How to interpret results?

[irollturbo]

I am a bit new to all of this and was looking for a bit of information on how to interpret results from used oil analysis. I have a few questions below...sorry if this has been addressed elsewhere. Just point my head in the right direction ;-)

-I assume that as miles on the oil increases, wear metals, etc will increase. For the purposes of comparison between reports, is it generally valid to normalize the numbers to a 3K oil change?
-How does a magnetic drain plug affect the numbers? Does this skew the Fe lower, or does it generally not affect what the reports see due to the very small size of the Fe particles?
-How does changing the filter after 6 months change the numbers? Will this cause the numbers to drop due to the new filter, or are the particles generally smaller than what filter catches? I assume that the make-up oil will lower the ppm numbers, since it is essentially diluting the particles.
-If a car consumes oil and make-up oil is put in, how does this change the numbers? How should this be factored into the analysis of the results?
-Can the simple act of replacing an air filter or the spark plugs drive up the Si numbers to unacceptable levels?...(since you may be dislodging dirt)
-I have been using oil analyzers. Do they normalize the results for filter change and make-up oil, or is what you get the raw number? If so then, then it is critical that they data provided by the owner be precise. Also, do they subtract out the virgin oil Si number or is what you get the raw number?

Thanks!
Ted

[ November 10, 2003, 03:02 PM: Message edited by: irollturbo ]

 

[TooSlick]

What I do is divide by the # of miles on the sample in thousands of miles. This gives you the wear rate in terms of ppm/1000 miles. I posted some info recently on "normal" wear rates for various types of wear metals.

Adding makeup oil will reduce the wear metal concentrations. Amsoil recommends changing filters after 6 months to keep the solids level of the oil, ie oxidation/nitration levels, in check.

Oil analysis companies provide just the raw data - you have to take into account the # of makeup oil and other factors, and how they will affect the results. I suggest working with an experienced oil dealer or analyst like Terry Dyson.

Tooslick
Dixie Synthetics

 

[Robbie Alexander]

quote:

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-I assume that as miles on the oil increases, wear metals, etc will increase. -*-*
Yup. You are looking for trends.
Abd when you have one, they don't IMExp. change much at one time. What you are truly looking for is a Rapid change in 1-2 things or several changes (2-3-4) over time. This is my opinion, and I am no expert. Just been my insight, and others will disagree.

-How does a magnetic drain plug --**--
dont worry.

-How does changing the filter after 6 months change the numbers? *-*-*-
I think changing the filters is a wonderful IDEA.
Others (a lot of people) will think that you need to see the true numbers of the oil... What they are missing is that there is no quest for the Holy Grail going on here or anywhere, if it is it is in their heads, Most name brand oils today are good for 3K changes. If you want more than that and want to do oil testing, then go for it. I think it's a good idea to test once and awhile, but I also think that for most oils even the SYN oils that you should FLUSH once and awhile too, perhaps more often than they will agree about.
IMO, it is never too soon to change a filter. I use to change FRAM filters by the case a month...
Sometimes three per day (hey, I'm a nut, okay), sometimes only 1 or 2 filters a day. A filter by nature wants to be changed... Yes, theres overkill, but with a few OCI's and several used oil analysis you will better get a feel for it.
If you want the best in filtration, think about a by-pass... Is it overkill for most applications, YES...


- I assume that the make-up oil will lower the ppm numbers, since it is essentially diluting the particles.
Depends on how much, but I will not in general agree with this even though most here may....
I'm not sure on this one, the trend with me is that to some extent it does, but not enough to really be worried about... My experience has been when you have problems, it doesn't matter how much oil you dump in there, it's gonna show up REAL fast.... the thing is to look at the trend and take action when you get a few bumps in the graf and you see something going up where before it was not in the numbers.


-If a car consumes oil *-*-
How much? this is the question.
Cars normal to consume oil. In fact ALL cars do. It is not possible to NOT consume oil. Some are better than others. But consumption is not a worry that you need to address unless it is outa hand. Then if it is you can do several things about it.


-Can the simple act of replacing an air filter or the spark plugs drive up the Si numbers to unacceptable levels?...(since you may be dislodging dirt)
IMO no. It is possible I guess, and sometimes it spikes a little, but no, I would not worry about doing any maintenance during an OCI... try to plan them where you can kill two birds or Bud's with one stone
( Me, well I like Import beers or the Hard stuff).


-I have been using oil analyzers. Do they normalize the results for filter change and make-up oil, or is what you get the raw number? If so then, then it is critical that they data provided by the owner be precise. Also, do they subtract out the virgin oil Si number or is what you get the raw number?

