UOA's 2006 Dodge Sprinter, Mobil 1 0w40

[rlent]

Here's the current analysis. I'm very pleased - the wear metals are up, but all still reading at or (mostly) below Blackstone's Universal Averages for this engine type.

Fuel dilution is still the same, no water or antifreeze, insolubles remain low, viscosity is within range, and the TBN is still fairly strong, although the TAN shot up a bit. (Doug, feel free to comment if you have any thoughts on this aspect ?)

The Motor Guard bypass certainly seems to be doing it's job (viva la toilet paper !)

addguy: I'm starting to think I might be able to go to at least 60K OCI's with this setup. That would definitely make it worthwhile from a economic standpoint - eliminating from 3 to 5 oil changes (at roughly $65 per) .... to say nothing of having an engine that just might go 1M ......

 

[addyguy]

rlent,

Unfortunatly, you may almost be at the end of this oil run - you TAN and TBN are getting awfully close to one another. If TAN surpasses TBN, even if you have TBN left, the oil become acidic and starts eating the bearings, among other things. I don't know if I'd go another 10k on the oil - even with top-offs, it might not 'keep up'.

I'd drain it at 40k miles, and start over - have you given any thought to trying another oil? I'd be inclined to but amsoil PCO 15W-40 synthetic blend, and see how far it will go with by-pass and top-offs. You might have to add less, and it will most likely cost less.

 

[rlent]

Originally Posted By: addyguy
Unfortunatly, you may almost be at the end of this oil run - you TAN and TBN are getting awfully close to one another. If TAN surpasses TBN, even if you have TBN left, the oil becomes acidic and starts eating the bearings, among other things.

addguy - I'm hesitant to say much here .... as I don't know exactly who I'm talking to

..... and what your background is ...... I'm just starting to really get (somewhat) educated in terms of motor oil, filtration, and extended drains .... so take whatever I say here with a grain of salt .... as I may not really know what I'm talking about.

I've seen the above mentioned on here a few times .... I'm still reading up on TAN's .... Blackstone made the comment that they generally don't do them on engine oil ..... so far most of the professional literature I've read seems to go along with that - TAN's seem to be generally used or other oils than crankcase lube oil (with a few exceptions)

One of the problems with using them apparently is one isn't getting a complete picture with regard to acid (acid concentration vs. acid strength) as laid out in this post I ran across:

"Total Base Number (TBN) and Total Acid Number (TAN) were originally developed for quality control monitoring of new oils. However, their common use in the monitoring of used lubricants can occasionally lead to wrong conclusions. For instance, it is known that Total Acid Number provides an indication of acid concentration, but not acid strength. As such, it cannot always be relied upon to provide a dependable indication of corrosion potential of an oil."

"There is also difficulty in setting condemning limits with TAN and TBN because of characteristic differences between trending behavior of oils. To overcome these drawbacks a new pH Method is proposed that, according to test data, seems to provide an absolute measurement of the depletion of over-base additives and the true corrosive potential of used oil, independent of oil type. It also appears that the procedure is free of interferences"

and

"High operating temperatures severely stress the oil. This results in oxidation and nitration, changes in viscosity, the build up of acidic waste products and deposits on metal surfaces. TAN is generally an issue in gearbox lubricants, gas engine, gas turbine and hydraulic lubricants. It is not generally associated with engine crankcase lubricants unless they are severely contaminated."

"The singular exception may be crankcase lubricants for gas engines, where TBN can deplete very rapidly and elevated operating temperatures can generate high levels of weak organic acids."

The use of the word "gas" above, from what I have read, is not "gasoline" but "gas" as in one of the states of matter, ie. natural gas, LPG, and the like. Admittedly, the above is only a quote (with no source attribution) that I ran across with on a forum (not even particularly oil related) .... so I take it somewhat with a grain of salt .... but it does seem to jive somewhat with other stuff I've read on sites that I would believe to be reputable (as in equipment mfgr's that make equipment to test oil)

The other thing I'm looking at is Doug has mentioned that he has run until the TAN was around 8 and the TBN as low as 1 for condemnation levels .... a little bit different equipment (Class 8 trucks) than I have to be sure ...... but ........

