OLM and TBN

Status
Not open for further replies.
T

tig1

Joined
Jan 3, 2009
Messages
15,132
Location
Illinois
Question: How can the OLM(I don't have those on my Fords))determine the TBN left in oil? In other words, what if the OLM says run the oil for 12K, but the TBN was deleted(less than one) at 9K. As we know not all TBNs are the same. Some retain their TBN longer than others for the same miles.
 
Last edited:
Companies program OLMs based on data that they collected. They are usually very good. They consider them good enough to bet their warranty on..

They also specify what oil to use, their data is based on that oil. If you use a better oil, you could probably go longer
 
That is a great question Tig1. But I'm still leary after one answer myself. As my friend has a 2012 Chevy Colorado, I know it is filled with AC Delco Semi/Synthetic(Mobil 1). Yet his OLM shows 20% Left at 7500 miles. He has had the oil in for almost a year and he only makes 4 mile round trips to work and rarely drives it outside of work. His oil smells more like gas than it does oil. So it makes me wonder if they are something you should 100% rely on in those conditions I mentioned above.
 
I don't know that all OLMs actually measure the TBN...many of them go off a usage model that's in the ECU...so, it's kind of an estimate of remaining oil life more than a measurement...

As Vette Owner said, your oil choice might be performing much better than model...so your OLM will be off in its estimation...
 
Last edited:
Wow tig, I didn't expect a question / thread like this from you.

I doubt there's ANY machine on this earth that uses oil as lubrication, somehow samples the oil and determines oil life based on that. It's just not possible without lab equipment and we all know this so... Your question is rather silly, IMO.

Today's OLM systems determine oil life based on engine conditions that the ECU records, total engine revolutions, temps, and of course miles as well.
 
Originally Posted By: Artem
Wow tig, I didn't expect a question / thread like this from you.

I doubt there's ANY machine on this earth that uses oil as lubrication, somehow samples the oil and determines oil life based on that. It's just not possible without lab equipment and we all know this so... Your question is rather silly, IMO.

Today's OLM systems determine oil life based on engine conditions that the ECU records, total engine revolutions, temps, and of course miles as well.


Silly? No. Again, what if the TBN runs down to under 1 and the OLM says 25-35% left? Doesn't that show OLMs are prone to mis leading the driver? As you said, todays OLMs determine a lot of things, but what about TBN?
 
Last edited:
I've 'heard' that some OLM are calibrated based on the used of conventional oils and most are conservative when using synthetic.

However, some reports with DI we've seen come back with fuel dilution issues.

IMO: As long as you aren't extreme short tripping all of the time or have a known mechanical issue or contributing factor(like fuel dilution or coolant, etc), then you can trust the OLM in combination with what the service manual recommends.
 
Originally Posted By: ltslimjim


However, some reports with DI we've seen come back with fuel dilution issues.



GM changed the OLM on their V6 DI engines, reducing the OCI. This was supposedly due to timing chain wear, which could be related to fuel dilution.
 
Last edited:
Originally Posted By: tig1
Originally Posted By: Artem
Wow tig, I didn't expect a question / thread like this from you.

I doubt there's ANY machine on this earth that uses oil as lubrication, somehow samples the oil and determines oil life based on that. It's just not possible without lab equipment and we all know this so... Your question is rather silly, IMO.

Today's OLM systems determine oil life based on engine conditions that the ECU records, total engine revolutions, temps, and of course miles as well.


Silly? No. Again, what if the TBN runs down to under 1 and the OLM says 25-35% left? Doesn't that show OLMs are prone to mis leading the driver? As you said, todays OLMs determine a lot of things, but what about TBN?


Has it been proven that just because the TBN is depleted that an oil stops doing its job in lubricating an engine?

Sure the acidic contents of the oil might be going up but its still lubricating the engine.
 
Artem,

I suspect TBN may be way over played. I know one guy that uses reg M1 5-30 in his 99 Silverado and only changes oil every 15-20K. The engine has 300K and still runs great. You know the TBN has got to be near 0 at that point.Also BITOGs "FiSSKIER" has gone
up to 20K OCIs with M1 0-20 on engines with 300K. Again no engine problems. Since I only do 10K OCIs I never worry about TBN. But some people are following their OLM and doing 10-12K OCIs on conventional oil. You know the TBN has got to be deleted by then.
 
Last edited:
Good points there.

Aren't today's OLM systems (talking about 2006+) designed with OEM fluid in mind? Take my Honda Civic for example, it's basically designed to run on Honda's synthetic oil, not conventional.

Same with other vehicles who's OLM takes them up to 10k. The OEM fluid is most likely a synthetic blend, designed to go the distance.

Now when you follow the OLM but decide to use cheap conventional oil, i can see where the problem will arise.
 
We follow exact OLM intervals in an extremely heavy duty cycle, and our oldest truck in the fleet has over 400k miles on it and still works daily. No smoking, leaking, or consumption. So IMO GM's OLM is fairly accurate at recommending when to change the oil.

But they vary wildly by manufacturer. You can't make blanket statements like "Today's OLM systems determine oil life based on engine conditions that the ECU records, total engine revolutions, temps, and of course miles as well." It's not that simple. Some of them are simple mileage counters!

When you sell a lot of units there's always an exception, thus there will always be some people who are outside of the normal envelope of the OLM and it's ability to predict their need for an oil change. But for the overwhelming majority of us the GM OLM is a big help.
 
Originally Posted By: m6pwr
How do you know that BMW uses this kind of sensor?

Because dielectric oil condition sensors are mentioned in specialized BMW shop literature (TIS, WDS, etc.)
 
Originally Posted By: Quattro Pete
Originally Posted By: m6pwr
How do you know that BMW uses this kind of sensor?

Because dielectric oil condition sensors are mentioned in specialized BMW shop literature (TIS, WDS, etc.)
+1. The literature can be found on BMW owner sites. However I would say the consensus is that the OCI prescribed by BMW for their turbo engines is absurd.
 
The OLM in my '06 HHR generally starts moving at a faster rate the closer to 0% it gets. I usually get bored with my oil around 20% and end up changing it.
 
2008 Avalanche 5.3L 55,511 miles, 4628 miles on 5W-30 VWB SN/GF-5, 47% OLM remaining, TAN 2.23, TBN 1.7.

That's the only data point I have so far.
 
Originally Posted By: BMWTurboDzl
Originally Posted By: Quattro Pete
Originally Posted By: m6pwr
How do you know that BMW uses this kind of sensor?

Because dielectric oil condition sensors are mentioned in specialized BMW shop literature (TIS, WDS, etc.)
+1. The literature can be found on BMW owner sites. However I would say the consensus is that the OCI prescribed by BMW for their turbo engines is absurd.


I know that the OLM in our 09 X5 35d does not measure TBN because I am now using TBN 12.6 oil instead of the usual 6.4 stuff and the OLM showed the need for a change at the usual 10K miles. I am going to wait till ~13K and do a UOA with the change.

Charlie
 
Status
Not open for further replies.

Similar threads

3
First UOA
Replies
13
Views
480
350Rocket
L
Top-off and TBN bump
Replies
9
Views
527
dumkid
H
2013 Volvo S80 3.2, 6654 mi, Castrol Euro 5W40 A3/B4 API SP
Replies
5
Views
445
fantastic
C
What do you gain by UOA and extended drain interval?
2
Replies
21
Views
2K
4WD
racer12306
2019 Ram 1500 Classic 5.7L - HPL PCEO 5w20 - 9709 miles
Replies
11
Views
2K
Plawan
Back
Top