Reposting this, since it may interest some of the FWD folks. This was for my 1993 240.

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Just got back my oil analysis results. I was particularly interested in these results, since I've been running

a K&N all winter and the conditions have been exceptionally bad in terms of the dirt, grit, and salt

blowing around. My results are listed below for both this past winter w/ K&N and the previous summer

w/ a paper air filter both with Mobil 1 10W30

Winter, With K&N, 3810 miles, ~6 month drain interval

Chromium 2 ppm

Copper 4

Iron 14

Lead 12

Tin 0

Aluminum 4

Silicon (dirt) 10

Summer, With Paper air filter, 3838 miles, ~6 month interval

Chromium 1

Copper 8

Iron 10

Lead 8

Tin 0

Aluminum 2

Silicon (dirt) 13

These results show that the K&N is working well even under the most terrible conditions. In fact the dirt

score is lower! So I'm completely comfortable with the K&N. A few of the scores were a little

higher...these differences are probably not materially significant, but are probably related to the harsher

winter conditions and maybe even the different fuel mix used.

The score limits are as follows:

Chromium 10

Copper 25

Iron 250

Lead 36

Tin 20

Aluminum 20

Silicon (dirt) 18

BTW I've switched to 0W30 with this oil change.

Later,

Ted

Ted,

Where's a good place to get an oil analysis done?

My dad highly advocates them and suggested I try my dealer. What do you think of that suggestion?

Thanks,

-Dan

I'm not sure if the dealers do this or not. I used Titan. You'll need to call them up to get the specific ppm numbers as opposed to a good, borderline, fail rating once you receive the report in the mail. They are pretty quick...I've gotten my results in about a week.

-Ted

Keep in mind that the measurements are in parts per million---and the margin of error is somewhere in the vicinity of plus or minus 40%.

So a series of oil analyses will indicate trends, but a single snapshot or two can only find things way out of whack.

In any case, both reports indicate very little wear.

Maybe my coffee just hasn't kicked in yet but why do you think the air filter in itself has much of anything to do with your oils contaminates?

I'd give the air filter much less importance there, especially being that you're not comparing results between the K&N to a stock air filter.

Ahhh, sorry. I re-read it and see the air filter changes but I'm still not convinced that the air filter in itself had anything to do with it.

If any air filter's doing its job, all it's doing is keeping airborn dirt particles from entering the combustion chamber and not much of that airborn dirt could possibly get by the engines rings to contaminate the engines oil, even with no air filter. I'd suspect that other factors were involved with why your results changed.

What you say makes sense, but apparently some dirt can find its way into the oil. Check out the following (they don't explain how...)

http://www.ianr.unl.edu/pubs/farmpower/nF225.HTM

http://www.shotimes.com/SHO3oilanalysis.html

http://www.pecuniary.com/synthetics/oilanalysis.html