Quote:
I don't know if I'd go another 10k on the oil - even with top-offs, it might not 'keep up'.

It might not .... but then if I hadn't run a TAN on it, I'd probably have continued to run it down until the TBN was pretty low (
Quote:
I'd drain it at 40k miles, and start over

I'm currently less than 1K miles from that number - one of the problems with trying to stretch it out - I put on miles so fast at times, that I could have another 2K to 3K miles or more, before I get the results back - and I'm Fedexing the samples in, not mailing them - and Blackstone is turning them around as soon as they get them.

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have you given any thought to trying another oil?

....... not really ...... I mean, look at my numbers using this oil ..... if it's working ..... why change ?

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I'd be inclined to but amsoil PCO 15W-40 synthetic blend, and see how far it will go with by-pass and top-offs.

Why ?

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You might have to add less

Maybe .... but understand - the amount of oil I've been adding has alot to do with how often I'm changing my bypass - when the bypass wasn't on there, I was only using maybe around a quart or so for every 15K miles, if I recall correctly.

With the bypass filter, it's usually around 1/2 quart per element change (at around every 3K miles or so - I might be able to go longer on my element changes (5K miles) - but then that will have the downside of less "refresh" to the sump.

Quote:
and it will most likely cost less

I dunno .... the Mobil 1 0w40 I'm using is costing me $5.592 per quart (before tax) ..... if I could get 20% off Amsoil's list prices published on their website that's a tad over $5.60 per quart (not including shipping or tax)

And I would have to check to confirm that it meets one of the MB specs for this engine.

I'm not trying to dispute what you are saying, just trying to wrap my head around all of this ...... on the TAN numbers I only have two data points .... I don't even know what a TAN would be on a VOA of the oil I'm using ..... the spike in the TAN number is certainly of some concern though, to be sure.

 

[Gary Allan]

I'd go another round. Your tp changes make the true mature sump a real long way out. A 4+1 sump (assuming 1 quart added per tp change) takes something like 24k to get to a mature sump w/ 3k changes - massage as needed.


One or two FCIs over isn't going to kill anything.

 

[addyguy]

rlent,

Trust me, you're talking to an amateur OUA-reader. I'm not a chemist or tribologist or scientist of any kind! Just a hobbyist you finds this interesting and is making rough recs. based on what I read here. what you posted is getting past my level, unless i take the time to read it really, really carefully.

You made a couple of good points - the M1 0W-40 IS working really well for you, so if you get a good price on it, by all means continue with it. I just thought buying in bulk from Amsoil would save you money instead of buy M1 by the quart.

My consumption comment came from the fact that 'some' have found that M1 is consumed by engines faster than other oils, and in people who switch over to Amsoil, their consumption 'often' goes down. Thought you might want to try that.

Another good point you brought up is the warranty requirements - I have no idea how long the warranty is on this rig, but if you are still w/i the warr. period, do use an oil that is MB-apporoved. Outside of the warr. I wouldn't worry as much about it - Amsoil easily exceeds the requirements, even if it is not 'official'.

I'd still change this oil batch out and start again - err on the side of caution. You got enough use out of this fill!

 

[Doug Hillary]

Hi,
rlent - Your MB engine and its lubricant are going well

The TAN is NOT an issue at this stage and you can indeed go higher - near 8! This is as long as your TBN is above say 1.5!

These are the things that you take a UOA for when you are extending OCIs - this is what it is all about - trends!!!!!

The lubricant you are using is one of the very best available at any price. The engine's Manufacturer thinks so too

 

[rlent]

addguy - I appreciate the input and your taking the time to comment.

