K
Re: Is there a slight bump up in MPG as oil shears? [Re: Speak2Mountain] #4771021
05/29/18 09:58 AM
05/29/18 09:58 AM
Joined: Sep 2013
Posts: 10,534
Indiana
dlundblad Online happy
dlundblad  Online Happy
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Posts: 10,534
Indiana
Theoretically yes.

Is it measurable though?


03 Jeep WJ 4.0 200k Castrol Edge 10w40 HM Fram XG16
02 Volvo S60 2.4T 177k M1 0w40 Mahle OX149D
97 Chevy Blazer 4.3 149k Rotella T5 10w30 Supertech ST3980

Re: Is there a slight bump up in MPG as oil shears? [Re: kschachn] #4771022
05/29/18 09:59 AM
05/29/18 09:59 AM
Joined: Sep 2013
Posts: 10,534
Indiana
dlundblad Online happy
dlundblad  Online Happy
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Indiana
Originally Posted By: kschachn
When does oil shear?


Check out UOA's from EB engines. They'll shear oil from a 5w30 to a 5w20. It's the whole reason Ford back spec'd most of them to 5w30.


03 Jeep WJ 4.0 200k Castrol Edge 10w40 HM Fram XG16
02 Volvo S60 2.4T 177k M1 0w40 Mahle OX149D
97 Chevy Blazer 4.3 149k Rotella T5 10w30 Supertech ST3980

Re: Is there a slight bump up in MPG as oil shears? [Re: kschachn] #4771024
05/29/18 10:00 AM
05/29/18 10:00 AM
Joined: Oct 2014
Posts: 12,035
Idaho
CT8 Offline
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Posts: 12,035
Idaho
Originally Posted By: kschachn
When does oil shear?
Oil [mulit visc oils] shears between the moving parts as the engine is running


2015 Ford F150 2.7
2018 Ford F350 6.2
Re: Is there a slight bump up in MPG as oil shears? [Re: Speak2Mountain] #4771029
05/29/18 10:02 AM
05/29/18 10:02 AM
Joined: Aug 2008
Posts: 3,221
Where the wind comes sweepin'
Reddy45 Offline
Reddy45  Offline
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Posts: 3,221
Where the wind comes sweepin'
This came up during a recent discussion.

Oil can shear slightly with use, but as the more volatile components of oil evaporate with use, it has a thickening effect.

So the net effect is more or less 0.

Re: Is there a slight bump up in MPG as oil shears? [Re: Reddy45] #4771035
05/29/18 10:09 AM
05/29/18 10:09 AM
Joined: Sep 2013
Posts: 10,534
Indiana
dlundblad Online happy
dlundblad  Online Happy
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Indiana
Originally Posted By: Reddy45
This came up during a recent discussion.

Oil can shear slightly with use, but as the more volatile components of oil evaporate with use, it has a thickening effect.

So the net effect is more or less 0.


I didnt think of thickening.


03 Jeep WJ 4.0 200k Castrol Edge 10w40 HM Fram XG16
02 Volvo S60 2.4T 177k M1 0w40 Mahle OX149D
97 Chevy Blazer 4.3 149k Rotella T5 10w30 Supertech ST3980

Re: Is there a slight bump up in MPG as oil shears? [Re: Speak2Mountain] #4771159
05/29/18 12:27 PM
05/29/18 12:27 PM
Joined: Aug 2010
Posts: 1,083
pa
benjy Offline
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another reason to use better oils + real synthetic groups IV + V are the BEST. less shear + less viscosity improvers that get used up + thicken oils!!

Re: Is there a slight bump up in MPG as oil shears? [Re: benjy] #4771170
05/29/18 12:44 PM
05/29/18 12:44 PM
Joined: Dec 2005
Posts: 10,023
Upper Midwest
kschachn Offline
kschachn  Offline
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Posts: 10,023
Upper Midwest
An often made statement, but as far as I've seen without merit. SonofJoe has repeatedly stated that modern viscosity improvers are very stable and are highly resistant to shear degradation. Also, how would you even know if the typical Blackstone analysis that shows viscosity loss is due to shear or fuel dilution?

