2008 Forester, 15020 Miles, Subaru 5W-30 Syn

[bluesubie]

Originally Posted By: Al
Originally Posted By: ryanm8

But what about TAN?

LOL..who cares

I think as long as UOA turn out great (the proof is in the pudding) TBN is a waste of money. But lets face it..UOAs are in many cases a waste of money. For me its entertaining to do a long haul and check the results.

Do half that interval on that oil in a DIT FXT and you might have a different opinion.

I've definitely had uoa's flagged for low TBN.

 

[WobblyElvis]

I have a UOA from Blackstone where the TBN was 1.0. Wear metals were good and Blackstone suggested it was alright to go another 1,000 miles.

I don't think TBN or wear metals tells the whole story. I went 15,000 miles on a cheap synthetic last year and again the TBN and wear metals were fine and insolubles were at %0.3. Problem was I found carbon build-up in the oil filter. It looks like wear metals, TBN and insoluble don't show the potential for sludge build-up.

The UOA with a TBN of 1.0 can be found here.
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3495924/Re:_06_GM_2.2_12,600_mi_Mixed_#Post3495924

 

[Gene K]

I have seen one each at 0.0, 0.1 and 0.3 but in reality I agree many people change early.

 

[zeng]

Originally Posted By: WobblyElvis
I don't think TBN or wear metals tells the whole story. I went 15,000 miles on a cheap synthetic last year and again the TBN and wear metals were fine and insolubles were at %0.3. Problem was I found carbon build-up in the oil filter. It looks like wear metals, TBN and insoluble don't show the potential for sludge build-up.

Carbon build up could have indicated extended oxidation and inadequacy of dispersancy properties and/or 0.3% insoluble being nearing its 'holding limit' , which in this case I suspect this oil sample was being heavily darkened black in color.
Couple with a low TNB#(unknown)......
these are pre-cursors of oils being spent ..... despite 'good' metal wear rates..

 

[Colt45ws]

That's why I moved to Polaris as they do Oxidation and Nitration in addition to TBN...
With a TBN of 2.5 and Oxidation at 28 they flagged them both with the Oxid being "Significant" and TBN being "Moderately Low". As a result they suggested I shorten my OCI or make sure it isnt overheating.
Second run came back TBN 3.8 and Oxid 22. TBN flagged as "Slightly Low" and Oxid at a "Minor" Level.

 

[Al]

Originally Posted By: Colt45ws
That's why I moved to Polaris as they do Oxidation and Nitration in addition to TBN...
With a TBN of 2.5 and Oxidation at 28 they flagged them both with the Oxid being "Significant" and TBN being "Moderately Low". As a result they suggested I shorten my OCI or make sure it isnt overheating.
Second run came back TBN 3.8 and Oxid 22. TBN flagged as "Slightly Low" and Oxid at a "Minor" Level.

One additional thing. I did the HG job at 123K on the 08. I did at least 2 10K runs PRIOR to that time. Most UOA's were 6 or 7K miles. I usually ran the SuperTech Syn. The guy that did the job indicated the engine was very clean. Not saying you are wrong but I have no evidence to back up your claims. And I do have evidence to back up mine. To each his own

 

[zeng]

Originally Posted By: Al
Originally Posted By: Colt45ws
That's why I moved to Polaris as they do Oxidation and Nitration in addition to TBN...
With a TBN of 2.5 and Oxidation at 28 they flagged them both with the Oxid being "Significant" and TBN being "Moderately Low". As a result they suggested I shorten my OCI or make sure it isnt overheating.
Second run came back TBN 3.8 and Oxid 22. TBN flagged as "Slightly Low" and Oxid at a "Minor" Level.

One additional thing. I did the HG job at 123K on the 08. I did at least 2 10K runs PRIOR to that time. Most UOA's were 6 or 7K miles. I usually ran the SuperTech Syn. The guy that did the job indicated the engine was very clean.Not saying you are wrong but I have no evidence to back up your claims. And I do have evidence to back up mine. To each his own

?? What's the relevance ?

Colt's comments is specifically about condition of oxidised used engine oils that can be followed partly through laboratory tests (basing on science)on TBN,TAN,FTIR-oxidation and Nitration #s, insoluble products concentration,viscosity increase etc.
Other easier and cost effective ways (though less sophisticated) of monitoring used oil oxidation progression includes smell , discoloration,finger touch/feel, Blotter Spot Test etc.
The various degree of oil oxidation may manifest in varnish, sludge and sediment formation, additive depletion, base oil breakdown, filter plugging, loss in foam control, acid number (AN) increase, rust formation and corrosion etc.

 

[Colt45ws]

Im confused as well.

 

[Al]

Originally Posted By: Colt45ws
Im confused as well.

Me too. My point is that TBN appears to give enough information vis-a-vis oil condition..... as the ultimate test..engine inspection confirmed a clean engine and presumably oil that was still providing its intended function. Am I missing something? I need to do additional tests that apparently are not needed?

 

[Colt45ws]

It costs me less to have the sample run with the extra tests than it does for a basic test without TBN from BlackStone.

 

[zeng]

Originally Posted By: zeng
Originally Posted By: Al
Originally Posted By: Colt45ws
That's why I moved to Polaris as they do Oxidation and Nitration in addition to TBN...
With a TBN of 2.5 and Oxidation at 28 they flagged them both with the Oxid being "Significant" and TBN being "Moderately Low". As a result they suggested I shorten my OCI or make sure it isnt overheating.
Second run came back TBN 3.8 and Oxid 22. TBN flagged as "Slightly Low" and Oxid at a "Minor" Level.

One additional thing. I did the HG job at 123K on the 08. I did at least 2 10K runs PRIOR to that time. Most UOA's were 6 or 7K miles. I usually ran the SuperTech Syn. The guy that did the job indicated the engine was very clean.Not saying you are wrong but I have no evidence to back up your claims. And I do have evidence to back up mine. To each his own

?? What's the relevance ?

Colt's comments is specifically about condition of oxidised used engine oils that can be followed partly through laboratory tests (basing on science)on TBN,TAN,FTIR-oxidation and Nitration #s, insoluble products concentration,viscosity increase etc.
Other easier and cost effective ways (though less sophisticated) of monitoring used oil oxidation progression includes smell , discoloration,finger touch/feel, Blotter Spot Test etc.
The various degree of oil oxidation may manifest in varnish, sludge and sediment formation, additive depletion, base oil breakdown, filter plugging, loss in foam control, acid number (AN) increase, rust formation and corrosion etc.

Sorry, I was responding to the statement : '.......but I have no evidence to back up your claims'

 

[Al]

Originally Posted By: zeng

I have no evidence to back up your claims'

I understand. I have my own evidence only