[tommygun280]

Well, sure a lot of emotion on this topic! I finally bought some ramps today and changed my 2013 335XI's oil at 11,600 miles. The on-board monitoring told me I could wait a year...

I wish I would have changed it at 10,000 miles like the 2014 guidelines are. My oil looked really crappy (very technical here). It bothers me that they changed it for the 2014's but not retroactively for the 2013's with the same engine.

The change was very easy to perform. Plan on keeping the car for a long time so worth the peace of mind to spend the $80 regardless.

Just my 2 cents.

[chiefneil]

Originally Posted by RedlinePSI

Here we go again. Anybody going well over 5K miles on a single oil change is doing harm.

I've had the oil tested a few times in my previous cars (a '95 325i and a 2002 330i). It always came back in support of BMW's schedule for those particular cars. My 2002 330i currently has 110k miles and burns less than a quart between changes. I change the oil roughly once a year which is about 10-12k miles. We had a 2002 X5 with the same engine that followed the same 12 month / 12k schedule and it also went to 110k miles without burning oil.

We traded that X5 for a 2012 X5 35i (N55 engine) and the SA swore up and down that it didn't need an early break-in oil change. I said fine and just let that first oil change go to 10k. On my 2014 335i I was feeling curious, so at 4300 miles I changed the oil and sent in a sample to Blackstone for analysis. I forgot to note the mileage when I sent in the sample (you'll see them mention it's missing), but I did ask Blackstone 2 questions:

1. Did I wait too long to change the break-in oil?
2. Is the oil ok for continued use up to 10k?

Here's their response. It directly contradicts Redline's "over 5K miles on a single oil change is doing harm" statement. But I understand some people aren't swayed by scientific proof and prefer to stick with their instincts. That's fine, it's your car and your money and old habits die hard. But maybe people shouldn't make such absolute statements when they're based on personal habits/beliefs rather than scientific evidence.

Well, it doesn't look like you left the oil in too long, but you didn't tell us how many miles were on this
oil. Universal averages show normal levels of wear for this type of engine after ~5,500 miles of oil use. From
what we can see here, this engine looks great. We were expecting high levels of metals/silicon from the
normal break-in process, but most wear metals are at or below average. The TBN at 4.5 shows lots of active
additive left. 10,000 miles seems possible on future oil changes, but maybe check back in about 6,000 miles
first to see how metals look then.

[snowghost]

I agree that 5k is too short an interval. But what about the fact BMW shortened the old interval on the N55 for 2014?

[m6pwr]

Hopefully someone on this forum will send a sample in for a uoa on a 10k mi drain. I'll do it for sure but I'm only at 4k so it will be awhile. Then we will have something resembling facts to discuss/debate. FWIW, the first drain is always high in wear metals, particularly iron and copper. No big deal.

Until then, we can all educate ourselves on interpretation of uoa's. Here's a good start:
http://digital.ipcprintservices.com/...tion/?i=106542 and http://www.bobistheoilguy.com/what-is-oil-analysis/.

There's almost sure to be some debate/disagreement on what is an acceptable limit of the various metrics reported in the uoa. Just remember the caution mentioned in the first article - that the comments of the labs in this regard are usually on the very conservative side.

[chiefneil]

Originally Posted by m6pwr

Hopefully someone on this forum will send a sample in for a uoa on a 10k mi drain. I'll do it for sure but I'm only at 4k so it will be awhile. Then we will have something resembling facts to discuss/debate. FWIW, the first drain is always high in wear metals, particularly iron and copper. No big deal.

Iron was 33 in my break-in oil, while avg is 56. Copper at 11 and avg is 10. Those are Blackstone's observed averages, I assume.

I think it's pretty astonishing that my break-in oil was at or below average in wear metals compared to non-break in oil. I assume this is due to very close tolerances in BMW's manufacturing processes.

Anyway, I'm pretty comfortable with 10-12k/12month intervals since I've been doing that for the last 10+ years across 3 different BMW's now. I did test some 10k oil on my E46 330i once and that came back ok; it was the M54 engine though.

[m6pwr]

Originally Posted by chiefneil

Iron was 33 in my break-in oil, while avg is 56. Copper at 11 and avg is 10. Those are Blackstone's observed averages, I assume.

I think it's pretty astonishing that my break-in oil was at or below average in wear metals compared to non-break in oil. I assume this is due to very close tolerances in BMW's manufacturing processes.

Anyway, I'm pretty comfortable with 10-12k/12month intervals since I've been doing that for the last 10+ years across 3 different BMW's now. I did test some 10k oil on my E46 330i once and that came back ok; it was the M54 engine though.

Iron wear is linear: the more miles on the oil, the more ppm iron. At a 10k drain the iron would have been higher. UOA's are best employed as a way to monitor the health of the oil at the particular drain interval used and circumstances of operation. I tend to forget that myself, and perhaps focus too much on the wear metals. It's always nice to get a report that shows wear metals within accepted norms Thus Blackstone always makes us feel good when they say "Your engine is wearing nicely." Since BMW ramped back their drain intervals to 10k, doing UOA's may be superfluous - - but I'll do them anyway.

[kyoko]

I've been trying to find documentation on oil change intervals for 2013 and 2014 (335 - n55) in the manual and online and I can't seem to find anything. Where did you guys see the oil change intervals was updated in 2014?

[m6pwr]

It was published in a BMW Service Information Bulletin 000113. Sorry I don't have a link, but your friendly SA might burn a copy for you. The SIB said that all US gas and diesel 2014 model year cars built July 2013 and after will have a 10k mile/1 yr oil change interval. No reason was given for the change. The CBS intervals in the 2014 iDrive reflect the change.