[orionredwing]

INTRO:
Sorry, this review is LONG, but I hope worth the read.

There are so many discussions about oil change intervals in this forum. The resulting consensus seems to be we should change our oil around 7,500 miles, or half the recommended 15K factory service interval. I myself adhere to this philosophy, and even though I don’t consistently change at the 7,500 mark, my average interval is pretty close, around 6.8K miles.

But, where’s the data behind this 7.5K assumption? There have been very few oil analysis posted in these forums, so I thought I'd contribute. Lastly, I did a UOA because it would be nice to cater an oil change interval to MY driving style.

COST:
A dealer oil change can cost anywhere from $120 - $160. As for myself, I buy parts from the dealer and have my mechanic change. Still, it’s a hefty ~$90 per oil change ($6 x 7 qts + $20 filter + labor + tax). Even if you were to go through the hassle of changing your oil, it’s probably worthwhile to spend $35 for an UOA - used oil analysis ($25 + $10 for TBN). It’s a hassle, but worth the investment.

DATA:
Mileage: 66K, 9281 on oil
BMW Synthetic 5W-30, 7 qts, 0 qts added
See my signature for all mods.

Because of the Thanksgiving and Xmas holidays, I ended up at 9281 miles for this oil change. Add 2 track days on top of this, and I bet most of you 7.5K mile adherents would say I’m waaaay past due, especially with all my mods. In fact, some of you track experts probably change your oil after each track event.

UOA:
(see attached .pdf for report)

Looks like I was wrong. The analysis came back and the condition of my oil is still good. I paid extra for the TBN analysis showing oil wear, and at 2.0 is just at the point where it needs to be changed. Blackstone recommended next oil change interval at 10K miles. Most importantly, there are no signs of excessive engine wear, although some of my averages appear higher than the baseline (Blackstone didn't comment). Lastly, I’m running catless downpipes, and was concerned about excessive fuel in the oil – there were no problems. All in all, a healthy oil sample at almost 10K miles and 2 track days! Woot!

ANALYSIS:
Take a look at the comment. At 9281 miles, I’m showing typical wear at 4100 miles. Wow, I’m way below the average in how hard I stress my car. Woo hoo, does this mean I can change my oil at 20,000 miles (exaggerating obviously)?!?!!? But wait, I had 2 friggin track days where I redlined my car all day! What the heck?

Well it’s obvious that for daily driving, I’m a pretty sedate driver. I WOT / floor my car once a day, but otherwise am constrained to rush hour traffic. However, ~2K miles are from easy long-distance drives between San Francisco and LA. But, I also wonder if the PROcede’s auto-tune helped? Hate to insert a tune discussion into a UOA thread, but a well tuned car will obviously be beneficial to long-term reliability on a modded car.

The explanation. At first glance, you may think I have plenty of wear left in my oil, but the TBN of 2.0 tells the story. So what’s the reason? Simply, my 2 track days. Read the Blackstone comments for the explanation. If I didn’t do the TBN analysis, I would’ve incorrectly assumed the condition of my oil is still good for a couple more K miles!

CONCLUSION:
With my 6.8K average oil change interval, you can see I’m a big fan of changing oil frequently and even ahead of the 7.5K consensus. But it looks like for MY driving style, with up to 2 track days in the mix, I can extend my oil change interval to 10,000 miles.

The $35 just paid for itself.

Hope the UOA and description of my driving style helps you guys with your own oil change intervals. Regardless, $35 is worth the money and peace of mind, so let's get more UOAs posted here for the community!

UPDATED 1/14/11: Attached revised report showing correct engine type.

Q: What does 'Universal averages show typical wear for BMW's N54 engine after ~5,200 miles on the oil' mean?

A: Universal averages reflects an estimate for a sampling at ~5,200 miles. If your oil change interval was >5,200 miles, you'd expect higher numbers. If <5,200, you'd expect lower numbers.

Black Stone Analysis: "So, for example, the new averages show typical wear after about 5,200 miles on the oil. You ran your oil much longer at 9,200 miles, so we would expect to see some wear higher than averages. That's not really the case since most wear is below average (except for copper), so that means your engine wears better than most."