I'd say my price on the M1 is reasonable - I've never really checked into buying Amsoil in bulk .... there might be some merit to doing so (either with Amsoil or with another brand) - my son has 8 trucks himself, and if we could standardize on an oil for all the vehicles there might some economic advantage.

On the otherhand, with me running extended drains, my oil usage is way down over what it would be if I were changing it out every 10K (or even 15K) And the actual oil consumption (as opposed to what gets lost from bypass filter changes) is well within factory guidelines for this engine - in fact it's very much on the low side:

"When the engine has passed the break-in period, oil consumption may reach 0.5% of the fuel consumption recorded in actual operating circumstances. In isolated cases and in arduous operating conditions, oil consumption may increase to 1% of the fuel consumption record in actual operating conditions."

The above consumption levels are 2 and 4 quarts of oil per 100 gallons of fuel - I use nowhere near that much.

On the warranty aspect, I'm way over it now (5 years, 100K miles) so that isn't really an issue. However it is my understanding that the way European engines, and oil for them, are developed is significantly different than here stateside. While other oils may well work to a greater or lesser degree, it is best to stick with an oil that has a specific manufacturer approval. As I understand it, M1 0w40 is the factory fill on this vehicle - as well as a number of other Mercedes vehicles. It has worked very well so far in this engine in my estimation.

I will extend at least another 10K on this fill (I'm already halfway there) and if all aspects continue to look good at the next analysis, I will probably then go (at least) another 10K beyond that. My thoughts are that I can do so relatively safely, because of how often I am sampling and testing - things shouldn't get too far out of hand.

There is a fairly significant expense involved in getting the oil analyzed every 10K or so, and the point of this (initial) exercise is to find the reasonable maximum that the oil can be safely run. Once I have determined what the reasonable maximum is, I will not be sampling the oil nearly as much - to gain a greater economic advantage from running extended drains. So I need to find out what the reasonable maximum is during the initial phase, and then I will likely pull it back a bit and reduce the length of future OCI's to provide a bit of a "safety factor".

If I can go 60K miles per drain (eliminating around 3 to 4 oil changes) it will save me roughly $350 per year. If I could go 90K miles per drain, that's roughly $525 per year. Not a huge savings perhaps, but it's real money - and every little bit helps - particularly in the current economic environment, and considering how the expedited freight market is at the moment (extremely competitive, with depressed freight rates)

 

[rlent]

Doug,

Thank you for commenting.

After my posting of the last analysis results, I later went back thru the thread and re-read your earlier comments again on TBN vs. TAN - they had sort of gone "out of sight, out of mind" ..... they did calm my nerves on the spike up in the TAN.

I will continue to observe the trends - the wear metals are trending up but still within a very good range, considering Blackstone's universal averages for this engine type, and possibly most importantly - they are not showing a progressively more rapid increase. The TBN is a down a little, but appears to me to be holding up pretty well, considering the mileage on the sump - and the fact that the amount of makeup oil I added decreased significantly between the last two samples (1.5 quarts vs. 2.25 quarts previously)

For anyone reading this, it is indeed a bit trying to say the least, using bypass filtration and extending out my drain intervals (never having done so before) on an engine whose replacement cost is around $12K (1/3 the cost of the vehicle, new), and which I hope to have last 1M miles.

To say that I worry about doing some significant damage, or pooching the engine, would be a huge understatement (it is almost constant, since it's uncharted territory for me) - but each new analysis brings reassurance and builds greater confidence.