Thanks!
Ted

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This last question is very interesting. I'm not gonna respond, exactly, but let us say, that some labs do tweek the numbers... not gonna say anymore about it. But Just go with the numbers you get, and it would not hurt to get the poop from the pooper - ask them!

 

[Pablo]

None of the popular labs used here, including OAI tweek the numbers. Some are quite inaccurate, though. OAI is not one of the inaccurate labs.

 

[pinoy99]

quote:

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Originally posted by irollturbo:

-If a car consumes oil and make-up oil is put in, how does this change the numbers? How should this be factored into the analysis of the results?

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According to Blackstone, makeup oil is factored into the result BUT it really depends when the oil is added in. If the oil is added throughout the OCI cycle(which would be normal if the vehicle consumes oil anyway) the dilution is minimal but if it is added close to taking the sample, the the result would be less acurate.

 

[Spector]

Originally posted by irollturbo:
[QB]
-I assume that as miles on the oil increases, wear metals, etc will increase.

Reply:Yes, as noted above per 1000 miles is a good way to compare different reports. Additives will normally decrease as well.,

-How does changing the filter after 6 months change the numbers? Will this cause the numbers to drop due to the new filter, or are the particles generally smaller than what filter catches?

Reply:They are too small IMO to catch, the ones that would be measured in an analysis will be there regardless. Based upon my experience it makes no diff. My current test is a 12,000 mile OCI with no filter change as compared to two where I changed the filter at 6000 miles. Will see in a month or so. I guess most people on this board know my opinion, filters are pretty much worthless appendages (under normal operating conditions) similar to your appendix.

I assume that the make-up oil will lower the ppm numbers, since it is essentially diluting the particles.

Reply:Maybe, but it would have to be a huge percentage of the volume.

Also, do they subtract out the virgin oil Si number or is what you get the raw number?

Reply:None of the labs take this into account IMO. Why, because they don't know and the formulas keep changing.

 

[Robbie Alexander]

quote:

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Originally posted by Pablo:
None of the popular labs used here, including OAI tweek the numbers. Some are quite inaccurate, though. OAI is not one of the inaccurate labs.

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Yeah, how do you know?
Are you 100.00% sure?
Are you sure the labs in general don't do any tweaking at all?

 

[Patman]

quote:

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Originally posted by Robbie Alexander:

quote:

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Originally posted by Pablo:
None of the popular labs used here, including OAI tweek the numbers. Some are quite inaccurate, though. OAI is not one of the inaccurate labs.

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Yeah, how do you know?
Are you 100.00% sure?
Are you sure the labs in general don't do any tweaking at all?

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I highly doubt it. What reason would they have for doing that? They put the oil into the machine, it spits out the exact numbers and they give you that printout. Why would they make more work for themselves by playing around with those numbers? What you see is what you get.

 

[Pablo]

There are very few things I'm 100% assured of. Maybe things like: my kids will love me until they become teenagers, my boss will always be a dork, I feel better during the dark months of winter after I work out...that sort of thing...labs not tweaking are just below this, on the par with: it will rain here in the next few weeks, my old male cat will yak on the carpet, my wife will wack my head for stareing at some girl....

Oh yeah that's also why I sent a sample of the same oil to four different labs. The results were very close in most areas, one lab was pretty wacked...but nothing in the test that pointed at tweaking. All the chats we have had with Terry, and others - never has there been a mention of labs "adjusting" for anything that a user does. Find my old post or read about it at 3 mad panchos web site (synthetic shoot out)

 

[Al]

My personal opinion is that the magnetic drain plug reduces the amount of iron. My Cavalier has one and its iron values are the lowest of 5 cars I take samples on. This is too small of a sample to be valid-its mostly an opinion

 

[Patman]

quote:

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Originally posted by Al:
My personal opinion is that the magnetic drain plug reduces the amount of iron. My Cavalier has one and its iron values are the lowest of 5 cars I take samples on. This is too small of a sample to be valid-its mostly an opinion

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I asked Terry if he felt that magnetic drain plugs would lower the iron count in used oil analysis and he says he highly doubts it would make a difference. He hasn't noticed this trend in the reports he interprets.

 

[Robbie Alexander]

They put the oil into the machine, it spits out the exact numbers

Maybe! Maybe not. Are you sure Patman, that these numbers are 100.00 % Your numbers, and not any way possible to co-mingle them with any other runs? Are you sure the labs NEVER adjust the numbers they give because of "something on their end" even if this adjustment will not really affect the results, .... Is everyone sure that ALL the LABS use the EXACT proceedures to effect the results of their tests.... ? Hummmm
Terry???
Are there any labs that even though there is a good reason for it, adjust or tweek the specific results of a sample because of certain factors?