[Jeff@TopGearSolutions]

Thanks I wish someone running meth would do a UOA.

[ceb]

You do realize that the oil analysis is pretty much useless. It is a single snapshot in time of a modded car that is tracked.

While you may believe that this analysis may mean something for you and your car, it certainly does not mean that people should be change their oil more frequently.

[orionredwing]

No, not useless. Because my review was so long, it's obvious I was clearly stating this UOA applied to my specific driving style, mods, driving conditions, and track time (see above for details!)

And also stated in my conclusion, I truly wish there were more people who would do UOA so we can get a better sampling of the different conditions (e.g. would be cool to have an equivalent of bobistheoilguy on e90post).

It should be obvious I put a lot of thought into writing this review, and at 6.8K miles avg oil change intervals, I'm also an advocate of early oil changes.

I'll be glad to do more UOAs. In fact, I have a 0 track day baseline sample prior to this UOA. I need to call Blackstone to inquire if a 6 month shelf life is acceptable (the faq says no problem).

If anyone else enjoyed this thread and are interested in seeing more UOAs, please chime in!

[Tzu]

Great read. Thanks for taking the time to post this.

I'm a little confused however. Blackstone says you can get a few more miles. But the analysis report shows that your oil was more contaminated than the BMW universal averages at the time of analysis. You state this is probably due to track days. Doesn't this reinforce the paradigm of changing the engine oil after a rough track day?

[e90pilot]

So when and how often would you perform a UOA?

[F32Fleet]

Originally Posted by e90pilot

So when and how often would you perform a UOA?

Eh...if you run long OCI's then it's worth taking a sampe midway through to see how the oil is holding up.

UOA's are good for trending, but IMO the bottom section titled "properties" of the BS analysis is most informative.

Once thing you must understand with most UOA's is that the wear metals are in PPM, and they can only measure particles of a certain size (can't remember exact size in microns) therefore larger wear particles will not be represented.

[F32Fleet]

To the OP: Congrats. You should post this UOA on the BITOG forum. Glad to see flashpoint is still low. I wouldn't worry about the viscosity @ 100C as these euro 30 weight oils generally start out at the top end of the scale.

Everyone should be pleased that this UOA didn't include any top off of motor oil.

[orionredwing]

Thanks! I took your suggestion and posted it on BITOG. It was great to receive feedback from that very knowledgeable forum.

http://www.bobistheoilguy.com/forums...79#Post2136379

Originally Posted by Socom

To the OP: Congrats. You should post this UOA on the BITOG forum. Glad to see flashpoint is still low. I wouldn't worry about the viscosity @ 100C as these euro 30 weight oils generally start out at the top end of the scale.

Everyone should be pleased that this UOA didn't include any top off of motor oil.

[F32Fleet]

Originally Posted by orionredwing

Thanks! I took your suggestion and posted it on BITOG. It was great to receive feedback from that very knowledgeable forum.

http://www.bobistheoilguy.com/forums...79#Post2136379

[McMuffin]

You think you're a fan of frequent oil changes? I change my oil every every two months/1.5k miles Haha

Yea yea waste of money, whatever!

[Tzu]

^ Oil is blood. No downsides to fresh oil.

[e90pilot]

^ Well, you don't see anyone getting a full blood transfusion every 1500 steps do you? :P

[ENINTY]

Originally Posted by McMuffin

You think you're a fan of frequent oil changes? I change my oil every every two months/1.5k miles Haha

Yea yea waste of money, whatever!

Thanks for letting us know that you are an idiot, we'll make a note of it...

[McMuffin]

Originally Posted by ENINTY

Thanks for letting us know that you are an idiot, we'll make a note of it...

no, problem sir

[orionredwing]

LMAO, you guys are hilarious.

[orionredwing]

UPDATE 1/14/11:

Noticed discrepancy in engine type of original report and asked Blackstone to update. Also asked a question regarding universal averages.

Please see original post above for new report. Both original and revised .pdfs included, but also linked an image of the revised report so you don't have to go through the hassle of downloading and opening.

