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#2624184 - 05/11/12 01:10 PM Re: 5w20 vs 5w30 [Re: dave1251]
ChadW Offline


Registered: 05/10/12
Posts: 21
Loc: Idaho
So does a 5w20 shear down?

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#2624191 - 05/11/12 01:15 PM Re: 5w20 vs 5w30 [Re: ChadW]
A_Harman Online   content


Registered: 10/01/10
Posts: 5921
Loc: Michigan
Some viscosity loss can occur if the oil has Viscosity Improvers in it, but a 5w20 will remain a 20-weight. The vast majority of 20-weight oils are in the upper third of the viscosity range and will stay in grade under use.

But if your engine calls for a 5w30 in the owner's manual, I recommend that you use 5w30.
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2001 Dodge Ram 2500 diesel
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#2624195 - 05/11/12 01:20 PM Re: 5w20 vs 5w30 [Re: ChadW]
dave1251 Offline


Registered: 07/15/05
Posts: 8040
Loc: Maricopa, AZ
Originally Posted By: ChadW
So does a 5w20 shear down?


Most of the time yes but I have not seen it shear out of the 20 viscosity range. The theory is that it take less viscosity improvers(VI) to obtain the 5W rating for a 20 viscosity versus a 30 viscosity oil. So with less VI needed to formulate a muti-grade oil i.e.(5W-20,5W-30) the oil that has less VI is less prone to shearing. This is a inherent advantage to synthetic oils that synthetic oils need less VI to obtain the desired viscosity range so therefore are a little less likely to shear and more likely to stay in grade.
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make the inside of your engine oil cap white.
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#2624196 - 05/11/12 01:20 PM Re: 5w20 vs 5w30 [Re: ChadW]
bepperb Offline


Registered: 01/10/08
Posts: 4946
Loc: Milwaukee, WI
Originally Posted By: ChadW
So does a 5w20 shear down?


Yes, but generally not out of it's acceptable range without fuel dillution.

From here you can either take a few minutes to look in the UOA section, or you can read the motor oil 101. But there's no point to asking basic questions if you haven't done either of those.
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#2624201 - 05/11/12 01:26 PM Re: 5w20 vs 5w30 [Re: Rand]
zerosoma Offline


Registered: 08/12/11
Posts: 2274
Loc: Omaha, NE
Originally Posted By: Rand
Originally Posted By: ChadW
Why do we put oil in our engines? To PROTECT it. Right? To prolong the life of the engine. ????? You don't have to be a scientist to know that. It looks like a-lot of people here are pretty vague. But some at least wing it and try to give a halfway reasonable answer.




and I hope you arent trolling because I wasted 3min typing this :P



you're a slow typer
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#2624202 - 05/11/12 01:27 PM Re: 5w20 vs 5w30 [Re: bepperb]
ChadW Offline


Registered: 05/10/12
Posts: 21
Loc: Idaho
Sorry i'm not as smart as you bepperb. On a good note, dave and a couple others have been very helpfull in my dumbness!

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#2624210 - 05/11/12 01:34 PM Re: 5w20 vs 5w30 [Re: ChadW]
dave1251 Offline


Registered: 07/15/05
Posts: 8040
Loc: Maricopa, AZ
Your welcome but there are some very knowledgeable members on here I suggest you pick their brains also. The best thing you can do is read and become more educated on the matter and if you have any doubt feel free to ask. I would not say you are dumb you were just very vague on your question and it seemed that you were a little rude. That is the problem of being on a message board it is hard to tell what your motive is.
_________________________
make the inside of your engine oil cap white.
don't use.

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#2624212 - 05/11/12 01:36 PM Re: 5w20 vs 5w30 [Re: ChadW]
bepperb Offline


Registered: 01/10/08
Posts: 4946
Loc: Milwaukee, WI
Originally Posted By: ChadW
Sorry i'm not as smart as you bepperb.


You don't have to be smart, you just have to read this:

http://www.bobistheoilguy.com/motor-oil-101/

You might think you'll get answers more quickly by asking the forum questions, but I've never seen anyone respond to a question with a multiple-chapter post filled with tables and charts.


Edited by bepperb (05/11/12 01:38 PM)
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#2624216 - 05/11/12 01:40 PM Re: 5w20 vs 5w30 [Re: ChadW]
ChadW Offline


Registered: 05/10/12
Posts: 21
Loc: Idaho
Agreed dave, that's the point of most forums, to ask q's and become more knowledgable. Not define basic words in relation to questions on specific topics.

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#2624225 - 05/11/12 01:47 PM Re: 5w20 vs 5w30 [Re: bepperb]
dave1251 Offline


Registered: 07/15/05
Posts: 8040
Loc: Maricopa, AZ
Originally Posted By: bepperb
Originally Posted By: ChadW
Sorry i'm not as smart as you bepperb.


You don't have to be smart, you just have to read this:

http://www.bobistheoilguy.com/motor-oil-101/

You might think you'll get answers more quickly by asking the forum questions, but I've never seen anyone respond to a question with a multiple-chapter post filled with tables and charts.


You know that this is my fault but I have never read or referenced Motor oil 101. I just found it to be too dull but since the good doctor wrote it I bet my bottom dollar it is full of useful information.
_________________________
make the inside of your engine oil cap white.
don't use.

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#2624239 - 05/11/12 02:08 PM Re: 5w20 vs 5w30 [Re: ChadW]
TFB1 Offline


Registered: 09/03/10
Posts: 3491
Loc: VA
These posts about shear got me wondering just how API arrived at the point spread in each grade...

20W - 5.6 to 9.2 cSt = 3.6 spread

30W - 9.3 to 12.4 cSt = 3.1 spread

40W - 12.5 to 16.2 cSt = 3.7 spread

I could see a scaled progression as weight increased but looks more like they tossed darts at the wall... Musta been a [censored] of a party...

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#2624283 - 05/11/12 02:51 PM Re: 5w20 vs 5w30 [Re: ChadW]
tommygunn Offline


Registered: 01/27/11
Posts: 3061
Loc: usa
Internet forums are for discussion. The discussions been had a thousand times before. If you wanna learn, search for it.

You're being a troll by harassing people who aren't giving you the answers you think you deserve.
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#2624330 - 05/11/12 04:03 PM Re: 5w20 vs 5w30 [Re: ChadW]
Topo Offline


Registered: 12/02/11
Posts: 672
Loc: Norwalk, Ohio
Originally Posted By: ChadW
So does a 5w20 shear down?


Typically I say no. As I looked over many used oil analysis on this site. But if you get get a hefty dose of fuel dilution anything is possible.


Edited by Topo (05/11/12 04:03 PM)
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#2624336 - 05/11/12 04:14 PM Re: 5w20 vs 5w30 [Re: ChadW]
ottotheclown Offline


Registered: 06/21/09
Posts: 2115
Loc: new york
For what this is worth after 3 or so years I find it is very rare if you can reach a conclusion on websites like this. Your question would be answered if you could. But as many times I have seen, when we get close to a answer another slant gets in. Either way: welcome
Originally Posted By: ChadW
Sorry i'm not as smart as you bepperb. On a good note, dave and a couple others have been very helpfull in my dumbness!
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#2624338 - 05/11/12 04:20 PM Re: 5w20 vs 5w30 [Re: ChadW]
DragRace Offline


Registered: 11/27/06
Posts: 2327
Loc: 1/4 Mile Track
Use whatever the owners manual says to use period.Stop worrying about things that are so small,bigger things in life to worry about.

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