BMW 5W-30, 7471 miles, 1999 BMW 323i

[jpr]

Here's a second analysis on the same oil run -
Last oil change was 11/26/07 at 88,267 miles.
Previous UOA is here - http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Board=3&Number=1194277
A peek under the valve cover and the entire OCI history is here - http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Board=48&Number=1196764

Overall, it seems like there is a lot to be pleased about. Wear rate seems nice and low and fairly even. It is interesting to watch the additive levels deplete. The puzzler though is why the calcium level would go up - sampling error perhaps?

 

[SL8R]

I'm not an expert, but I would have expected the TBN to drop. What is the % error in the TBN from Blackstone?

 

[mva]

Very interesting info. Your history, UOA results and photos are amazing given the long OCI's.

BMW's 5W30 oil and OCI based on the oil life monitor are working very well for you.

San Diego location, driving style and climate might be a factor?

 

[buster]

Very nice results. The BMW/Castrol 5w30 is a solid oil.

 

[jpr]

Originally Posted By: SL8R
I'm not an expert, but I would have expected the TBN to drop. What is the % error in the TBN from Blackstone?
I don't know, but I was thinking along the same lines as you and not putting much significance on the difference.
Originally Posted By: mva
Very interesting info. Your history, UOA results and photos are amazing given the long OCI's.

BMW's 5W30 oil and OCI based on the oil life monitor are working very well for you.

San Diego location, driving style and climate might be a factor?
I've been pleasently surprised by both UOA's and the valve cover inspection as one does hear so much chatter about how crazy BMW's OCI's must be. But as you point out, it's clearly working pretty well for me.

I have no doubt the benign climate in San Diego plays a role in keeping condensation contamination down as it never gets particularly humid or particularly cold here.
Originally Posted By: buster
Very nice results. The BMW/Castrol 5w30 is a solid oil.
It certainly has done right by me. My plan is to keep running it until around 18 months and 11k miles or so and then sample it again.

 

[Jim 5]

I've always said it's a sleeper oil. Great value for money, and conservative at 7.5k miles intervals.