Originally Posted By: benjy
another reason to use better oils + real synthetic groups IV + V are the BEST. less shear + less viscosity improvers that get used up + thicken oils!!


1994 BMW 530i, 231K
1996 Honda Accord, 263K
1999 Toyota Sienna, 402K
2000 Toyota ECHO, 272K
Re: Is there a slight bump up in MPG as oil shears? [Re: Reddy45] #4771370
05/29/18 04:27 PM
05/29/18 04:27 PM
Joined: Jul 2007
Posts: 962
SACRAMENTO, CA
rrounds Offline
rrounds  Offline
Joined: Jul 2007
Posts: 962
SACRAMENTO, CA
Originally Posted By: Reddy45
This came up during a recent discussion.

Oil can shear slightly with use, but as the more volatile components of oil evaporate with use, it has a thickening effect.

So the net effect is more or less 0.

There are 100's of UOA's on here alone that show oil sheared out of grade(little or no fuel in oil) and on the motorcycle section you will find most bikes with a shared transmission get oil thats sheared out of grade in 4000 miles or less. Sometimes a lot less miles, my old R6 would only get 2500 miles on its oil before it would shear and make shifting real notchy.

ROD


'06 S2000
'00 SSEi sold at 252k miles
'08 Ford F53 V10
'13 Jeep Sahara 2 door
Re: Is there a slight bump up in MPG as oil shears? [Re: Speak2Mountain] #4771439
05/29/18 05:49 PM
05/29/18 05:49 PM
Joined: Jul 2010
Posts: 18,941
PNW
ZeeOSix Offline
ZeeOSix  Offline
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Posts: 18,941
PNW
I keep track of my oil level carefully, and always see the consumption starts low, then starts to increase after about 300~400 miles are put on the oil. All I can think is that oil is shearing down some which increases the oil consumption enough to see it.

As oil shears w/miles; shouldn't MPG bump up #4781165
06/08/18 10:52 AM
06/08/18 10:52 AM
Joined: Apr 2017
Posts: 414
Mississippi
Speak2Mountain Offline OP
Speak2Mountain  Offline OP
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Posts: 414
Mississippi
slightly bc of it being thinner

Re: As oil shears w/miles; shouldn't MPG bump up [Re: Speak2Mountain] #4781170
06/08/18 10:58 AM
06/08/18 10:58 AM
Joined: Dec 2005
Posts: 10,023
Upper Midwest
kschachn Offline
kschachn  Offline
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Posts: 10,023
Upper Midwest
Didn't get the answer you wanted the last time or??

https://www.bobistheoilguy.com/forums/ub...n_M#Post4771001


1994 BMW 530i, 231K
1996 Honda Accord, 263K
1999 Toyota Sienna, 402K
2000 Toyota ECHO, 272K
Re: As oil shears w/miles; shouldn't MPG bump up [Re: Speak2Mountain] #4781172
06/08/18 10:59 AM
06/08/18 10:59 AM
Joined: Mar 2017
Posts: 5,758
...
PimTac Offline
PimTac  Offline
Joined: Mar 2017
Posts: 5,758
...
I thought this had been asked before, didnít know it was the same poster.


2017 Mazda CX-5 GT.

Valvoline Modern Engine 0w20
Mobil 1 EP 108A
Re: As oil shears w/miles; shouldn't MPG bump up [Re: PimTac] #4781178
06/08/18 11:05 AM
06/08/18 11:05 AM
Joined: Dec 2005
Posts: 10,023
Upper Midwest
kschachn Offline
kschachn  Offline
Joined: Dec 2005
Posts: 10,023
Upper Midwest
And only a little over a week ago.


1994 BMW 530i, 231K
1996 Honda Accord, 263K
1999 Toyota Sienna, 402K
2000 Toyota ECHO, 272K
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