I recently had the 25k service done and had Blackstone do an oil analysis. My first two changes were done at 6 & 13k miles, but this one I let go to just over 24k. I let the interval slip on purpose to just under 12k miles to see if that was OK. I use Mobil 0-40 as I get free oil/filter changes and that is what the dealer puts in.

This is what Blackstone said:

"Universal averages show typical wear for this type engine after 8,000 miles. Your oil use was 12,000 miles. We found all wear readings above average levels. That is because your engine is still in break in stage. Consequently, 12k changes are too long for the time being. No fuel, water, or coolant was found in the oil but soot was present in the sample The oil's viscosity was normal. The TBN was strong at 5.9-1.0 is low. We suggest changing your oil at 8k miles until metals reach average levels".


So, not being a gear head and not wanting to take the time to post all the metal ppms, here is my take on what they said:

1. 12 K changes are too long for the time being
2. Shorter changes will eliminate metals problem
3. 12k does not cause a problem with viscosity
4. All the huffing and puffing you hear on this site regarding what a problem 0-40 is seems to be a whole lotta, well lets just say oil sludge.

did youo change the filter? That may help everything.

_________________
Ryan
2006 Ford F-250 PSD CC FX4
**GONE**
2005 Jeep Liberty CRD
SAMCO Hoses//GDE Tune//PML Trans Pan//TransGo HD Shift Kit//MBRP Exhaust

1986 2R Mustang SVO

Soot. Most of the comments for your item 4 center on soot. How well did your tested sample do regarding soot particle suspension?

Engine not broken in at 25k? Perhaps never, huh?

_________________
06 CRD Spoat

Changing the filter wont help. The best full flow oil filters will only filter to 15 micron particles. If your using the stock mopar or wix equivelant then they usually filter down to the 25-40 micron particle range. Most wear metals are much smaller than this and wont be caught in the filter. Most engine damage is caused by smaller particles in the 5-10 micron range. Its kinda like microscopic sand being pumped around your engine. Auto makers know this and suggest oil change intervals based on how many 5-10 micron particles are present in the oil which they know wont be caught in the filter. Using a bypass oil filter can greatly reduce this and usually filter down to the 1 micron range almost eliminating the microscopic sand effect.

Also Blackstone used universal averages for their report. This is a good rough estimate in the condition of your oil. If you truly want a good report, you need to take a baseline sample of the oil just after its changed. This way you can actually compare before and after reports.

Anyway if you get free oil changes at the dealer why wait so long? If it was my engine I would have it in there every 3000 miles?

If you really want to stretch your changes get a bypass filter. Use oil analysis to determine when the TBN and Calcium, Phosphorus, and Zinc (ZDDP) are less than half from your baseline sample. Once these get to half they drop off real quick as the oil has lost most of its addative package. Some products claim they can add ZDDP to your oil and extend its life but for the most part they do not work and its just plain better to change the oil.

There was no direct value listed for soot, just the comment I noted in the original post. I get 2 free oil changes per year so with my 20-22k per year use, I tried to stretch it. As far as doing testing for baseline values, I will let some of the gearheads do that. Beyond finding out that 12k is too long (at present) I don't need any additional information. The unversal average is good for my purposes. I will test again next year, or at about 50k miles. In total the oil seems good to me.

Oh and for stabler: I'm sorry I did not use the slow person font-of course I changed the filter!! Thats what free oil/filter changes mean.

Post all the numbers of the UOA!
Example
http://www.lostjeeps.com/forum/phpBB3/vie ... php?t=4582

Based on some comments here I checked back with Blackstone concerning the oil analysis. First of all, they are excellent people. I noted to them that the engine in the initial report was listed as a VW, not Motori and asked if this would change the "universal levels". They not only corrected the mistake, but credited my whole analysis for next time!

In any event, using the values for Motori, the analysis seems better with metals still high (break in according to Blackstone), but not beyond what would be expected.

I asked about the "soot" level as this is a concern for some with the Mobil 1 0w-40. They reported that there was "excess soot", but that it was not a problem for the oil itself as the viscosity/insoluables were in a normal range. The level of soot is consistant with a breaking in engine. If it does not clear up in 10k miles they suggest I have a combustion problem (but with getting 25mpg I will take that kind of problem)

As for the break in point they reported that at 25k my engine is past what they would normall call the break in period. However, since the oil was put in at about 12.5k it is thought that the break in contaminants did not wash out with the oil change at that time. They said that the next report will be more useful for wear indicators.

Also, you should remember that the I held off on the change to the "max" at 12,000 miles so if you reduced the ppms for the metals by 50% virtually all of the elements would be within normal range for a 6k oil change (which I will do next time).

Blackstone seems to be an attentive, interested lab and I was impressed with their response to my questions.