[ENINTY]

You know, I've owned somewhere north of 15 cars in my lifetime and driven a cumulative of almost 1 million miles and I've never, ever, taken a sample of oil and sent it to a lab for analysis. I've just followed the manufacturer's oil recommendations and oil change intervals. I've never had one engine in any of those cars fail, ever.

Why do you guys waste so much time on this crap?

[orionredwing]

Well, for many good reasons. If you were just a regular person who uses his car to commute / vacation, and don't abuse your car, chances are the factory maintenance levels are ok. Plus to have hit 1 million miles, you must pack a lot of highway miles, which is very easy on the car.

However, for me, it's completely different. My car is modified, and I subject it to extreme conditions by tracking it. This isn't a few highway pulls and thrills, it's a whole day of non-stop high RPM to redline at full throttle.

Now....that's VERY HARD on the car! Since I like my car a lot, I don't subscribe to the 'drive it hard till it dies' mentality, so it would be smart of me to also be as aggressive in my maintnenace, wouldn't you agree?

However, that maintenance is very expensive. 15K oil change intervals are no longer reaslistic, but what should I do? 5K, 7.5K, 10K? Doing things like a UOA would help mitigate/optimize my maintenance expense as explained in my Cost paragraph above.

Hope that makes sense.

Originally Posted by ENINTY

You know, I've owned somewhere north of 15 cars in my lifetime and driven a cumulative of almost 1 million miles and I've never, ever, taken a sample of oil and sent it to a lab for analysis. I've just followed the manufacturer's oil recommendations and oil change intervals. I've never had one engine in any of those cars fail, ever.

Why do you guys waste so much time on this crap?

[MatchesMalone]

^ Makes perfect sense to me. Plus, the analysis is pretty cheap. Additionally, if you were to conclude that you can use a longer oil change interval, the money saved from even one less oil change would justify the cost. That's not even counting the peace of mind you can gain.

[ENINTY]

Originally Posted by orionredwing

Well, for many good reasons. If you were just a regular person who uses his car to commute / vacation, and don't abuse your car, chances are the factory maintenance levels are ok. Plus to have hit 1 million miles, you must pack a lot of highway miles, which is very easy on the car.

However, for me, it's completely different. My car is modified, and I subject it to extreme conditions by tracking it. This isn't a few highway pulls and thrills, it's a whole day of non-stop high RPM to redline at full throttle.

Now....that's VERY HARD on the car! Since I like my car a lot, I don't subscribe to the 'drive it hard till it dies' mentality, so it would be smart of me to also be as aggressive in my maintnenace, wouldn't you agree?

However, that maintenance is very expensive. 15K oil change intervals are no longer reaslistic, but what should I do? 5K, 7.5K, 10K? Doing things like a UOA would help mitigate/optimize my maintenance expense as explained in my Cost paragraph above.

Hope that makes sense.

Not that you'd know, but I've been driving for 35+ years, and the mix of hwy/suburban is about 50/50 I estimate and I'm not easy on my cars. I've not tracked any of them, but all of them, outside the trucks I've owned, always see redline daily, and I drive very aggressively. So my cars have never been treated gently. I now live in a rural community with great roads and commute into the DC suburbs. My E90 has a good burring smell most days when I get home from a stress relieving back-road hammering.

Your point, being a modified and tracked car, is well taken, but you are a minority driver, and a minority on this board. I'm not exactly sure what the analysis cost is (I think I remember $35) but since an oil change if you DIY is about $70, dropping the OCI to 7,500 miles balances out. And treating your car to such abuse as you rationalize, you can't possibly expect it to last as long as a normally driven one. So trying to protect it by knowing exactly what condition the oil is in in an effort to keep maintenance costs to a minimum seems incongruent. Tracking, mods, and low maintenance costs are not consistant with each other.

The majority of people on this board claim to use the Blackstone labs (seems like they are the only game in town) to justify not sticking to the BMW service intervals and to call BS on the 15,000 mile OCI. I, on the other hand, have three BMW’s, all of which have been maintained on BMW’s recommended schedules and have achieved operating miles (without any major mechanical problems) of 294,000 (1989 E30), 145,000 miles (1997 Z3 – still in operation), and 132,000 miles (2006 325i E90 – still in operation).

[SupremeTeam]

ENINTY, None of your cars have a N54 in them.