Recent Topics
New Valvoline oil line - Valvoline European Vehicle!
by BurntMusic - 09/21/19 09:13 PM
Cummins 5.9: 5W 40 vs 15W 40
by ThisBigRoadTrip - 09/21/19 09:07 PM
New Fleet and Farm opening this week
by RazorsEdge - 09/21/19 09:04 PM
Ford testing new vehicles
by 97prizm - 09/21/19 08:00 PM
Any stuffed pepper lovers here?
by 53' Stude - 09/21/19 06:55 PM
Shrinking Window Tint.
by George7941 - 09/21/19 05:30 PM
Drain and refill or Cooler line flush?
by jrvn - 09/21/19 05:25 PM
Federated Auto Parts 400 at Richmond Raceway
by bdcardinal - 09/21/19 04:40 PM
Stick with OEM or try aftermarket?
by Nav45 - 09/21/19 04:25 PM
Body Shop guys, what should I expect to pay?
by dwcopple - 09/21/19 03:59 PM
What Vehicle and Trailer to Tow Tractor?
by lancerplayer - 09/21/19 03:40 PM
Garage high humidity floor wet vehicle inside.
by littleant - 09/21/19 03:34 PM
[NEW] Carquest 95515 / Fits MB GLA/CLA
by SlavaB - 09/21/19 03:23 PM
KENDALL GT-1 HIGH PERFORMANCE SYN BLEND 5W-30
by OilReport99 - 09/21/19 03:02 PM
Weekend detail
by gregk24 - 09/21/19 02:32 PM
Valvoline Premium Blue 8600 ES 15W40
by 53' Stude - 09/21/19 01:20 PM
Axle shaft seal leak?
by aquariuscsm - 09/21/19 01:14 PM
Refills for Denso Designer wipers
by mclasser - 09/21/19 12:45 PM
Newest Members
OilReport99, TungGT, ErikLeifson, Kinnes25, Bamajoe
69348 Registered Users
Who's Online Now
108 registered members (4WD, 69GTX, 53' Stude, 2015_PSD, 97prizm, 14 invisible), 1,817 guests, and 25 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics294,881
Posts5,068,584
Members69,348
Most Online3,532
Jul 30th, 2019
Donate to BITOG
Print Thread
Hop To
Page 1 of 11 1 2 11
Do you think that's "thick" oil? Think again! #4717589 04/05/18 07:48 PM
Joined: Dec 2010
Posts: 4,467
G
Gokhan Offline OP
OP Offline
G
Joined: Dec 2010
Posts: 4,467
Recently there has been concerns regarding premature timing-chair wear, which resulted in people using thicker oils. Many people think that when they use a 0W-40, they are putting in a thick oil because it's "40-grade" when it's at normal operating temperature. It turns out that it's not that simple.

This Nissan study says that timing-chair wear has to do with the base-oil viscosity, not the finished-oil viscosity, which has more to do with the amount of the viscosity-index improver (VII) polymer blended in than the base-oil viscosity. It turns out that for boundary lubrication (metal-to-metal contact), such as in the valvetrain or timing chain, finished viscosity has no effect as the VII molecules are squeezed out and only a microscopic layer of oil is present in addition to the antiwear/extreme pressure/friction modifier (AW/EP/FM) compounds.

Nissan study on wear in timing chains

This brings the question that what's the actual viscosity of the base oil rather than the VII-blended oil, which is an indicator of the oil's ability in protecting boundary- and mixed-lubrication regions (metal-to-metal or partial metal-to-metal contact). Finished, VII-blended viscosity is only an indicator of safeguard against wear in hydrodynamic region, such as the bearings.

The clue on base-oil viscosity comes from the ExxonMobil guide on synthetic-oil blending.

Here are the two rules:

(1) As a general rule, x in xW-y is an excellent indicator of base-oil viscosity. A 5W-20 base oil is a lot thicker than a 0W-20 base oil and a 10W-30 base oil is a lot thicker than a 5W-30 base oil. So, if you really need a thick oil, such as in older engines, in TGDI engines, or any engine where timing-chain or valvetrain wear is a concern, stay of from any 0W-xx or even a 5W-xx oil.

