aaks38

Thought this might provide some good info to some of you out there. I just changed the oil on my 07 4S after 8k miles and have 40k on the car. Been using M1 0w-40 with the Mann oil filter. I actually took this oil sample right at the end of my oil drain, so i think it may have picked up a tad more metals but as you can see, they feel 10k oil change interval is suitable for me. I do about 70% highway and 30% city. Its pretty interesting that most people send them samples with an average of 2100 miles on the oil.

Macster

To me the iron number (150% of average) and copper number (200% of average) suggest the oil has broken down some as those are metals from wear.

In my opinion, the idea is to not change the oil after wear metal show up but to change the oil *before* wear metals show up.

I know the comment in the report reads "Try 10000 miles next time."

My comment would be thanks but no thanks. I think based on the numbers 8K is plenty.

Sincerely,

Macster.

blake

Interesting information - thanks for posting.

Personally, I change the synthetic motor oils at 5k (or annually) in my PCars... And in my other cars, 7.5K as I know I will only keep them 3 years or so...

In total, I bet I have spent 20+ hours reading Rennlist oil threads over the years... It is a religious experience!

-B

aaks38

Actually a mistake i made was that Blackstone tells you to collect the oil sample halfway through the oil drain as it better represents the distribution of metals in the oil, i ended up waiting till the end as the oil was dribbling as it was easier to collect. I didnt realize this till after i sent out the sample. But nevertheless i figured this is about the best test you can do to get an idea of whats going on.

But i ended up putting 8k after 1 year of driving, so ill stick to a one year oil change interval.

ADias

Let's see... the report states the following particulates in excess to the average:

- iron - 50% more
- copper - 100% more
- boron - 60% more
- calcium 25% more

Excluding Ca, the metals are an indication of wear, which should be monitored.

It may be that being the end of the drip you got these higher values, but I doubt it.

I think that 8k miles on a boxer engine is too long, especially a M96/M97 engine. I suggest 5-6k miles max.

Alan C.

I almost took 3 samples once from the same oil change. Sequence would have been:

1. Immediately after removing the drain plug. 2. About mid way through the drain, rough guess. 3. At the very end. I might still do this some day.

Fred R. C4S

I always get a kick out of theses oil analysis reports and the "interpretations" offered by the lab or car owners on an internet board. I retired from Caterpillar after 36 years in Engineering, Research, Development, Sales, and Product Support. CAT has provided SOS (Scheduled Oil Sampling) as a service to customers for many years.

What most folks (the independent labs included) don't understand is that there is a science to drawing the samples, and interpreting the readings. CAT engines and all other components using oil (powertrains, hydraulic systems, etc.) are equipped with special quick connectors located in positions to draw "representative" samples of the oil. You don't just suck some oil out of the sump or from the pan into which you drain the oil.

Additionally, as the manufacturer of the mechanical components, CAT has extensive data regarding wear materials present in the oil at various stages throughout the life of the component, Independent labs work from generic data drawn from many different manufacturers lumped together. Yes, they can very accurately tell you what is in the sample, but they aren't quite as clever interpreting the results. On construction equipment, samples are taken every 250 hours up to many thousands of hours a component operates before overhaul. The particle counts for various wear materials may spike early do to "break-in", then level out for a long period before normal begins to take its course. They key to accurately interpreting the results is the history and data the manufacturer has logged over thousands of components for thousands of hours. The independent labs simply don't have data this comprehensive.

So is oil sampling valuable? Yes!
Are the prognostic predictions of the independent labs the best available? No. It's better than nothing, but a lot of folks fret over results based upon oil with very few hours of use. It's just a glimpse into what might be going on.

Lubrecon

Fred R is right on with respect to the oil sample results in question. Without numerous samples from any engine or other component, taken over a period of time, these one shot results really tell you nothing. What you need to establish is a trend of the metals....are they stable or increasing, over how many samples, and under what operating conditions. To compare against and average is also useless because you really want to know about your engine, and where did the average come from???

If you really want to know if there is any unusual wear taking place in your engine, you need to pull a sample each time you change oil and build a history...a trend. As someone with 44+ years in the field of lubrication, I don't know what to say about your sample other than it is the first oil sample on your engine. The metals have nothing to do with the oil breaking down, they are just wear metals generated by the engine running. There could be a very slight fuel dilution as indicated by the viscosity at 210 F and 100 C, and the slight decrease in the Flash, and in fact the lab did indicate that as Trace(TR). But with 8K miles, I would expect that and it is really not a problem.

Pull another sample at your next oil change and try and keep the same sample interval for all subsequent samples. Establish a trend and then you will really know about the wear. But then of course, you might have to decide what to do, and where is it all coming from? Just like Fred said, oil analysis is valuable, but knowing what to do with the data is even more valuable....as always, the devil is in the details.

ADias

Both Fred and Lubrecon are right but there's value in an oil sample. With today's synthetics these are snapshots on engine wear, not oil breakdown.

The Blackstone average is their average for this type of engine and oil type - there's value in that too.

The particulate count is useful as it shows engine wear. As Lubrecon says, a trend should be established and checked. If the metal count is much higher than average on a given sample and does not drop on future samples there may be a problem.

Eric - Plug Guy

All good info, thanks. I've always followed factory recommendations, but b/c I don't put enough miles on the P-cars, I'm in once/year for an annual service for oil and other stuff whether mileage dictates or not.

So yes, I'm paying for it, but I'd rather spend a little now and avoid something bigger later. On the '04 C4S Cab I drove about 4k-5k/year on it (have other vehicles), and now on the Turbo I'm only putting about 3-4k/year on it (note to self: need more turbo time).

So my oil gets replaced with filter and other services once a year.

gota911

Duh, Eric!!!!

gpjli2

Oil change at a good independent is about $160. Going for a long distance oil change record seems counter productive. At some point you may get a report back that says: "shoulda changed the oil 3k miles ago". Where this sort of thing might be useful is to compare wear rates between different oils if indeed the info is that valid and reliable. You'd need a lot of samples though.

vern1

Yes but I think those guys points is relative to what? Does it show engine wear relative to a motor oil change at regular intervals of 10k. Whats the avg metal counts on oils tested at the recommended service change intervals? The avg levels for their test was oil with 2,100 miles which is ridiculously low!! What if they compared it to oil with an avg of 100 miles on it? Then we should likely change our oil every 500 miles as the analysis is surely to show there is 5 times as much metal content. Seems a bit silly to me without some context and testing it against oil with 2,100 miles on seems stupid and drawing any conclusion from such testing irrelevant