Use of TBN and TAN outdated?

You cannot look at just TBN or TAN. Never could. Need to consider contaminants, viscosity, oxidation fuel dilution, and TBN. Somethings like the contaminants can be filtered out with a bypass filter. But for something like TBN no easy fix except to change the oil.
 
My take on the article is With the lower sulpher fuels acidification May not be the best measure of when an oil is spent. like Donald said above, oxidation fuel dilution and I will add soot and solids from modern direct injection used to gain more power per btu of fuel unit. These can lead to the oil being spent before the acid numbers or lower TBN May indicate.
Do we understand How much fuel and soot can the oil hold in suspension before it begins to deposit those solids?
 
Why would the ph drop is it wasn't combating acid?
I think their point is that in the absence of sulfur, the TBN drops a lot slower. It would take a lot more miles or runtime for TBN to drop significantly, while in the meantime other properties of the oil may render it unsuitable for further use.
 
I think their point is that in the absence of sulfur, the TBN drops a lot slower. It would take a lot more miles or runtime for TBN to drop significantly, while in the meantime other properties of the oil may render it unsuitable for further use.

But who ever thought that TBN was the sole determining factor?
 
My take on the article is With the lower sulpher fuels acidification May not be the best measure of when an oil is spent. like Donald said above, oxidation fuel dilution and I will add soot and solids from modern direct injection used to gain more power per btu of fuel unit. These can lead to the oil being spent before the acid numbers or lower TBN May indicate.
Do we understand How much fuel and soot can the oil hold in suspension before it begins to deposit those solids?

I agree, I am curious of this too.
I think that fuel dilution is now the most common problem interrupting oil life. It tends to drive varnish formation, and there doesn't seem to be a determinate proxy for OCI regarding that issue, other than "change it early."
Much of the fuel dilution issues stem from piston rings that are already stuck due to varnish or coking, or when the engine is built with low-tension rings. The problem with "change it early" is that the low tension rings seem to let fuel in during startups and, in some cases, throughout normal driving use. If we simply use % estimated fuel as the proxy, you would be obligating yourself to change it quite more often than anyone is used to.
 
you don't need tan, tbn, etc. ... When oil gets kind of dark it's shot.
Experts like to find ways to be different like color doesn't matter. They prefer to spend $20 plus time and trip to the post office to get a uoa. But one uoa is not enough and you need to establish trend (i.e. additional $20 every every oil change) ... lol
 
you don't need tan, tbn, etc. ... When oil gets kind of dark it's shot.
Experts like to find ways to be different like color doesn't matter. They prefer to spend $20 plus time and trip to the post office to get a uoa. But one uoa is not enough and you need to establish trend (i.e. additional $20 every every oil change) ... lol

I'm guessing you've never owned a diesel LMAO!!! :ROFLMAO:
 
lol no I haven't but I have a DI which is as bad ... I've heard diesel gets dark quickly.

Btw, I think uoa with tan & tbn is $30+
 
My girlfriend's 2013 Sonata turns the oil black instantly after a change in the cold winter months or within a short time during the summer. Her parents 2011 Equinox 3.0 with direct injection still looked a dark golden brown when at 0% oil life after like 5-6k miles (despite the possible impending timing chain failure).

On my own carbureted car and 2005 Silverado LS engine with port injection I always change it when it's still a dark gold color. (looks black in the pan but fairly decent on the stick or your finger still). The olm seems to be consistent with my own feelings on oil change time (down to 0% by about 3500-4500 miles).
 
DI is not as bad. With diesel, the oil will turn dark within the first 100 miles. It doesn't mean it's shot.

If determining oil condition was as simple as looking at, the whole oil analysis industry would not exist.

I agree. I can see uoa being useful for a fleet to maximize profit and even then I assume they do a few uoa on a similar trucks to obtain a baseline oci to minimize number of oil changes ... Other than that, it's not cost effective if a uoa cost almost as much as an oil change. No?

my comments were more geared towards average Joe.
 
Other than that, it's not cost effective if a uoa cost almost as much as an oil change. No?
I don't think anyone is suggesting that an "average Joe" should do a UOA prior to every oil change. To me, it makes sense to do it once or twice, just to help you figure out a safe OCI. Once you figure this out, no need to keep doing UOAs unless your driving patterns drastically change, or you suspect some serious engine issue such as coolant contamination.

Of course, an average Joe has no idea what a UOA is, so this is purely hypothetical. :)
 
unless you have a big rig taking cases not qts analysis is a waste IMO. change oil + filter regularly as most 5 qt + filter changes with todays fake synthetics as most are is a $30 DIY
 
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