 

[Doug Hillary]

Hi,
rlent - Few people on here have experience in extending OCIs in real terms. This is understandable considering the BITOG "audience"

One thing to remember is that wear metals are accumulative and will continue to rise until the OC point. As mentioned earlier this is one reason why I always took an oil sample then - this is a valuable datum point. Some contaminants will remain after the OC of course - how much depends on the complexity of the engine's lubrication system in this regard

Monitoring the lubricant's condition until the OC point is vital in the trending process - as is the datum point. It always stands alone in my databases

Once you decide on the acceptable OCI point based on certain criteria (Iron, Soot, Viscosity TBN-TAN etc) and if the lubricant's condition (other contaminants etc) is still OK then this of course is the upper end of the trend line to be aimed at for next time around

Experience and confidence will gradually reduce the need for a lot of interim UOAs on the way

The lubricant you are using has a high reputation as a long OCI performer

 

[addyguy]

rlent,

It sounds like you are making a careful, informed decision. And I defer completely to Doug's advice - you're very lucky to have someone with as much knowledge and experience providing advice on your situation. You won't go wrong listening to him!

I agree with what you are saying about the cost of constant oil analysis. My personal take would be you KNOW you can go 40k miles very safetly, so I'd have dumped the oil, re-filled, and done another 40k run, and ONLY sampled again at 40k. IF that one was much better, THEN I would go 50-60k on the next run and see how it looked.

I haven't done the math on my 'plan', but it 'might' cost the same as taking this to 90k, but sampling every 10-15k miles to monitor it...I dunno, it beomes confusing and a bit of a 'wash' at that point. I'd just err a little 'more' on the side of caution with the 3-year old vehicle that makes my bread and butter...know what I mean?

 

[rlent]

addguy,

Sorry not to have replied to your last post .... I let it get lost in the shuffle.

Yup - I totally know what ya mean - I have had a bit of trepidation doing this and extending out as far as I have. I've grown much more confident - because of the UOA's, and because of the amount of make up oil I've added.

That's about to change somewhat though - I'm about to add a Mann+Hummel "Spinner 25" in place of the Motor Guard and since there is no filter element to change, I expect the amount of make up oil to drop significantly - possibly by as much as half.

Consequently, I may not be able to run the sump as long (less refresh) ..... but my service interval will go up from every 3K to 5K with the Motor Guard .... to maybe every 15K or 20K miles with the Spinner.

At any rate, the UOA of my last sample follows.

 

[rlent]

Below is my most recent UOA, sampled on 4/19/09, with 47K+ on the sump. Blackstone says good for another 10K miles. (I've already put 3K on since this most recent sample was taken, that is listed on the attached report)

The amount of make up oil is not listed on this report due to my own disorganization, I have the data - I just need to gather it up - maybe this coming week. It's my sense, just based on my recollection, the amount of make up oil was not significantly different than previous intervals. I haven't calculated it, but I would guess that 45% to 50% of the original oil remains in the sump.

˙

 

[JAG]

Tin spiked from previous zeros to 4 PPM. Do you know what the outer layer of the engine's bearings are made of? I'd guess at least one type of bearings has a tin outer layer. Knowing which bearings are made of what would be very helpful.

The TBN and TAN relationship looks unfavorable and could be the cause for the Tin spike from acidic attack.

I'd dump the oil. It has had a great run!

 

[rlent]

Originally Posted By: JAG
Tin spiked from previous zeros to 4 PPM.

Yup - I noticed that ..... although there was one previous UOA where tin showed a reading of 1 (this was before I had installed the bypass filter)

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Do you know what the outer layer of the engine's bearings are made of?

I do not.

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I'd guess at least one type of bearings has a tin outer layer.

That would be my guess as well ..... seems likely.

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Knowing which bearings are made of what would be very helpful.

I'll try to find out .... but I don't know how much luck I'll have.

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The TBN and TAN relationship looks unfavorable and could be the cause for the Tin spike from acidic attack.

Yes, it could be ..... I'd be alot more concerned though if the spike was higher than 4 ppm.

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I'd dump the oil. It has had a great run!

Right ..... it's getting there isn't it ? ......

As I mentioned previously above, I'm in the process of installing a Spinner 25 centrifuge on the vehicle ..... hope to have that done mid-next week. I already have another 3K on the oil since the sample in the UOA above was pulled.

I may go ahead and get the centrifuge installed and run it for another 7K miles, then dump it, pulling a sample at drain to see what it looks like and whether it cleaned up or not, and then start over fresh at that point.

