Recent Topics
How much should I ask?
by cwilliamsws6 - 10/23/19 04:10 PM
Happy Birthday, "Wierd Al" Yankovic!
by eljefino - 10/23/19 03:49 PM
Havoline ProDS Syn 10W-30 $19.73 6-pack
by Jackson_Slugger - 10/23/19 03:02 PM
Wix Oil Filter Rating Question
by 02vito - 10/23/19 02:30 PM
Help me decide between Fram and Mobil 1
by ZiTS - 10/23/19 02:13 PM
2003 BMW E46 M3 Rotella 15w40
by Manners226 - 10/23/19 02:10 PM
Firearm solvent/oils
by HyundaiAbuser - 10/23/19 01:56 PM
Coloured wax
by Propflux01 - 10/23/19 01:36 PM
Elk Jerky
by 28oz - 10/23/19 01:15 PM
If idle is to be avoided?
by Rglossip - 10/23/19 01:01 PM
Beck Arnley Brake Pads FMSI Materials?
by jrvn - 10/23/19 12:39 PM
Aging - What the ....
by coopns - 10/23/19 12:13 PM
Chevron Supreme 5W20 Bay Area Trade/Sell
by e55amgbenz007 - 10/23/19 10:07 AM
Auto Extra 51348 Vs Napa Gold 1348
by BeerCan - 10/23/19 10:05 AM
Latest Scam Method?
by 2015_PSD - 10/23/19 09:47 AM
Medical bills from 3 year back
by stockrex - 10/23/19 09:31 AM
2019 Nissan Pathfinder CVT drain/fill.
by JTK - 10/23/19 09:19 AM
Do I need Intel RST?
by Quattro Pete - 10/23/19 08:50 AM
Newest Members
flyyamata, laoshanren, Vincenze, Alex_CB300R_ABS, TSOC
69652 Registered Users
Who's Online Now
91 registered members (Alfred_B, 2015_PSD, 2013ecof150, 53' Stude, 2K2AcuraTL, 8 invisible), 2,102 guests, and 29 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics296,393
Posts5,096,838
Members69,652
Most Online3,532
Jul 30th, 2019
Donate to BITOG
Print Thread
Hop To
Page 1 of 2 1 2
TBN #5234518 10/09/19 06:39 AM
Joined: Sep 2010
Posts: 192
B
borgward Offline OP
OP Offline
B
Joined: Sep 2010
Posts: 192
What is the significance of the TBN number in an oil report? is higher or lower better?

Re: TBN [Re: borgward] #5234542 10/09/19 07:09 AM
Joined: May 2005
Posts: 11,821
C
Char Baby Offline
Offline
C
Joined: May 2005
Posts: 11,821
Higher is better to a point. This is where the pH starts out in a motor oil.
Base is the opposite of Acid. Base raises pH and Acid lowers pH.
For example, pH of 7 is neutral as in water(H2o). So it the case of motor oil, the more acidic the oil becomes, the lower the pH becomes. I guess that around a pH of <2, the oil is becoming too acidic for aluminum.

EDIT:
Not sure that I said all of that correctly. But from my lab experience, I know what I am trying to say.

Last edited by Char Baby; 10/09/19 07:11 AM.

"Retired"
-----------------------------------

'80 Firebird FORMULA V8/4bbl-purchased "NEW"
'15 Nissan Altima 2.5 SV
'15 Honda Civic 1.8 LX
Re: TBN [Re: borgward] #5234547 10/09/19 07:13 AM
Joined: Mar 2008
Posts: 6,733
Z
ZZman Offline
Offline
Z
Joined: Mar 2008
Posts: 6,733
Higher is better as it allows the oil to resist acid build up longer. Higher isn't really that important if you don't do long oil change intervals.


2003 Mercury Grand Marquis.
2007 Hyundai Santa Fe AWD.
2005 Toyota Avalon XLS
Re: TBN [Re: borgward] #5234552 10/09/19 07:19 AM
Joined: Oct 2015
Posts: 3,200
F
FordCapriDriver Offline
Offline
F
Joined: Oct 2015
Posts: 3,200
Some say that when the TBN drops below 3 it's time to change.