(2) Within the same xW-y group where x is a constant but y varies, such as [0W-20, 0W-30, 0W-40] or [5W-30, 5W-40}, the oil with the smallest spread -- smallest difference between y and x -- has likely the thickest base oil and the oil with the largest spread has likely the thinnest base oil. So, 0W-20 is likely to have a thicker base oil than 0W-40! In fact in my UOA comparison of 0W-20 and 0W-40, I did find out that 0W-20 produced less valvetrain wear (less iron [Fe]) than 0W-40!

To summarize the rules for getting a really thick oil: Find the oil with the largest cold number x and the smallest spread between the hot and cold numbers y - x in the SAE viscosity grade xW-y. It's more crucial for the x to be large than the y - x to be small. A 0W-40 is an awful choice for valvetrain and timing-chain wear protection, as it has the smallest x and largest y - x. 15W-40 would be an excellent choice for a thick oil, because it has a very high cold-viscosity number and a relatively small spread between hot and cold viscosities, which indicates that it actually does have a thick base oil instead of having been thickened by the VII.

Here are the examples given by ExxonMobil. Base-stock viscosities are implied in the names of the base stocks. For example 4 means 4 cSt and 45 means 4.5 cSt. These are the base-oil viscosities calculated from the base stocks and their percentages in the table (4.1 cSt, 5.8 cSt, 8.0 cSt, and 4.3 cSt base stocks, respectively):

Code:
SAE grade  Base-oil viscosity at 100 C (KV100 for the base oil)

 0W-20     5.43 cSt
 0W-30     5.16 cSt
 0W-40     5.00 cSt
 5W-30     6.80 cSt
 5W-40     6.56 cSt
 5W-50     6.67 cSt
10W-60     7.90 cSt

So, 0W-40 is the thinnest oil in terms of the base-oil viscosity!

A final note: While x in xW-y is always a good indicator of the actual base-oil viscosity, there are variations in how much the y - x spread affects the base-oil viscosity. While ExxonMobil guide indicates the conclusions here, there are other formulations possible. You are always safe with a large x if you want a thick base oil. However, you will usually have an additional assurance on base-oil thickness if you also choose a small y - x.



2020 Toyota Prius Prime XLE plug-in hybrid, 2ZR-FXE engine, ~ 0,000 mi
TGMO 0W-16 SN Japan
OEM spin-on oil filter Japan
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717600 04/05/18 07:57 PM
Joined: Mar 2010
Posts: 1,428
S
SOHCman Offline
Offline
S
Joined: Mar 2010
Posts: 1,428
This is a interesting "study" but at what point can we accept it as truth or proof?


I urge people not to wait 100K to change out the fluid in their transfer case units. -Kestas
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717610 04/05/18 08:02 PM
Joined: May 2012
Posts: 3,102
SubieRubyRoo Offline
Offline
Joined: May 2012
Posts: 3,102
So somebody needs to start making a 10W20 oil (or even 15W20), or do we just all start running monogrades again?

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717614 04/05/18 08:05 PM
Joined: Jan 2012
Posts: 5,421
H
hatt Offline
Offline
H
Joined: Jan 2012
Posts: 5,421
Looks like I was ahead of the game with my 10w-30 and 15w-30 usage.


2013 F150 5.0, Delo XLE CK-4 10W-30, Baldwin B7449
2010 Camry 2.5, PP 10W-30, Mobil1 M1C-251A
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717664 04/05/18 08:44 PM
Joined: Dec 2011
Posts: 6,594
rooflessVW Online Content
Online Content
Joined: Dec 2011
Posts: 6,594
This is exactly why I'm considering 15W-40 over 5W-40 for my next change.


"Zed's dead baby, Zed's dead."
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717667 04/05/18 08:47 PM
Joined: Dec 2006
Posts: 20,316
A
aquariuscsm Offline
Offline
A
Joined: Dec 2006
Posts: 20,316


1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Quaker State Ultimate Durability 10W30
2012 Honda Accord Coupe EX-L 2.4,auto,San Marino Red
Quaker State Ultimate Durability 5W20

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717683 04/05/18 08:57 PM
Joined: Dec 2016
Posts: 9,438
L
Linctex Offline
Offline
L
Joined: Dec 2016
Posts: 9,438
Yep, straight 30W Oil often delivers outstanding used oil analysis on this form.