As part of the Spinner 25 install I'm planning to add a dedicated oil sampling valve. My current sampling equipment/procedure leaves something to be desired - I use a Fumoto drain valve (the one with the nipple) which is installed in the oil pan. I do take the sample when the engine has been run and is hot, and I drain out a quart of oil before taking the sample, but the nipple on the Fumoto tends to catch all the [censored] off the road - I do always clean out it out with rubbing alcohol before drawing any oil .... still .....

 

[addyguy]

TAN is over TBN, and at least one wear metal is rising fast. Acidic by-products are rising in the oil faster than the TBN can keep them in check, and it is just starting to accelerate wear.

I'd dump it, you've proved you can go a long way on this set-up, but from here, you will most likely start hurting the engine. Maybe the centrifuge will help you go longer, but I'd start over to see.

 

[rlent]

Man ...... you guys are hard ......

..... and I was really hoping that I could at least get a "It's just a particle streak ... run it out for the rest of the 10K that Blackstone recommended ... and see how it looks then ...."

Seriously though - I understand that the acidic byproducts are rising and that the overall acid level in the oil is higher ..... that's bound to happen as the add pack gets used up and the sump ages .... but we really still have have no way to know whether or not the acidity in the oil is weak or strong ....

The way I'm thinking is:

Strong acid = higher potential for damage

Weak acid = probably little to no potential for damage

I'm also thinking that it would be unusual for only a single wear metal to shoot up if acidity was the cause .... since more than a single metal is exposed to the supposedly acidic oil ....

FWIW, I talked to the lab about the TAN level on the UOA before this one ..... and discussed why it was that TAN is used more for industrial and hydraulic fluids, as opposed to TBN for motor oil in diesel engines .... and I asked at what point they would become concerned about the TAN being high ....

The answer I got was that they might not be concerned with a TAN reading of up to 10 ...... provided that the add pack was in good shape and there was still plenty of TBN showing, and the rest of the characteristics of the oil were good.

And the TBN is only marginally lower than TAN at this point ....

The reason I'm not freaking out is the following comments of Doug Hillary in this thread:

"The TAN at 1.5 is quite acceptable. I have run many engines with the OC TAN at around 7 - wear and corrosion has been most acceptable

When TAN reaches around 6 and TBN is around 2 (D4739) a change is almost mandatory in your case"

Well ..... my TBN ain't at 2 yet ...

Further thoughts ?

 

[addyguy]

You're right, there are a lot of ways to look at this, and you probably won't damage the engine at this point.

But, the counter argument becomes...just what the heck are you trying to prove? You've gone 47k on a fill of oil, longer than most do. You've gotten your value out of this oil fill.

You make your living with this truck. Are you really going to gamble that you 'may' be shortening the life of the engine to save roughly $50-60 for new oil?

I'm not trying to berate you, please understand that. But the science of this balancing act is getting over my head, so my argument boecomes 'what's the point'? However, I again defer to Doug Hillary or the lab you were talking to - they're the experts, so if you trust them, keep going.

 

[REDDOG]

rlent,

I'd be really inclined to follow Doug's advice on TAN/TBN. He's got tons of real world experience "going long" on Mobil syns. Not sure I'd pull the plug just yet. It would be great to hear his thoughts on these specific numbers, though!

I've had a few sample reports show blips of tin (in different engines) and then return to nil the very next sample so I don't think I would let a few ppm in one report startle me too badly.

Also, just thought I'd let you know a rubber vacuum cap with a 9.5 mm I.D. fits perfectly on the nipple of a Fumoto valve to keep the nipple clean between samples. I bought mine at a Napa store. They fit tight enough to stay on, but not so tight that they are a pain to remove. Then all you have to do is remove the cap, clean with alcohol as you currently do as a precaution, let air dry briefly, then sample. Hope that may help, it has worked well for me so far.