1975 Ford Capri II Ghia 3000 V6 - Repsol Elite Super 20W-50
1988 Ford Escort XR3i Cabrio - Shell Rimula R4X 15W-40 HDEO

Re: TBN [Re: FordCapriDriver] #5234557 10/09/19 07:22 AM
Joined: May 2005
Posts: 11,821
C
Char Baby Offline
Offline
C
Joined: May 2005
Posts: 11,821
Originally Posted by FordCapriDriver
Some say that when the TBN drops below 3 it's time to change.




220/221.... wink


"Retired"
-----------------------------------

'80 Firebird FORMULA V8/4bbl-purchased "NEW"
'15 Nissan Altima 2.5 SV
'15 Honda Civic 1.8 LX
Re: TBN [Re: FordCapriDriver] #5234618 10/09/19 08:20 AM
Joined: Mar 2004
Posts: 22,997
D
Donald Offline
Offline
D
Joined: Mar 2004
Posts: 22,997
Originally Posted by FordCapriDriver
Some say that when the TBN drops below 3 it's time to change.



I would say between 1 and 2 you should change.

Its not linear also.


2015 Subaru Forester 2.5 engine/CVT
2015 Ford F250 w/Powerstroke
2016 Subaru Crosstrek CVT (wife's)
Re: TBN [Re: borgward] #5234639 10/09/19 08:37 AM
Joined: Sep 2010
Posts: 192
B
borgward Offline OP
OP Offline
B
Joined: Sep 2010
Posts: 192
The TBN,s were from 2.7 to 3.4. 2.7 was on 6551 oci and 3.4 was on 8988 oci. That 8988 was after taking a long road trip. wonder what TBI of new Mobil1 would be?

Re: TBN [Re: borgward] #5234641 10/09/19 08:38 AM
Joined: Oct 2015
Posts: 3,200
F
FordCapriDriver Offline
Offline
F
Joined: Oct 2015
Posts: 3,200
I personally always go for +10 TBN because i only really do around 6000 miles a year, and i have two cars so that's roughly 3000 each and i usually change at 4500 which comes out to 18 months.


1975 Ford Capri II Ghia 3000 V6 - Repsol Elite Super 20W-50
1988 Ford Escort XR3i Cabrio - Shell Rimula R4X 15W-40 HDEO

Re: TBN [Re: borgward] #5234646 10/09/19 08:41 AM
Joined: Oct 2002
Posts: 38,152
Q
Quattro Pete Offline
Offline
Q
Joined: Oct 2002
Posts: 38,152
Originally Posted by borgward
wonder what TBI of new Mobil1 would be?
Which Mobil1? Look at the VOAs we have on this site. They'll usually show you that info.


2002 530i   2015 Q5 3.0T   2018 Charger SRT
Re: TBN [Re: Char Baby] #5234689 10/09/19 09:20 AM
Joined: Mar 2013
Posts: 914
W
weasley Offline
Offline
W
Joined: Mar 2013
Posts: 914
Originally Posted by Char Baby
Higher is better to a point. This is where the pH starts out in a motor oil.
Base is the opposite of Acid. Base raises pH and Acid lowers pH.
For example, pH of 7 is neutral as in water(H2o). So it the case of motor oil, the more acidic the oil becomes, the lower the pH becomes. I guess that around a pH of <2, the oil is becoming too acidic for aluminum.

EDIT:
Not sure that I said all of that correctly. But from my lab experience, I know what I am trying to say.

Sort of in the right place, but not technically correct.

pH is a measure of acidity and alkalinity in an aqueous medium ("pH" literally means "-log10[H+]", or minus log base ten of the concentration of hydrogen ions).

Oil is not an aqueous medium so the concept of 'acid' and 'alkali' is somewhat different and can not be measured or expressed as pH. TBN is a measure of an oil's alkaline reserve, which is used to neutralise acids. High or low is not good or bad because it depends on a number of factors as to what TBN is appropriate. Diesel engine oils tend to have higher TBN as diesel engines generate more acidic species in combustion. Longer drain oils have higher TBNs simply to allow them to carry on for longer. TBN drops in use, so the higher your starting point, the longer you go until the TBN is depleted.

