TBN included in an oil analysis?

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Dec 21, 2003
Phoenix, AZ USA
I've read several notes over the months that indicate that most oil-analysis labs will calculate a Total Base Number only for extra cost. I seem to remember in one case that extra cost was around the price of the basic analysis! I bought a 6-pack of analyses from OilGuard/MTM when I bought my yet-to-be-connected bypass filter. (The 6-pack was only $54 or $9 each!) I called yesterday to see if they could/would calculate a TBN; the fellow said they include a TBN calculation for all oil samples from diesel engines and would I like that done? I said yes. We'll see in a week or so, but apparently all you have to do is ask...and for only $9! BTW, I submitted my 2nd sample of M1 0W-40 (this time with only 2400 miles on it) and a sample of virgin Red Line 5W-40.
Hi, I believe that you are better off getting both TAN and TBN readings. I do this with my engines costing in excess of $A40 each This has also been made evident with the 3MP testing and the dispute over the stated TBN figures The extra cost is worth the security of both Regards
Originally posted by Doug Hillary: Hi, I believe that you are better off getting both TAN and TBN readings. Regards
You're probably correct. But we sure do worry over the little stuff, huh!?!? My Porsche is factory filled with what I used to think and many still do think is the world's best engineoil--Mobil 1. I was plenty happy with that--and still have a good inventory of M1 0W-40--until I started reading BISOG. So now I've changed to an oil, Red Line 5W-40, that's $3 a quart (= $27/change) more expensive because I think it's better than M1, and there's even controversy about that here! Also, I'll be using in our desert summers an oil viscosity, 10W-40, that's not within Porsche's recommended ranges, ALL BECAUSE OF THIS STUPID FORUM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [Wink] So I think I'll be plenty happy with the analyses from OilGuard/MTM that include TBN numbers, all for $9. [Big Grin]
Hi, Jeffrey - you are correct and one of the issues we discussed before covered many of these points Check under the Diesel UOA's for more data People get carried away with 1ppm in a UOA as an example. Others postulate over a TBN of 4.4 being too low when the engine maker states that 1 is the minimum This Forum is oft used to "push" products, and it has deteriorated because of the vast amount of "gratuitous mis-information" generated here The Forum is excellent once you learn to cut through the junk mail The M1 or Delvac 1 would do well in your Porsche like it does in mine. These are top of the world products and I have many $A40K+ engines that have done well over 1m kms on these products I still wonder about your intended use of a by-pass filter however! Regards Doug [Cheers!]
Doug, that's a thoughtful and well-stated response. I (probably-over)analyzed and agonized plenty, and all for the tiniest improvements! I've made my choices, BTW--Red Line 10W-40 in the summer 6 months and RL 5W-40 elsetime. I'm continuously surprised at the mistatement of 'facts' about oil I read here; I guess that's why I post as often as I do, not that I know much!
Originally posted by Doug Hillary: I still wonder about your intended use of a by-pass filter however! Regards Doug [Cheers!]
Wow what a memory! I still have that OilGuard bypass (BP) filter bolted onto the 'firewall' but not plumbed. The engine is so complex and difficult to get to(!), I just don't have the heart (courage?) to do it. Also, I think I'll get around to asking Porsche about it, but I believe I know what they'll say. But I don't understand your apparent dislike or apprehension about BP filters. Surely you don't believe there's something WRONG with having cleaner oil? (This reminds me of the idiotic ads of decades ago that indicated that oil filters can selectively remove the additives from oils!)
Hi Jeffery, to the contary I strongly believe in by-pass oil filters - but only the centrifuge type See under "Centrifuge By-pass filters" on here I use the MANN-HUMMEL centrifuge type (at $A1800 each)in my heavy 500hp trucks and I can state that without them the extended drain intervals I run - 100kkms - would be impossible. We gather contaminants at a rate of about 0.0025g/km with these filters and they effectively make the full flow filters redundant. Much of the contaminant load is soot, but not all of it. They are cost effective for me and I am now running one vehicle with stainless steel 30micron FF filters again to see if flow/pressure changes occur I will shortly post again in the Diesel UOA's section and it will detail the effects of a non operating centrifuge and its effect on the OCI The trucking and earth moving industries were "brought up" on the old style cartridge type by-pass filters. They were almost a requirement in the 1950's and into the 1970's and they also acted as an oil cooler by being placed in the air flow and holding about 20 litres Regardless of what is said here on this Forum "toilet roll" by-pass filters have never been seriously considered by fleet users - the centrifuge is simply a better and more efficient device They are used as OE in trucks and marine diesels and many other sophisticated applications I have extensive knowledge of the lubrication and cooling systems of Porsche V8 engines. They are simply an excellent and conservative design with a large over capacity - both in a technical and practical sense. The secret being the large capacity cooling system and sump, the thermo oil cooler and the alloy structure of the engine Porsche here where many Cayennes have been sold absolutely frown on add-on lubrication devices such as by-pass filtration. We get road surface temps here well over the 90C mark and ambient temps in the 50C region One reason to be circumspect about fitting a centrifuge is that they actually take flow from the system and sometimes the pressure/flow reduction may have a counter productive effect. On my trucks the reduction is about .5bar which is acceptable to both Detroit and I. These engines are now at about 1m kms without a problem in that regard. The oil temps in these vehicles average about 103C and reach highs of about 113C - shutdown warning commences at about 118C with auto shutdown occuring at 120C Many Porsche V8 engines have already covered 500k (miles) on either mineral or synthetic oils without rebuild Kind regards Doug [ March 06, 2004, 07:47 PM: Message edited by: Doug Hillary ]
I believe that you are better off getting both TAN and TBN readings.
Doug ..let's talk about this TAN here a minute. Now TBN is simple. You merely use (I assume) some standard acid and record the amount of it that you use to neutralize the oil sample. This tells you how much reserve "buffering" exists in the oil. Okay ..fine and good ..now there can certainly be a debate on the "rate of TBN degradation" ..but the TBN is the TBN at that point. Now TAN is a little different. Unless you are in an acid state already ...where are you going to elevate it to?? Without using the same buffering agents to bring up the Ph ..you just have an abritrary number that has nothing to do with the product as it was 'virgin" so to speak. The glossery at the main page offers very little on TAN ..while it gives decent detail on TBN since you've got a "target" of neutral. If your target is neutral for a TAN ...your oil/lubricant is already shot ...or so one could assume.
Hi Gary, refer via search to a previous thread here "TAN v TBN" I think - this issue was discussed in some depth there I use both as confirming agents and you will see some examples of this in the abovementioned thread TBN or TAN are not the over riding factors for me in analysing UOAs and if I was to live by some of the parameters promoted here I would be some hundreds of thousands of $$$$ worse off. Some people believe a UOA of 4 or so as the lower limit. I use 1 and so does Detroit Diesel and ExxonMobil! It is past "engine family" history and a great deal of user experience that always carries the day when dealing with expensive Capital Equipment! Especially when the cheques you sign are your own money!! Regards Doug [Cheers!]
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