Great looking numbers by the way! I've been watching this thread with a good deal of interest, thanks for sharing.

REDDOG

 

[rlent]

addguy,

Thanks for the additional comments. Let me see if I can clarify where I'm coming from.

Originally Posted By: addyguy
You're right, there are a lot of ways to look at this, and you probably won't damage the engine at this point.

If I thought (or knew) I was going to damage anything, then of course I wouldn't do it .... of course there is always that slight amount of uncertainty .....

Heheheh ..... yeah .... it's not so much that I'm trying to "prove" anything ... certainly not to anyone on here ..... most that frequent this forum probably have far more experience than I in this area (oil, lubrication, bypass filtration, etc.) ..... I'm sure I wouldn't even know where to start ....

If anything, what I'm trying to prove, or more accurately, answer for myself, is the following question: How far can I reasonably go ?

This being done for the long-term, as once I establish the initial baseline, I'll scale back on the UOA's significantly - probably one mid-OCI, and one at the end when I dump and change. Or maybe just one at the end, depending on what I pick for an OCI .... dunno ....

The idea is to push this initial run as far as I can to find the limit ... and then I will likely scale back the OCI to incorporate a margin of safety.

I dunno if I have mentioned here or not but some acquaintances of mine have a bypass setup (OPS-1) on their straight truck (Cat C-15 engine) and they went over 100K miles on their initial OCI .... on dino oil (not synthetic) .... I suspect that may have been possible due to both the sump size and the amount of make oil they used, although I'm not sure.

Quote:
You've gone 47k on a fill of oil, longer than most do. You've gotten your value out of this oil fill.

Have I ?

Thanks for being so willing to spend my money ....

It's true that based on the OC interval I have achieved so far, I have eliminated 3 to 4 oil changes.

Quote:
You make your living with this truck.

Well .... yes ..... I'm trying to ...

If you were familiar with what is happening with regards to freight, amount of (way, way down) and freight rates (nearing a drop of at least 50% in 18 months since I started with the carrier I'm currently leased on to - most of it in the last three months) .... you might well understand better what my motivation is.

I'm having to run more miles for less money per mile .... and having to deadhead (unpaid) further to get back in the freight lanes or a good spot ..... my carrier used to offer paid empty moves after you had sat 24 hours without getting loaded ..... to move you to a better area (basically it helped cover the cost of fuel) ..... but no more ...... now you can just sit and rot .... because they ain't gonna move ya.

I have seen (smart) people see the writing on the wall early enough and throw in the towel and put their truck up on the block to get out from under it .... and others who weren't so smart have their trucks repo'ed ..... others who were just plain dumb lose the truck and everything else ..... including their homes. It's getting really ugly out here .....

How about this - you go out on the road (I have gone out for as long as three months at a time) and you get ....... one run ... per week ..... the rest of the time you just sit ... and sit ...... and sit .......

Much (but not all) of our freight is tied to the car companies - of course, you been following what has been happening there .....

All of them traditionally shut down mid-summer for a couple of weeks to change over the lines for the next model year .... it usually gets pretty slow around that time ....

Chrysler is currently shutdown ...... GM is talking about going down for 9 weeks this summer .....that's almost two months ..... and all of them did extended shutdowns at the beginning of the year .....

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Are you really going to gamble that you 'may' be shortening the life of the engine to save roughly $50-60 for new oil?

It ain't just $50 or $60 ..... I run 100K miles or more a year .... it's more like $400 to $500 per year minimum - oil only ....... figure another 6 to 7 years of life out of the vehicle (maybe more) and you are talking $2500 to $3500 dollars .... dunno about you but that's real money to me .... maybe almost enough for the downpayment on the replacement for this vehicle.

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I'm not trying to berate you, please understand that.

No worries - I totally get that you are not.

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But the science of this balancing act is getting over my head, so my argument becomes 'what's the point'?

The point is simply to answer the question I posed above, based solely on factual, objective data and science, and to avoid letting emotions rule the day.