High TBN in a UOA isn't always a good thing - the TBN is there to do a job - neutralise acids. If the TBN stays high then it isn't doing anything, meaning either there are no acids to mop up or that the acids are present but not being mopped up by the TBN. This idea of TBN retention is all very well, so long as the TBN is actually doing what its there for.


2017 SEAT Leon 1.4 EcoTSI 150 FR Technology DSG
2018 Volvo XC60 D4
2011 KTM 990 SMT
Re: TBN [Re: weasley] #5234754 10/09/19 10:17 AM
Joined: Oct 2002
Posts: 38,152
Q
Quattro Pete Offline
Offline
Q
Joined: Oct 2002
Posts: 38,152
Originally Posted by weasley
High TBN in a UOA isn't always a good thing - the TBN is there to do a job - neutralise acids. If the TBN stays high then it isn't doing anything, meaning either there are no acids to mop up or that the acids are present but not being mopped up by the TBN.
This is why it's helpful to know TAN as well.


2002 530i   2015 Q5 3.0T   2018 Charger SRT
Re: TBN [Re: borgward] #5234805 10/09/19 11:06 AM
Joined: Oct 2017
Posts: 268
P
PiperOne Offline
Offline
P
Joined: Oct 2017
Posts: 268
^^THIS!!^^ 100% spot on.


HDEO in Diesel Engines. No spark plugs here.
Re: TBN [Re: borgward] #5234862 10/09/19 12:17 PM
Joined: Dec 2017
Posts: 2,806
J
JLTD Offline
Offline
J
Joined: Dec 2017
Posts: 2,806
Originally Posted by borgward
What is the significance of the TBN number in an oil report? is higher or lower better?


TBN = Total Base Number. As mentioned, it is the protective additives in the oil.

Too low is bad; I base my condemnation level on Blackstone's recommendation of no lower than 1.0, going conservative at 1.5. Most of my runs never reach that level.

On the UOA, compare the TBN with the starting TBN of the oil; but that is not all to look at to determine interval. Check also the viscosity to see if it has thickened or thinned out of grade. Also check for coolant, water, and insolubles, all of which tell more about your oil's condition.

I might suggest some reading of UOA threads, plenty of information there to assist in learning what you want to know.


I use the overseas manual to choose my viscosity.

Using AMSOIL

Hers: 2008 Jeep Liberty 154k, SS 5w30/Amsoil

His: 2015 4Runner 60k, SS 5w20/Amsoil

Re: TBN [Re: ZZman] #5234872 10/09/19 12:29 PM
Joined: May 2019
Posts: 2,295
M
Mad_Hatter Offline
Offline
M
Joined: May 2019
Posts: 2,295
Originally Posted by ZZman
Higher is better as it allows the oil to resist acid build up longer. Higher isn't really that important if you don't do long oil change intervals.

True having a high(er) TBN is desirable when doing long oci's but even on short oci's a high(er) TBN can be desirable. If you have excessive blow by or dilution, these can accelerate oxidation and the formation of harmful acids.

Re: TBN [Re: weasley] #5234878 10/09/19 12:35 PM
Joined: May 2019
Posts: 2,295
M
Mad_Hatter Offline
Offline
M
Joined: May 2019
Posts: 2,295
Originally Posted by weasley

High TBN in a UOA isn't always a good thing - the TBN is there to do a job - neutralise acids. If the TBN stays high then it isn't doing anything, meaning either there are no acids to mop up or that the acids are present but not being mopped up by the TBN. This idea of TBN retention is all very well, so long as the TBN is actually doing what its there for.

Indeed reserve alkalinity is important and I've personally NEVER seen a UOA where the oils reserve alkalinity didn't drop by some amount. Every engine experiences blow by on some level... it's what's in the blow by that creates acids in the crankcase. I don't see how an oils reserve alkalinity could be unaffected by this most basic of engine processes. But maybe I'm missing something..🤔

Last edited by Mad_Hatter; 10/09/19 12:35 PM.
Page 1 of 2 1 2
Previous Thread
Index
Next Thread

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