Modern straight-grade oils often exhibit much better cold flow characteristics than their compadres from decades ago.

When you look at the numbers, some straight 30W oils are ACTUALLY 15W-30 or 20W-30 oil,
Even though it is labeled as a straight 30 anyway.


"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717698 04/05/18 09:04 PM
Joined: Jul 2005
Posts: 33,005
D
demarpaint Offline
Offline
D
Joined: Jul 2005
Posts: 33,005
I'll stick with 5W30.


God Bless Our Troops

Re: Do you think that's "thick" oil? Think again! [Re: Linctex] #4717699 04/05/18 09:07 PM
Joined: Mar 2015
Posts: 6,728
B
bbhero Offline
Offline
B
Joined: Mar 2015
Posts: 6,728
Really a great point Linctex. The current 30 grade oils really are much better than past ones from years ago. I bet you are right that they really are 15w30 at the end of the day.


Nissan Altima 3.5 Coupe
Cam2 Dexos1 Gen 2 5w30 Wix 57356 Oil filter
"Treat your family like your friends and treat your friends like your family."
Re: Do you think that's "thick" oil? Think again! [Re: aquariuscsm] #4717704 04/05/18 09:11 PM
Joined: May 2012
Posts: 3,102
SubieRubyRoo Offline
Offline
Joined: May 2012
Posts: 3,102
Originally Posted By: aquariuscsm


I was interested... until I saw a 108 VI, 10% NOACK, and a 62.3 viscosity at 100*F. That, and only an API SF rating. Oh well.

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717708 04/05/18 09:17 PM
Joined: Mar 2015
Posts: 226
C
Carbon12 Offline
Offline
C
Joined: Mar 2015
Posts: 226
Thanks for posting. Counter intuitive but makes a lot of sense after thinking about it. Also thought it was interesting the study confirmed the anti-wear properties of MoDTC which I think this is the first time I seen anything other than just speculation regarding its anti wear properties.

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717710 04/05/18 09:19 PM
Joined: Mar 2016
Posts: 1,719
P
PeterPolyol Offline
Offline
P
Joined: Mar 2016
Posts: 1,719
Yes, that's what I'm talkin' about. Nice find Gokh's
It's always reasonable to assume that a benefit in one parameter might come at a cost in another parameter, even if one doesn't know what the catch is yet. Chasing inappropriately low W ratings on high-VI oils, this study would suggest, may unnecessarily increase actual component wear. Love those straight blends thumbsup

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717711 04/05/18 09:22 PM
Joined: Oct 2005
Posts: 5,292
J
JAG Offline
Offline
J
Joined: Oct 2005
Posts: 5,292
Thanks Gokhan. As you know, the “Harman Index” is a great way to quantify how close to Newtonian oils are...an indication of how much VII is used.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3630984/Harman_Index_for_0W20s....
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4406955/1

The downside is that it requires density, which some data sheets don’t provide. If it doesn’t, another good metric is ratio of HTHS to KV100. Multiply by 10 if you prefer numbers over 1 for readability reasons. It is not as good of a metric because oils of very low or high density get skewed values because kinematic viscosity is itself skewed by density. Dynamic viscosity is the “real” viscosity at low shear rates, while kinematic viscosity is not.

Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717715 04/05/18 09:26 PM
Joined: Jul 2005
Posts: 12,275
dave1251 Offline
Offline
Joined: Jul 2005
Posts: 12,275
I will continue to use 5W/10W30's.


make the inside of your engine oil cap white.
don't use.
Re: Do you think that's "thick" oil? Think again! [Re: Gokhan] #4717718 04/05/18 09:29 PM
Joined: Feb 2014
Posts: 3,385
Marco620 Offline
Offline
Joined: Feb 2014
Posts: 3,385
So, Im doing right by running 0w20 in my Honda? Good I got like 100 qts of PUP.


15' Civic 1.8 i-vtec 273,000 mi Redline 0w20, BP CVT Fluid, Archoil9100, Si-1
Doberman Whisperer!
Redline Oil,Honda,Doberman,CZ & SONY Aficionado

Page 1 of 11 1 2 11
Previous Thread
Index
Next Thread

BOB IS THE OIL GUY® Powered by UBB.threads™