There's plenty of emotion here on BITOG as regards oil, OCI's, etc. - and there's nothing wrong with that whatsoever - alot of it I actually find pretty funny (amusing) ..... the passion and all ......

Some people spend time here as a past time or a hobby ..... my motivation is a little different perhaps than many - I'm doing it as business .... strictly business (although I have to confess I do find monekying around with this stuff quite enjoyable)

I'm determined survive these ugly economic times, and not become a casualty ..... that's why a year ago - when a number of people I know where sitting back with their heads in warm, dark places - I was looking at everything I could do to reduce my operating costs as far as possible ....

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However, I again defer to Doug Hillary or the lab you were talking to - they're the experts, so if you trust them, keep going.

I evaluate and consider all sources of data and/or opinion - be it you, Doug, or Blackstone - and I take all of it with a greater or lesser degree of salt ...... and try to come to own my conclusions - since ultimately I'm the one that has to make the decision on when to pull the plug and fill the pan ..... or accept responsibility for the consequences if I don't.

 

[rlent]

Originally Posted By: REDDOG
I'd be really inclined to follow Doug's advice on TAN/TBN. He's got tons of real world experience "going long" on Mobil syns.

So it would seem.

Quote:
Not sure I'd pull the plug just yet.

Got it - yeah ..... think I'm gonna hold until I rack up the recommended addtional 10K on the OC (about 6K still to go) ..... unless Doug happens by and indicates it would be a bad idea for some reason. I may give Blackstone a call or drop them an email and ask them about the tin.

Hopefully I'll have the centrifuge installed by mid-next week and will get a chance to see if that does anything to improve how the sump is looking.

I think I added either another 1/2 or full quart of makeup oil since the sample was pulled for the last UOA .... which should have refreshed things at least a little bit.

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It would be great to hear his thoughts on these specific numbers, though!

Was thinkin' the same thing myself ..... since my numbers are slightly different than the specific scenario he posted earlier in the thread.

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I've had a few sample reports show blips of tin (in different engines) and then return to nil the very next sample so I don't think I would let a few ppm in one report startle me too badly.

That's very good data to know ..... one thing that crossed my mind was that despite the fact that the tin appeared to be a significant rise (from 0 ppm to 4 ppm .... kinda outta nowhere) - since I'd hitting 0 for a number of UOA's prior to the current one - the actual number was still pretty low and might be within the lab's margin of error.

IOW, the lab - any lab - is probably going to have some margin of error - have them test the same sample 4 times .... and you might well get different numbers of tin .... maybe 2 ppm, 4 ppm, 1 ppm, and 2 ppm .....

All would be within a relatively narrow range of repeatability which would be acceptable ..... but going from 0 ppm to 4 ppm tin looks a little different than going from 0 ppm to 1 ppm ....

Quote:
Also, just thought I'd let you know a rubber vacuum cap with a 9.5 mm I.D. fits perfectly on the nipple of a Fumoto valve to keep the nipple clean between samples. I bought mine at a Napa store. They fit tight enough to stay on, but not so tight that they are a pain to remove. Then all you have to do is remove the cap, clean with alcohol as you currently do as a precaution, let air dry briefly, then sample. Hope that may help, it has worked well for me so far.

Interesting - thanks ! I did actually try that with some rubber caps from Autozone .... IIRC, they were "HELP" brand ..... they didn't hold up all that well .... could have been due to being old stock (I believe Autozone is discontinuing this brand and most of what remains here locally is "leftovers") ... or possibly just due to poor quality.

Once I install the centrifuge, the Fumoto will be gone .... as the return from the centrifuge will be going back into the sump thru the drainplug hole.

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Great looking numbers by the way!

Thanks - I've been very pleased thus far, with both the bypass system and the Mobil 1 0w40.

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I've been watching this thread with a good deal of interest, thanks for sharing.

Glad you found it interesting - thanks for taking the time to follow it and comment !