Hi, I've been lurking around here for a while and I figure I might as well make my first post a useful one.

I did an oil analysis recently and here's the report.







The car has about 17,000 km on it. I changed the engine oil to 10W30 Royal Purple at 1700 km, 4100 km, and 8500 km. The sample in the test has about 8400 km on it. I've switched to Motul 8100 5W30 since, and I plan to do another test after a few more changes.

I'm a bit worried about the Iron and Chromium readings. Is that normal for a rotary engine at this mileage?

I wonder if I've contaminated the sample because I used an empty oil container that previously had new oil in it, then I cleaned it out thoroughly with brake cleaner and mixed up the changed out oil well, instead of following their instructions (which I later found) and take samples in mid-drain.


Update (April 8th):

They sent me the revised report that includes the TBN value which they have left out on the previous one, and my TBN value after 8400 km is 2.0. The initial TBN value is 7.5.

 

Useful info. Thanks. Keep us updated.

 

always use clean bottle and always get the sample during middle of the drain.

I did a report b4, but mine doesnt have a picture like yours.

Its been like over 15K miles since my last report I think. maybe time to do another one.

 

Yes, thank you. I only realize that after the sample was sent in. The picture is extra I believe. I had no idea what the test does, I just checked it off for the heck of it. I don't think I'll do that again next time unless it's somehow useful information.

So does anyone know if rotary engine wears a bit differently than normal engines? Or rather, should this report be interpretted the same way as normal gas engines?

 

Here's an analysis on my car at 18K miles to use as a comparison.

 

Oil analysis for a rotary are less useful that for our piston counterparts as most of our wear concerns are from rotor and apex seals and oil analysis does not show this king of wear as they are not lubricated via recirculated sump oil (lbed from injected and burned oil).

That said, it can show internal rotor gear and bearing wear.

Chromium does tend to run higher on a rotary via these oil analysis. Iron seems a little high as well on your read.

One thing to note on oil analysis is that when you change oils, especially to an ester-based oil, they tend to do a lot of deposit cleanup and can skew your results to the high side from the cleanup and not any actual wear - so the total story of oil used, switching, miles, etc is very important to go with the actual numbers to see what is really going on.

It is also important to compare the numbers to the Virgin Oil Analysis (VOA) of the unused fluid you started with.

Hope this helps

 

Yours look a lot better than mine. Thanks.


Yea, that does help and it makes some sense. I'll be sure to do a better job of sampling next time.

Does anyone know what the particle count photo does? If I don't order the particle count test, does that mean I won't get the ppm readings?

 

They sent me the revised report that includes the TBN value which they have left out on the previous one, and my TBN value after 8400 km is 2.0.

 

Update: According to Royal Purple, the initial TBN for 10w30 is 7.5.